HAND-BOOK 


OF 


INDUSTRIAL  QRGANIC  QHEMISTRY 


ADAPTED    FOR    THE    USE    OF 


MANUFACTUEEES,  CHEMISTS,  AND  ALL  LNTEEESTED  IN 

THE  UTILIZATION  OF  OEGANIC  MATEEIALS 

IN  THE  INDUSTEIAL  AETS. 


BY 

SAMUEL  P.KSADTLER,  PH.D.,  F.C.S., 

CONSULTING  CHEMIST  ;    PROFESSOR  OP  CHEMISTRY  IN   THE  PHILADELPHIA    COLLEGE   OF    PHARMACY  ANI> 

IN  THE  FRANKLIN  INSTITUTE  OF  THE  STATE  OF  PENNSYLVANIA  ',    SOMETIME  PROFESSOR  OF 

ORGANIC  AND  INDUSTRIAL  CHEMISTRY  IN  THE  UNIVERSITY  OF  PENNSYLVANIA. 


THIRD  REVISED  AND  ENLARGED  EDITION. 


PHILADELPHIA : 

J.  B.  LIPPINCOTT   COMPANY. 

LONDON:  5  HENRIETTA  STREET,  COVENT  GARDEN. 
1906. 


Copyright,  1891,  by  SAMUEL  P.  SADTLER. 


Copyright,  1895,  by  SAMUEL  P.  SADTLER. 


Copyright,  1900,  by  SAMUEL  P.  SADTLER. 


All  rights  reserved. 


ELICTROTVPEO  AND  PRINTED  BY  J.  B.  LIPPINCOTT  COMPANY,  PHILADELPHIA,  U.S.A. 


PREFACE  TO  THE  THIRD  EDITION. 


THE  subject  of  Industrial  Organic  Chemistry  covers  such  a  wide  range 
of  topics  and  considers  the  utilization  of  such  a  variety  of  raw  materials 
of  both  animal  and  vegetable  origin,  and  the  production  of  such  a  multi- 
tude of  useful  and  valuable  substances,  that  a  thorough  survey  of  the  ground 
is  a  laborious  undertaking.  Nevertheless,  the  lapse  of  five  years  since  the 
appearance  of  the  previous  edition  of  this  work  makes  such  a  survey  neces- 
sary, as  notable  advances  have  been  made  in  many  of  the  chemical  industries 
during  that  time. 

Every  chapter,  therefore,  has  been  revised  and  new  matter  added,  while 
older  and  less  important  portions  have  been  stricken  out.  The  chapters 
on  Natural  and  Artificial  Dye-colors  have  been  largely  rewritten,  because 
of  the  rapid  progress  in  discovery  in  these  lines  during  the  last  few  years. 
It  has  been  sought  to  incorporate  in  the  book  all  of  this  advance  in  our 
knowledge  that  is  definitely  accepted  by  chemists.  Several  new  tabular 
statements  have  also  been  incorporated  in  these  chapters,  which  it  is  hoped 
will  prove  of  value. 

The  chapters  on  Fatty  Oils,  Essential  Oils,  Fermentation,  Tanning, 
Textile  Fibres,  and  Destructive  Distillation  have  had  important  additions 
made  to  them. 

The  Bibliography  has  in  all  chapters  been  brought  down  to  date,  and  the 
Statistics  are  the  most  recent  attainable.  The  author  desires  to  acknow- 
ledge his  indebtedness  to  numerous  friends  and  correspondents  for  items  of 
valuable  information  not  readily  accessible. 

American  chemical  industry  has  advanced  with  rapid  strides  in  recent 
years,  and  the  need  of  a  thorough  understanding  of  the  chemical  character 
and  possibilities  of  materials  is  becoming  every  day  better  appreciated  by 
our  manufacturers  as  a  class.  The  author  hopes  that  the  book  may  con- 
tinue to  serve,  as  it  has  already  served  in  the  past,  in  bringing  about  this 
desirable  consummation. 

PHILADELPHIA,  October,  1900. 


iii 


PREFACE  TO  THE  FIRST  EDITION. 


THE  literature  of  Applied  Chemistry  is  reasonably  voluminous.  We 
have  dictionaries  and  encyclopaedic  works  upon  the  subject,  a-series  of 
small  hand-books  for  individual  industries,  and  a  mass  of  technical  journals 
of  both  general  and  special  application.  Works,  however,  in  which  the 
effort  is  made  to  give  within  the  bounds  of  a  single  volume  a  general  view 
of  the  various  industries  based  upon  the  applications  of  chemistry  to  the 
arts  are  much  rarer,  and  especially  is  this  true  of  works  printed  in  the  Eng- 
lish language.  In  German  we  have  Wagner's  "  Chemische  Technologic," 
brought  down  to  date  by  its  present  editor,  Ferd.  Fischer ;  Post's  "  Chem- 
ische Technologic,"  Bolley's  "  Technische-Chemische  Untersuchungen," 
Heinzerling's  "  Technische  Chemie,"  Ost's  "  Chemische  Technologic,"  and 
others ;  in  French,  Pay  en's  "  Chimie  Industrielle"  and  Girardin's  "  Chimie 
applique*  aux  Arts  Industriels,"  etc. ;  while  in  English  we  have  only  the 
now  antiquated  translations  of  Wagner  and  Payen.  In  speaking  thus,  the 
writer  wishes  to  be  understood  as  referring  only  to  general  works  on  chemical 
technology  of  moderate  size.  The  excellent  "  Dictionary  of  Applied  Chem- 
istry," in  three  volumes,  now  being  published  by  Longmans  &  Co.,  does 
not  therefore  come  into  the  consideration,  for  the  twofold  reason  of  its  size 
and  of  its  encyclopaedic  and  disconnected  method  of  treatment. 

Similarly,  works  which  cover  only  a  single  side  of  the  subject,  like  Allen's 
"  Commercial  Organic  Analysis,"  are  not  referred  to  in  the  above  statement. 

The  author  has  endeavored  within  the  compass  of  a  moderate-sized 
octavo  to  take  up  a  number  of  the  more  important  chemical  industries  or 
groups  of  related  industries,  and  to  show  in  language  capable  of  being  under- 
stood even  by  those  not  specially  trained  in  chemistry  the  existing  conditions 
of  those  industries.  The  present  volume,  it  will  be  noticed,  is  limited  to 
"  Industrial  Organic  Chemistry."  This  field,  while  covering  many  very 
important  lines  of  manufacture,  does  not  seem  at  present  to  be  so  well  pro- 
vided for  as  the  inorganic  part  of  the  subject.  A  companion  volume, 
covering  this  other  side  of  industrial  chemistry,  is  in  contemplation. 

In  taking  up  the  several  industries  for  survey,  it  has  been  thought  de- 
sirable first  to  enumerate  and  describe  the  raw  materials  which  serve  as  the 
basis  of  the  industrial  treatment ;  second,  the  processes  of  manufacture  are 
given  in  outline  and  explained ;  third,  the  products,  both  intermediate  and 
final,  are  characterized  and  their  composition  illustrated  in  many  cases  by 
tables  of  analyses ;  fourth,  the  most  important  analytical  tests  and  methods 


vi  PREFACE. 

are  given,  which  seem  to  be  of  value  either  in  the  control  of  the  processes 
of  manufacture  or  in  determining  the  purity  of  the  product ;  and,  fifth,  the 
bibliography  and  statistics  of  each  industry  are  given,  so  that  an  idea  of  the 
present  development  and  relative  importance  of  the  industry  may  be  had. 

The  author  has  endeavored  in  a  number  of  cases  to  give  a  clearer  picture 
of  the  lines  of  treatment  for  an  industry  by  the  introduction  of  schematic 
views  of  the  several  processes  through  which  the  raw  material  is  carried 
until  it  is  brought  out  as  the  finished  product.  A  number  of  these  dia- 
grams have  been  taken  from  German  and  English  sources,  and  several  have 
been  constructed  by  the  author  specially  for  this  work.  A  list  of  these 
diagrams  will  be  found  appended. 

A  large  number  of  the  illustrations  have  been  drawn  specially  for  this 
work,  and  others  have  been  procured  from  the  best  German  and  American 
sources. 

Frequent  foot  references  are  made  to  authorities  and  sources  of  informa- 
tion, although  this  may  not  have  been  done  in  all  cases.  The  author  has  in 
the  analytical  section  made  frequent  use  of  Allen's  "  Commercial  Organic 
Analysis,"  and  hereby  desires  to  acknowledge  his  special  indebtedness  to 
that  most  valuable  work.  He  has  also  made  frequent  use  of  Wagner's 
"Chemische  Technologic,"  thirteenth  edition,  and  Stohmann  and  KerPs 
"  Angewandte  Chemie."  Besides  these  works  of  a  general  character  he  has 
also  consulted  a  large  number  of  special  works,  the  titles  of  which  will  be 
found  in  the  bibliographical  lists  appended  to  each  chapter. 

The  author  desires  here  to  acknowledge  his  indebtedness  to  the  many 
friends  who  have  aided  him  by  information  and  helped  him  especially  in 
the  collating  of  the  statistics  of  the  several  industries. 

His  special  indebtedness  is  due  to  his  friend  and  former  pupil,  Mr.  Louis 
J.  Matos,  M.E.,  who  aided  him  in  the  completion  of  Chapters  XI.  and  XII., 
and  to  whom  Chapter  XIV.  in  its  entirety  belongs. 

To  his  colleague,  Professor  Henry  Trimble,  of  the  Philadelphia  College 
of  Pharmacy,  he  is  also  indebted  for  information  upon  the  subject  of  Tannin 
and  Dye-woods,  as  treated  in  Chapter  XIII. 

The  original  drawings  made  for  this  work  and  the  index  are  also  due  to 
Mr.  L.  J.  Matos. 

The  author  hopes  that  this  work  may  prove  of  some  value  to  those  en- 
gaged in  the  several  lines  of  manufacturing  industry  touched  upon  by  show- 
ing the  chemical  nature  of  the  materials  which  are  handled  by  them,  and  of 
the  change  which  these  materials  undergo  in  the  course  of  treatment  and 
preparation  as  marketable  commodities ;  that  it  may  be  suggestive  to  those 
engaged  in  research  or  invention  in  connection  with  chemistry ;  and,  lastly, 
that  it  may  be  found  to  possess  some  interest  for  the  general  reader  or  the 
student  of  scientific  or  economic  topics. 

PHILADELPHIA,  August  3,  1891. 


PREFACE  TO  THE  SECOND  EDITION. 


THE  fact  that  a  large  edition  of  this  work  has  been  exhausted  in  about 
three  and  one-half  years,  and  that  the  book  has  been  temporarily  out  of 
print,  leads  the  author  to  believe  that  the  plan  of  treatment  adopted  in  the 
book  was  an  acceptable  one,  and  that  such  a  book  was  needed.  While 
some  of  the  author's  correspondents  have  referred  to  the  very  condensed 
treatment  which  some  of  the  industries  necessarily  received,  others  have 
recognized  that  this  feature  particularly  commended  it  as  a  convenient 
hand-book,  or  as  a  text-book  for  students.  For  those  who  wish  the  fullest 
information  on  particular  subjects  the  Bibliography  will  go  far  towards 
indicating  the  sources  for  its  supply.  Were  it  not  for  the  great  range  of 
scientific  periodicals  through  which  new  communications  are  scattered,  the 
journal  literature  might  also  be  cited.  In  a  German  translation  of  the 
work,  which  has  appeared  recently,  by  Dr.  J.  Ephraim,  published  by  Jos. 
Ambrosius  Barth,  Leipzig,  this  reference  to  the  journal  literature  has  been 
attempted  and  partially  carried  through.  The  author,  however,  has  not 
taken  it  up  for  the  reason  stated. 

In  the  present  edition  the  Bibliography  has  in  all  cases  been  rewritten 
and  brought  carefully  to  date.  The  Statistics  have  also  been  brought  down 
to  the  present  year  whenever  new  figures  were  attainable,  and  a  number  of 
new  statistical  tables  have  been  added. 

While  the  body  of  the  text  has  not  been  altered,  numerous  corrections 
have  been  made  and  new  sections  inserted  in  many  cases. 

In  the  Appendix  two  new  tables  have  been  added  giving  the  physical 
and  chemical  constants  of  the  oils,  fats,  and  waxes,  classified  for  reference 
and  comparison. 

The  author  desires  to  acknowledge  his  indebtedness  to  many  friends  for 
kind  suggestions,  and  in  especial  to  Mr.  Louis  J.  Matos,  who  supplied 
information  in  connection  with  the  last  three  chapters,  and  to  Mr.  Samuel 
S.  Sadtler,  who  aided  in  gathering  statistics  and  in  reading  proofs. 

Hoping  that  the  book  will  again  meet  the  public  approval  and  prove 
useful  and  suggestive  to  those  interested,  the  author  submits  this  new  edition. 

PHILADELPHIA,  August,  1895. 


vii 


TABLE  OF  CONTENTS. 


CHAPTER   I. 

PETROLEUM    AND   MINERAL    OIL    INDUSTRY.  PAGES 

I. — Raw  Materials i3-*7 

1.  Natural  Gas,  13.  2.  Crude  Petroleum,  14-16.  3.  Crude  Paraffine,  16. 
4.  Bitumen  and  Asphalt,  16,  17. 

II. — Processes  of  Treatment 17-28 

1.  Of  Natural  Gas,  17,  19.  2.  Of  Crude  Petroleum,  19-26.  3.  Of 
Ozokerite  and  Natural  Paraffine,  26.  4.  Of  Natural  Bitumens  and 
Asphalts  and  of  Bituminous  Shales,  26-28. 

III. — Products 28-32 

1.  From  Natural  Gas  (a,  Fuel  Gas  ;  &,  Illuminating  Gas  ;  c,  Lamp-black  ; 
and,  rf,  Electric-light  Carbons),  28,  29.  2.  From  Petroleum,  29-31. 

3.  From  Ozokerite  and  Natural  Paraffine,  31.     4.  From  Bitumens, 
Asphalts,  and  Bituminous  Shales,  31,  32.     5.  Vaseline,  32. 

IV. — Analytical  Tests  and  Methods 33-43 

1.  For  Natural  Gas,  33.    2.  For  Petroleum,  33-42.    3.  For  Ozokerite,  42. 

4.  For  Asphalts,  42,  43. 

V. — Bibliography  and  Statistics 43-47 

CHAPTER   II. 

INDUSTRY   OF   THE   FATS   AND   FATTY    OILS. 

I. — Raw  Materials 48-58 

1.  Occurrence  of  the  Materials  (a,  Vegetable  Oils,  Fats,  and  Waxes  ;  &, 
Animal  Oils,  Fats,  and  Waxes),  48-52.  2.  Physical  and  Chemical 
Characters  of  the  Different  Oils  and  Fats,  52-54.  3.  Extraction  of 
the  Raw  Materials  and  Purification  of  the  same,  54-58. 

II. — Processes  of  Treatment 58-72 

1.  Saponification  of  Fats,  58-60.  2.  Practical  Soap-making,  60-66. 
3.  Stearic  Acid  and  Candle  Manufacture,  66-70.  4.  Oleomargarine 
or  Artificial  Butter  Manufacture,  70.  5.  Glycerine  Manufacture 
(5a,  Nitro-glycerine  and  Dynamite),  70-72. 

III. — Products  . 72-78 

1.  Purified  Oils,  Fats,  and  Waxes,  and  Products  from  the  same,  72-74. 
2.  Soaps,  74-76.  3.  Candles,  76.  4.  Oleomargarine  or  Butterine, 
76.  5.  Glycerine  and  Nitro-glycerine,  76-78. 

IV. — Analytical  Tests  and  Methods 78-87 

1.  For  Oils  and  Fats,  78-83.    2.  For  Soaps,  83-85.    3.  Glycerine,  86,  87. 

V. — Bibliography  and  Statistics 87-93 

CHAPTER   III. 

INDUSTRY   OF    THE    ESSENTIAL    OILS   AND   RESINS. 

I. — Raw  Materials ,    .    .    94-100 

1.  Essential  Oils,  94-97.  2.  Resins,  97,  98.  3.  Caoutchouc,  99.  4.  Gutta- 
percha  and  Similar  Products,  99,  100.  5.  Natural  Varnishes,  100. 

ix 


x  TABLE  OF   CONTENTS. 

PACKS 

II. — Processes  of  Treatment 100-108 

1.  Manufacture  of  Perfumes  and  Similar  Products,  100,  101.  2.  Manu- 
facture of  Varnishes,  101-104.  3.  Manufacture  of  Printer's  Ink, 
104,  105.  4.  Manufacture  of  Oil-cloth,  Linoleum,  etc.,  105.  5. 
Processes  of  Treatment  of  Caoutchouc  and  Gutta-percha,  105-108. 

III. — Products 108-112 

1.  Perfumes,  108.  2.  Varnishes,  108-110.  3.  Printing  Inks,  110.  4. 
Miscellaneous  Products  from  Resins  and  Essential  Oils,  110,  111. 
5.  India-rubber  and  Gutta-percha  Products,  111,  112. 

IV. — Analytical  Tests  and  Methods 112-116 

1.  For  Essential  Oils,  112-114.  2.  For  Resins,  114,  115.  3.  For  Var- 
nishes, 116.  4.  For  Caoutchouc  and  Gutta-percha,  116. 

V. — Bibliography  and  Statistics 116-120 

CHAPTER   IV. 

THE   CANE-SUGAR   INDUSTRY. 

I. — Raw  Materials 121-125 

1.  The  Sugar-cane,  121.  2.  Sugar-beet,  121,  122.  3.  Sorghum  Plant, 
122.  4.  The  Sugar-maple,  122,  123. 

II. — Processes  of  Treatment 125-152 

1.  Production  of  Sugar  from  the  Sugar-cane,  125-137.  2.  Production 
of  Sugar  from  the  Sugar-beet,  137-145.  3.  The  Working  up  of 
the  Molasses,  145-150.  4.  Revivifying  of  the  Bone-black,  150-152. 

III. — Products  of  Manufacture 152-156 

1.  Raw  Sugars,  152,  153.  2.  Refined  Sugars,  153.  3.  Molasses  and 
Cane-sugar  Syrups,  153,  154.  4.  Miscellaneous  Side-products, 
154-156. 

IV. — Analytical  Tests  and  Methods 156-165 

1.  Determination  of  Sucrose,  156-159.  2.  Determination  of  Glucose, 
or  Invert  Sugar,  159,  160.  3.  Analysis  of  Commercial  Raw 
Sugars,  160,  161.  4.  Analyses  of  Molasses  and  Syrups,  161,  162. 
5.  Analyses  of  Sugar-canes  and  Sugar-beets  and  Raw  Juices  there- 
from, 162,  163.  6.  Analyses  of  Side-products,  163-165. 

V. — Bibliography  and  Statistics 166, 167 

CHAPTER   V. 

THE    INDUSTRIES   OF   STARCH    AND    ITS   ALTERATION   PRODUCTS. 

I. — Raw  Materials 168-170 

II. — Processes  of  Manufacture 170-176 

1.  Extraction  and  Purifying  of  the  Starch,  170-172.  2.  Manufacture  of 
Glucose,  or  Grape-sugar,  172-174.  3.  Manufacture  of  Maltose, 
174,  175.  4.  Manufacture  of  Dextrine,  175.  5  Manufacture  of 
Sugar-coloring,  175,  176. 

III. — Products 176-178 

1.  Starch,  176.  2.  Glucose  and  Grape-sugar,  176,  177.  3.  Maltose, 
177.  4.  Dextrine,  177,  178.  5.  Unfermentable  Carbohydrates, 
178. 

IV. — Analytical  Tests  and  Methods 178-182 

1.  For  Starch,  178-180.  2.  For  Glucose,  or  Dextrose,  180.  3.  For 
Maltose,  180.  4.  Dextrine,  180.  5.  Commercial  Glucose  and 
Similar  Mixtures  derived  from  Starch,  180-182. 

V. — Bibliography  and  Statistics 182, 183 


TABLE   OF  CONTENTS.  xi 

CHAPTEK  VI. 

FERMENTATION    INDUSTRIES. 

A. — Nature  and  Varieties  of  Fermentation,  184-187. 

B. — Malt  Liquors  and  the  Industries  connected  therewith. 

PAGES 

I. — Raw  Materials 187-189 

1.  Malt,  187,  188.     2.  Hops,  188,  189.     3.  Water,  189. 

II. — Processes  of  Manufacture 189-196 

1.  Malting  of  the  Grain,  189-191.    2.  Preparation  of  the  Wort,  191^194 

3.  Boiling  and  Cooling,  194,  195.     4.  Fermentation  of  the  Wort, 
195,  196. 

III.— Products 196, 197 

IV. — Analytical  Tests  and  Methods 197-201 

1.  For  Malt,  197,  198.     2.  For  Beer-worts,  199.    3.  For  Beer,  199-201. 

C.—The  Manufacture  of  Wine. 

I. — Raw  Materials 201-203 

1.  The  Grape,  201,  202.     2.  The  Must,  202,  203. 

II. — Processes  of  Manufacture : 203-208 

1.  Fermentation,  203,  204.  2.  Diseases  of  Wines  and  Methods  of  Treat- 
ing and  Improving  them,  204-206.  3.  Manufacture  of  Efferves- 
cing Wines,  206,  207.  4.  Manufacture  of  Fortified,  Mixed,  and 
Imitation  Wines,  207,  208. 

III. — Products 208-211 

IV. — Analytical  Tests  and  Methods 212-215 

D. — Manufacture  of  Distilled  Liquors,  or  Ardent  Spirits. 

I. — Raw  Materials 216,  217 

1.  Alcoholic  Liquids,  216.  2.  Sugar-containing  Kaw  Materials,  216, 
217.  3.  Starch-containing  Kaw  Materials,  217. 

II. — Processes  of  Manufacture 217-226 

1.  Preparation  of  the  Wort,  217,  218.  2.  Fermentation  of  the  Wort, 
or  Saccharine  Liquid,  218,  219.  3.  Distillation  of  the  Fermented 
Mash,  or  Alcoholic  Liquid,  220-223.  4.  Rectifying  and  Purifying 
of  the  Distilled  Spirit,  223-226.  5.  Manufacture  of  Alcoholic 
Beverages  from  Rectified  Spirit,  226. 

III. — Products 226-230 

1.  Rectified  and  Proof  Spirit,  226,  227.  2.  Alcoholic  Beverages  made 
by  Direct  Distillation  of  the  Fermentation  Products,  227,  228.  3. 
Alcoholic  Beverages  made  from  Grain  Spirit  by  Distillation  under 
Special  Conditions,  228.  4.  Liqueurs  and  Cordials,  228,  229.  6. 
Side-products,  230. 

IV. — Analytical  Tests  and  Methods 230, 231 

E. — Bread-making. 
I. — Raw  Materials 232-234 

1.  Flour,  232,  233.  2.  Yeast,  or  Ferment,  233,  234.  3.  Baking-pow- 
ders, 234. 

II. — Processes  of  Manufacture 235,  236 

1.  The  Mixing  of  the  Dough  and  its  Fermentation,  235.  2.  Baking, 
235.  3.  The  Use  of  Chemicals  Foreign  to  the  Bread,  235,  236. 

III.— Products 236,237 

1.  Bread,  236,  237.     2.  Crackers  and  Hard  Biscuit,  237. 

IV. — Analytical  Tests  and  Methods 237-239 

1.  For  the  Flour,  237-239.     2.  For  Bread,  239. 


xii  TABLE  OF  CONTENTS. 

F. — The  Manufacture  of  Vinegar 

PAGES 
I. — Raw  Materials 240,  241 

II. — Processes  of  Manufacture 241-244 

1.  The  Orleans  Process,  241,  242.  2.  The  Quick-vinegar  Process,  242, 
243.  3.  The  Manufacture  of  Malt  Vinegar,  243.  4.  The  Manu- 
facture of  Cider  Vinegar,  243.  5.  Pasteur's  Process  for  Vinegar- 
making,  243,  244. 

III.— Products 244,245 

IV. — Analytical  Tests  and  Methods 245 

V. — Bibliography  and  Statistics  for  Fermentation  Industries 246-250 

CHAPTER  VII. 

MILK   INDUSTRIES. 

I. — Raw  Materials 251-253 

II. — Processes  of  Manufacture 253-260 

1.  Manufacture  of  Condensed  and  Preserved  Milk,  253,  254.  2.  Of 
Butter,  254-256.  3.  Of  Artificial  Butter  (Oleomargarine),  256- 
258.  4.  Cheese-making,  258-260. 

III.— Products 260-265 

1.  Condensed  and  Preserved  Milk,  260,  261.  2.  Butter  and  Butter 
Substitutes,  261,  262.  3.  Cheese,  262,  263.  4.  Milk-sugar,  263. 
5.  Koumiss,  264.  6.  Kephir,  264.  7.  Casein  Preparations,  264, 
265.  8.  Whey,  265. 

IV.— Analytical  Tests  and  Methods 265-270 

1.  For  Milk,  265-267.     2.  For  Butter,  267-270.     3.  For  Cheese,  270. 

V.— Bibliography  and  Statistics 270-272 

CHAPTER  VIII. 

VEGETABLE   TEXTILE   FIBRES. 

I. — General  Characters 273-281 

1.  Cotton  Fibre,  274,  275.  2.  Flax,  275-277.  3.  Hemp,  277.  4.  Jute, 
277,  278.  5.  Miscellaneous  Vegetable  Fibres,  278-280.  6.  Clas- 
sification of  the  Vegetable  Fibres,  280,  281. 

INDUSTRIES   BASED   UPON   THE   UTILIZATION   OF   VEGETABLE   FIBRES. 

A . — Paper-making. 

I. — Raw  Materials 281-283 

1.  Rags,  281,  282.  2.  Esparto,  282.  3.  Straw,  282.  4.  Jute,  282.  5. 
Manila  Hemp,  282.  6.  Wood  Fibre,  282,  283.  7.  Paper-mul- 
berry, 283. 

II. — Processes  of  Treatment 283-292 

1.  Mechanical  Preparation  of  the  Paper-making  Material,  283,  284. 
2.  Boiling,  284.  3.  Washing,  284-286.  4.  Bleaching,  286-289. 
5.  Beating,  289.  6.  Loading,  Sizing,  Coloring,  etc.,  289,  290. 
7.  Manufacture  of  Paper  from  the  Pulp,  290-292. 

III. — Products  ( Different  Varieties  of  Paper) 292,293 

IV. — Analytical  Tests  and  Methods     293-295 

1.  Determination  of  the  Nature  of  the  Fibre,  293-295.  2.  Determina- 
tion of  the  Nature  of  the  Loading  Materials,  295.  3.  Determina- 
tion as  to  Nature  of  the  Sizing  Materials,  295.  4.  Determination 
of  the  Nature  of  the  Coloring  Material,  295. 

B. — Gun-cotton,  Pyroxyline,  Collodion,  and  Celluloid. 

I. — Raw  Materials 295,  296 

II. — Processes  of  Manufacture 296-299 

1.  Gun-cotton,  296.  2.  Pyroxyline  and  Collodion,  297,  298.  3.  Cel- 
luloid, 298,  299. 


TABLE  OF   CONTENTS.  xiii 

PAGES 

III.— Products 299,300 

1.  Gun-cotton,  299.     2.  Pyroxyline,  299.     3.  Collodion,  299.     4.  Py- 
roxyline  Varnishes,  299.     5.  Celluloid,  299,  300. 

IV. Analytical  Tests  and  Methods 300,301 

V. Bibliography   and    Statistics  of  Vegetable    Fibres    and   their   Indus- 
tries         301-304 

CHAPTER   IX. 


TEXTILE   FIBRES   OF   ANIMAL    ORIGIN. 


I.— Raw  Materials 305-309 

A.  Wool  and  Animal  Hairs,  305-307.     B.  Silk,  307-309. 

II. — Processes  of  Manufacture  or  Treatment 310-313 

A.  Wool.—  1.  Wool-scouring,  310,  311.     2.  Bleaching  of  Wool,  811. 

B.  Silk.— I.  Reeling  of  Silk,  311.     2.  Silk-conditioning,  311   312.     3. 

Silk-scouring,  312,  313. 
B.  1.  Artificial  Silk,  313 

III.— Products 314,315 

A.  Woollen  Products,  314.     B.  Silken  Products,  314,  315. 

IV.— Analytical  Tests  and  Methods 3*5, 3*6 

V.— Bibliography  and  Statistics 316-319 

CHAPTER   X. 

ANIMAL   TISSUES   AND    THEIR  PRODUCTS. 

A. — Leather  Industry. 
I. — Raw  Materials 320-324 

1.  Animal  Hides  and  Skins,  320,  321.  2.  Tannin-containing  Materials, 
321-324. 

II.— Processes  of  Manufacture 324-333 

A.  Manufacture  of  Sole-Leather,  324-329.  B.  Upper  and  Harness 
Leathers,  329.  C.  Morocco  Leather,  329.  D.  Mineral  Tanning 
or  "Tawing,"  329-332.  E.  Chamois  and  Oil-tanned  Leather, 
332,  333. 

III.— Products 333-335 

1.  Sole-leather,  333.  2.  Upper  and  Harness  Leathers,  333.  3.  Morocco 
Leather,  333.  4.  Enamelled  or  Patent  Leathers,  333,  334.  5. 
Russia  Leather,  334.  6.  Chamois  Leather,  334.  7.  White-tanned 
or  "Tawed"  Leather,  334.  8.  Crown  Leather,  334.  9.  Parch- 
ment and  Vellum,  334.  10.  Degras,  335. 

IV. — Analytical  Tests  and  Methods 335-338 

1.  Qualitative  Tests  for  the  Several  Tanning  Materials,  335.  2.  Deter- 
mination of  Strength  of  Tanning  Infusions,  335.  3.  Quantitative 
Estimation  of  Tannin,  335,  336.  4.  Determination  of  Acidity  of 
Tan-liquors,  336-338. 

B. — Glue  and  Gelatine  Manufacture. 

I. — Raw  Materials 338,339 

1.  Hides  and  Leather,  338.  2.  Bones,  339.  3.  Fish-bladders,  339.  4. 
Vegetable  Glue,  339. 

II. — Processes  of  Manufacture 339-342 

1.  Manufacture  of  Glue  from  Hides,  339-341.  2.  Manufacture  of  Glue 
from  Leather- waste,  341.  3.  Manufacture  of  Glue  or  Gelatine 
from  Bones,  341.  4.  Manufacture  of  Fish  Gelatine,  341,  342. 

III. — Products 342,343 

1.  Hide  Glue,  342.  2.  Bone  Glue  (or  Bone  Gelatine),  342.  3.  Isinglass 
(or  Fish  Gelatine),  342.  4.  Liquid  Glue,  342,  343. 


xiv  TABLE   OF   CONTENTS. 

PAGES 

IV. — Analytical  Tests  and  Methods      343 

1.  Absorption  of  Water,  343.  2.  Inorganic  Impurities,  343.  3.  Adul- 
teration of  Isinglass  with  Glue,  343 

V. — Bibliography  and  Statistics  of  Leather  and  Glue  and  Gelatine  .    .    .    343-346 

CHAPTEK   XI. 

INDUSTRIES   BASED   UPON   DESTRUCTIVE    DISTILLATION. 

A. — Destructive  Distillation  of  Wood. 

I. — Raw  Materials 347,348 

1.  Composition  of  Wood,  347,  348.    2.  Effect  of  Heat  upon  Wood,  348. 

II. — Processes  of  Manufacture 349-355 

1.  Distillation  of  the  Wood,  349-351.  2.  Treatment  and  Purification  of 
the  Crude  Wood-vinegar,  351-353.  3.  Purification  of  the  Crude 
Wood-spirit,  353,  354.  4.  Treatment  of  the  Wood-tar,  354,  355. 

III.— Products 355,356 

1.  Pyroligneous  Acid  and  Products  therefrom,  355.  2.  Methyl  Alcohol 
and  Wood-spirit,  355.  3.  Acetone,  355,  356.  4.  Creosote,  356. 
5.  Paraffine,  356.  6.  Charcoal,  356. 

IV. — Analytical  Tests  and  Methods      356-358 

1.  Assay  of  Pyroligneous  Acid  and  Crude  Acetates,  356,  357.  2.  Deter- 
mination of  Methyl  Alcohol  in  Commercial  Wood-spirit,  357.  3. 
Determination  of  the  Acetone  in  Commercial  Wood-spirit,  357,  358. 
4.  Qualitative  Tests  for  Wood-tar  Creosote,  358 

B. — Destructive  Distillation  of  Coal. 
I. — Raw  Materials 358-362 

1.  Varieties  of  Coal,  358-360.  2.  Effects  of  Temperature  in  the  Dis- 
tillation of  Coal,  360-362. 

II. — Processes  of  Treatment 362-374 

1.  Gas-retort  Distillations  of  Coal,  362-365.  2.  Coke-oven  Distillation 
of  Coal,  365-368.  3.  Fractional  Separation  of  Crude  Coal-tar, 
368-371.  4.  Treatment  of  Ammoniacal  Liquor,  371-374. 

III.— Products 374-38i 

1.  First  Light  Oil,  374-377.  2.  Middle  Oil,  377,  378.  3.  Creosote  Oil 
(or  Heavy  Oil),  378,  379.  4.  Anthracene  Oil,  379-381.  5.  Pitch, 
381. 

IV.— Analytical  Tests  and  Methods 381-387 

1.  Valuation  of  Tar  Samples,  381,  382.  2.  Special  Tests  for  Tar  Con- 
stituents, 382-386.  3.  Valuation  of  Ammonia-liquor,  386.  4. 
Analysis  of  Illuminating  Gas,  386,  387. 

V. — Bibliography  and  Statistics  of  Destructive  Distillation  Industries  .    .    387-390 

CHAPTEK  XII. 

THE   ARTIFICIAL    COLORING   MATTERS. 

I. — Raw  Materials 391-405 

1.  Hydrocarbons,  391-394.  2.  Halogen  Derivatives,  394-396.  3. 
Nitro-  Derivatives,  396-398.  4.  Amine  Derivatives,  398-400.  5. 
Phenol  Derivatives,  400,  401.  6.  Sulpho- Acids,  401,  402.  7.  Pyri- 
dine  and  Quinoline  Bases,  402,  403.  8.  Diazo-  Compounds,  403,  404. 
9.  Aromatic  Acids  and  Aldehydes,  404.  10.  Ketones  and  Deriva- 
tives (Anthraquinone),  404,  405. 

II. — Processes  of  Manufacture 405-411 

,  1.  Of  Nitrobenzene  and  Aniline,  405-407.  2.  Of  Phenols,  Naphthols, 
etc.,  407,  408.  3.  Of  Aromatic  Acids  and  Phthaleins,  408,  409. 
4.  Of  Anthraquinone  and  Alizarin,  409,  410.  5.  Of  Quinoline 
and  Acridine,  410.  6.  Sulphonating,  410.  7.  Diazotizing,  410, 
411. 


TABLE   OF   CONTENTS.  xv 

PAGES 

III.— Products 411-422 

1.  Aniline  or  Amine  Dye-colors,  412,  413.  2.  Phenol  Dye-colors,  414, 
415.  3.  Nitroso  and  Oxyazine  Colors,  415,  416.  4.  Azo  Dye- 
colors,  416-419.  5.  Quinoline  and  Acridine  Dyes,  419,  420.  6. 
Artificial  Indigo,  420.  7.  Oxyketone  Colors,  420-422.  8.  Dyes 
of  Unknown  Constitution,  422. 

IV. — Analytical  Tests  and  Methods 422-438 

1.  Fastness  of  Colors  to  Light  and  Soap,  422.  2.  Comparative  Dye- 
trials,  422-424.  3.  Identification  of  Coal-tar  Dyes,  424-426.  4. 
Chemical  Analysis  of  Commercial  Dyes,  427,  428.  5.  Examina^ 
tionof  Dyed  Fibres,  428-438. 

V.— Bibliography  and  Statistics 439,44° 


CHAPTER  XIII. 

NATURAL    DYE-COLORS. 

I. — Raw  Materials 441-449 

A.  Red  Dyes,    441-444.      B.  Yellow  Dyes,  444-446.      C.  Blue  Dyes, 
446-448.     D.  Green  Dyes,  448,  449.     E.  Brown  Dyes,  449. 

II. — Processes  of  Treatment 449-456 

1.  Cutting  of  Dye-woods,  449.  2.  Fermentation  or  Curing  of  Dye- 
woods,  449,  450.  3.  Manufacture  of  Dye-wood  Extracts,  451-454. 
4.  Miscellaneous  Processes,  454-456 

III. — Products 456-462 

1.  From  Red  Dyestuifs,  456-458.  2.  From  Yellow  Dyestuffs,  458,  459. 
3.  From  Blue  Dyestuifs,  459-462.  4.  From  Brown  Dyes,  462. 

IV. — Analytical  Tests  and  Methods 462-469 

1.  For  Dye-woods,  462.  2.  For  Dye-wood  and  other  Extracts,  462-465. 
3.  For  Cochineal,  465,  466.  4.  For  Indigo  and  its  Preparations, 
466-469. 

V. — Bibliography  and  Statistics 469-471 


CHAPTER  XIV. 

BLEACHING,    DYEING,    AND   TEXTILE   PRINTING. 

I. — Preliminary  Treatment 472 

II. — Bleaching 472-478 

1.  For  Cotton,  472-476.     2.  For  Linen,  476,  477.     3.  For  Jute,  477. 
4.  For  Wool,  477,  478.     5.  For  Silk,  478 

III. — Bleaching  Agents  and  Assistants 478,479 

IV. — Mordants  employed  in  Dyeing  and  Printing 480-483 

1.  Mordants   of  Mineral   Origin,    480-482.     2.  Mordants   of  Organic 
Origin,  482,  483. 

V. — Dyeing 483-492 

1.  Cotton-dyeing,    484-488.      2.  Linen-dyeing,    488,    489.      3.  Jute- 
dyeing,  489.     4.  Wool-dyeing,  489-491.     5.  Silk-dyeing,  491,  492. 

VI. — Printing  Textile  Fabrics 492-502 

VII. — Bibliography 502, 503 


xvi  TABLE  OF   CONTENTS, 

APPENDIX 


I. — The  Metric  System 505,  506 

II. — Tables  for  Determination  of  Temperature    .    .  • 506-509 

Relations  between   Thermometers,    506.      Thermometric   Equivalents, 
507-509. 

III. — Specific  Gravity  Tables 510-521 

1.  Baume's  Scale  for  Liquids  Lighter  than  Water,  510.  2.  Baume  and 
Beck's  Scales  for  Liquids  Heavier  than  Water,  511.  3.  Twaddle's 
Scale  for  Liquids  Heavier  than  Water,  512.  4.  Comparison  of  the 
Twaddle  Scale  with  the  Eational  Baume  Scale,  513.  5.  Com- 
parison of  Gay-Lussac  Scale  with  Absolute  Specific  Gravity 
Figures,  514.  6.  Comparison  between  Specific  Gravity  Figures, 
Degree  Baume  and  Degree  Brix,  515-521 

IV. — Alcohol  Tables 522-527 

V. — Physical  and  Chemical  Constants  of  Fixed  Oils  and  Fats 528,  529 


LIST  OF  ILLUSTRATIONS. 


FIGURE  PAGE 

1.  Carburetting  Natural  Gas  ....  18 

2.  Crude  Oil  Still,  Cylindrical  Shape  20 

3.  Oil-still  with  Superheated  Steam  .  22 

4.  Still  for  Continuous  Distillation,  I.  23 

5.  Still  for   Continuous  Distillation, 

II 23 

6.  Commercial    Analysis    of    Crude 

Petroleum 33 

7.  Tagliabue's  Open-cup  Oil-tester    .  35 

8.  Say  bolt's  Open-cup  Oil  tester     .    .  36 

9.  Abel  Oil-testing  Apparatus    ...  37 

10.  Heumann  Oil-test  Apparatus     .    .  38 

11.  Stoddard  Flash-test  Apparatus  .    .  38 

12.  Tagliabue  Cold-test  Apparatus  .    .  39 

13.  Fischer's  Viscosimeter 40 

14.  Engler's  Viscosimeter 40 

15.  Thurston's  Lubricating  Oil-tester  .  41 

16.  Wilson's  Chromometer,  I.      ...  41 

17.  Wilson's  Chromometer,  II.    ...  41 

18.  Rendering  of  Tallow  by  Steam  .    .  54 

19.  Oil-seed  Mill 56 

20.  Oil-seed  Press 57 

21.  Autoclave  for  Saponifying  Fats    .  59 

22.  Distillation  of  Free  Fatty  Acids   .  60 

23.  Wilson    and   Gwynne   Apparatus 

for  Decomposing  Fats 60 

24.  Soap-coppers 63 

25.  Wooden  Soap-frames 65 

26.  Iron  Soap-frames 65 

27.  Soap-cutting  Machine 67 

28.  Crystallization     of     Solid     Fatty 

Acids 67 

29.  Stearic-acid  Press 68 

30.  Candle-moulding  Frame  .....  70 

31.  Soxhlet  Extractor 79 

32.  Thorn's  Extractor 79 

33.  Westphal  Specific  Gravity  Balance  80 

34.  Boiling  Linseed  Oil  over  Free  Fire  102 

35.  Boiling  Linseed  Oil  with  Steam    .  103 

36.  Distillation  of  Copal  and  Amber 

Resins 103 

37.  Vessel  for  Vulcanizing  Caoutchouc  107 

38.  Three-roll  Sugar-mill 126 

39.  Vacuum-pan 130 

40.  Yaryan  Evaporator 131 

41.  Yaryan      Evaporator      (sectional 

view) 132 

42.  Centrifugal  for  Sugars 133 

43.  Wetzel-pan 134 

44.  Sectional  View  of  Sugar  Refinery 

(full  page) 136 

45.  Centrifugal  for  Sugar-cones    ...  138 

46.  Diffusion  Battery— Elevation     .    .  139 

47.  Diffusion  Battery— Plan 140 


FIGURE  PAGE 

48.  Circular   Diffusion    Battery    (full 

page) 142 

49.  Filter-press  for  Sugar-scums  .    .    .  144 

50.  Osmogene 147 

61.  Steffen  Process  for  Molasses    ...  148 

52.  Char-kiln  for  Sugar  Refineries  .    .  149 

53.  Klusemann  Washer  (full  page)    .  151 

54.  Polariscope — Scheibler  Form     .    .  157 

55.  Pay  en's  Rendement  Method  ...  162 

56.  Scheibler's  Apparatus  for  Analysis 

of  Char 165 

57.  Hoffmann's  Converter  for  Glucose 

Manufacture 173 

58.  Maubre's    Converter  for   Glucose 

Manufacture 174 

59.  Lintner's  Pressure-flask  .        ...  179 

60.  Varieties  of  Yeast,  after  Hansen 

(full  page) 186 

61.  Effect  of  Temperature  upon  Fer- 

mentation    187 

62.  "Thick-mash"   Process  for  Beer 

(full  page) 193 

63.  Pasteurizing  Wine  in  Casks  ...  205 

64.  Apparatus  for  Determining  Alco- 

holic Strength 212 

65.  Coffey  Still  (full  page) 221 

66.  Derosne  Still 223 

67.  Savalle  Still 224 

68.  Element  in  Column  Still,  I.   ...  224 

69.  Element  in  Column  Still,  II.     .    .  224 

70.  Savalle  Rectifying  Column    ...  225 

71.  Aleurometer  of  Boland 238 

72.  Quick-vinegar  Process 242 

73.  Malt-vinegar  Cask 243 

74.  Laval  Cream  Separator,  I.     ...  255 

75.  Laval  Cream  Separator,  II.   ...  255 

76.  Fat-cutting  Machine  for  Oleomar- 

garine    257 

77.  Churning-machine    for    Oleomar- 

garine    258 

78.  Cotton    Fibre    magnified    Thirty 

Times 275 

79.  Cotton  Fibre  magnified  Two  Hun- 

dred Times     276 

80.  Sectional  View  of  Stems  and  Bast 

Fibres 276 

81.  Flax  Fibre  under  the  Microscope  .  277 

82.  Hemp  Fibre  under  the  Microscope  277 

83.  Jute  Fibre  under  the  Microscope  .  278 

84.  Manila  Hemp  under  the  Microscope  278 

85.  China-grass  under  the  Microscope  279 

86.  Vomiting  Boiler  for  Paper-makers  285 

87.  Hollander,  1 286 

88.  Hollander,  II.  (full  page)  ....  287 


XV111 


LIST   OF   DIAGRAMS. 


FIGURE  PAGE 

89.  Foudrinier  Machine  (full  page)  .  291 

90.  Nitration  of  Cellulose  in  Celluloid 

Manufacture 298 

91.  Wool  Fibre  under  the  Microscope  305 

92.  Alpaca  Hair  under  the  Microscope  307 

93.  Silk  Fibre  under  the  Microscope  .  308 

94.  Spinning  of  the  Silk  Cocoon    .    .  308 

95.  Silk-conditioning    .......  312 

96.  Magnified  Section  of  Ox-hide  .    .  320 

97.  Lime-pits    and    Liming    Process 

(full  page) .    .  326 

98.  Unhairing  Machines  and  Wash- 

ing Drums  (full  page)  ....  330 

99.  Revolving  Tumblers  for  Morocco- 

tanning     331 

100.  Steam-boiler  for  Glue  Manufac- 

ture      340 

101.  Distillation  of  Wood  from  Retorts  349 

102.  Distillation  of  Sawdust  from  Re- 

torts    351 

103.  Tar-condensers  of  Gas-works,  I.  .  364 

104.  Tar-condensers  of  Gas-works,  II.  364 

105.  Lime-purifiers  of  Gas-works     .    .  365 

106.  Simon-Carve's    Coke-oven    (full 

page) 367 


FIGURE  PAGE 

107.  Tar-still 369 

108.  Griineberg  and  Blum  Ammonia- 

still    374 

109.  Benzene  Rectification  Column     .  376 

110.  Naphthalene  Subliming-chamber  378 

111.  Anthracene-press 380 

112.  Sublimation  of  Anthracene  .    .    .  380 

113.  Manufacture  of  Nitrobenzene  .    .  406 

114.  Horizontal  Aniline-still     ....  407 

115.  Autoclave  for  Alizarin  Manufac- 

ture      409 

116.  Madder,  Indigo,  and  Archil    .    .  442 

117.  Cutting  of  Dye-woods 450 

118.  Extractor  for  Dye-woods  ....  451 

119.  Cell  of  Dye-wood  Extraction-bat- 

tery      452 

120.  Vacuum-pan  for  Dye-wood  Ex- 

tracts        453 

121.  Indigo  Grinding-mill 455 

122.  Madder  Bleach 473 

123.  Injector-kier 474 

124.  Steaming-chest    for    Turkey-red 

Yarn 488 

125.  Calico  Printing-machine  ....  493 

126.  Steaming  Indigo  Prints    ....  499 


LIST  OF  DIAGRAMS. 


General  View  of  the  Refining  of  Crude  Petroleum 21 

View  of  the  Practical  Utilization  of  a  Fat 61 

Outline  for  the  Analysis  of  Fatty  Oils 84 

Leed's  Scheme  for  Soap  Analysis 85 

General  View  of  the  Composition  of  the  Sugar-beet 123 

Outline  showing  the  Production  of  Sugar  from  the  Sugar-cane 127 

Outline  showing  the  Production  of  Sugar  from  the  Sugar-beet 143 

Outline  of  Tanning  Process  for  Sole-leather 328 

Qualitative  Tests  for  Tanning  Materials 337 

General  View  of  the  Treatment  of  Wood-tar 352 

General  View  of  the  Products  of  the  Distillation  of  Coal 362 

Scheme  for  the  Distillation  of  Coal-tar 372 

Tables  for  the  Identification  of  Coal-tar  Dyes 424-426 

Tables  for  the  Detection  of  Coloring  Matters  upon  the  Fibre 430-438 

Reactions  of  the  Most  Important  Natural  Dyestuffs 468 

Table  of  Artificial  Dye-colors  which  have  Replaced  or  Compete  with  Natural 

501,  502 


INDUSTRIAL  ORGANIC  CHEMISTRY. 


CHAPTER    I. 

PETROLEUM   AND   MINERAL   OIL   INDUSTRY. 


I.  Raw  Materials. 

THE  raw  materials  of  this  industry  are  hydrocarbons  and  products 
derived  from  them  by  alteration,  which  occur  associated  together  in  nature. 
They  may  be  gaseous,  liquid,  or  solid,  and  very  frequently  all  three  of  these 
physical  modifications  are  found  admixed  in  the  same  crude  material.  As, 
on  the  other  Land,  they  occur  at  times  separate  and  distinct,  they  will  be 
separately  noted. 

1.  NATURAL  GAS. — Under  this  name  is  generally  known  now  the 
mixture  of  inflammable  gases  that  is  found  issuing  from  the  earth  in 
various  localities.  While  it  is  chiefly  in  connection  with  the  boring  of 
wells  for  oil  or  salt,  or  as  a  constantly-forming  product  of  decomposition  in 
coal-mines,  that  it  has  been  obtained,  we  find  that  it  often  occurs  entirely 
independently  of  these.  "Burning  springs,"  as  they  have  been  termed, 
have  been  known  from  the  earliest  historical  times.  Those  of  Baku,  on 
the  Caspian  Sea,  are  supposed  to  have  been  burning  as  early  as  the  sixth 
century  before  Christ,  and  to  have  been  a  sacred  shrine  of  the  Persian  fire- 
worshippers.  The  Chinese  have  employed  natural  gas  for  centuries  in  their 
salt-mines  as  a  source  of  illumination.  In  the  United  States  it  was 
employed  already  in  1821,  at  Fredonia,  New  York,  as  a  source  of  illumi- 
nation, and  for  fifty  years  past  has  served  as  the  fuel  for  the  evaporation 
of  brine  at  the  salt- wells  of  the  Kanawha  Valley,  West  Virginia. 

In  chemical  composition,  natural  gas  is  relatively  uniform.  It  consists 
essentially  of  methane  (marsh-gas),  the  first  member  of  the  paraffin  series 
of  hydrocarbons,  which  may  be  accompanied  by  ethane,  propane,  and  the 
members  of  the  paraffin  series  next  following  methane.  Small  quantities  of 
hydrogen,  carbon  monoxide,  and  dioxide  have  been  found  to  be  present  at 
times,  while  nitrogen  is  apparently  an  invariable  impurity.  The  following 
table  gives  the  results  of  analyses  of  natural  gases,  made  in  1886,  by  Pro£ 
F.  C.  Phillips  for  the  Second  Geological  Survey  of  Pennsylvania.  The 
localities  chosen  are  all  in  Western  Pennsylvania,  with  the  exception  of 
Fredonia,  New  York,  which  is  introduced  because  of  its  historical  interest : 

13 


14 


PETEOLEUM  AND  MINERAL  OIL  INDUSTRY. 


& 

4 

A 

(., 

A 

-CJ* 

A 

A 

,* 

8 

8 

8 

Si2 

B~3 

$or 

6 

8| 

CONSTITUENTS. 

oj~  ° 

~fi 

§ 

§ 

>>^ 

S  5^ 

O<w> 

C    02 

•p  pH 

S  ^ 

..-  o> 

8 

—  -."pH 

W  K*» 

S  £ 

8 

C  § 

-C  <D 

II 

QJ  Q 

§V 

|| 

c  "* 

§i 

"i  ^ 

* 

m 

* 

& 

0} 

^    • 

tf 

m 

s° 

Paraffin  hydrocarbons 

90.05 

90.64 

90.38 

90.01 

95.42 

97.70 

90.09 

87.27 

84.26 

define  hydrocarbons 

Carbon  dioxide  .    .    . 

0.41 

6.30 

0.21 

0.20 

0.05 

0.20 

Trace. 

0.41 

0.44 

Hydrogen   

002 

Oxygen  . 

Trace 

Trace 

Trace 

Trace 

Trace 

Trace 

Trace 

Trace 

Nitrogen 

9  54 

9  06 

9  41 

9  79 

4  51 

2  02 

9  91 

12  32 

1  ^  30 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

The  paraffins  contained  in  these  gases  have  the  following  composition 

by  weight  : 

Carbon                    .    . 

78  14 

76  69 

76  52 

76  77 

77  11 

74  96 

76  42 

76  48 

76  68 

Hvdroeren  . 

21  86 

23  31 

23  48 

23  23 

22  89 

25  04 

23  58 

23  52 

23  32 

100.00 

100.00 

100.00 

10000 

100.00 

100.00 

100.00 

100.00 

100.00 

With  these  may  be  compared  the  natural  gas  from  two  important  petro- 
leum-yielding localities  in  Europe,  viz.,  Pechelbronn,  in  Alsace,  and  Baku, 
on  the  Caspian. 


Pechelbronn 

Pechelbronn 

Pechelbronn 

Baku 

Baku 

I. 

II. 

III. 

I. 

II. 

(Engler.) 

(Engler.) 

(Engler.) 

(Schmidt.) 

(Schmidt.) 

Methane  .    .    . 

73.6 

68.2 

77.3 

92.49 

93.09 

Olefines     .    .    . 

4.0 

3.4 

4.8 

4.11 

3.26 

Carbon  dioxide 

2.2 

2.9 

3.6 

0.93 

2.18 

Carbon  monoxide 

3.0 

3.7 

3.4 

Hydrogen     .    . 

.    . 

.    . 

6.34 

6.98 

Oxygen     .    .    . 

. 

4.3 

2.6 

.    . 

Nitrogen  .    .    . 

17.2 

16.9 

9.0 

2.13 

6.49 

100.00 

99.6 

100.10 

100.00 

100.00 

2.  CRUDE  PETROLEUM  (syn.  Erdoel,  Naphtha,  etc.). — Under  this 
heading  is  included  the  liquid  product  which  is  obtained  so  abundantly  in 
various  parts  of  the  earth,  either  issuing  from  the  ground  naturally  or 
gotten  by  the  boring  of  wells  through  the  overlaying  rocks  to  the  oil- 
bearing  strata.  The  oldest  and  so  far  the  most  important  petroleum  district 
of  the  world  is  the  Appalachian  field  of  Western  Pennsylvania,  extending 
from  Alleghany  County,  New  York,  through  Pennsylvania,  southwesterly 
into  West  Virginia  and  Eastern  Ohio.  While  the  oils  found  in  this  district 
may  differ  considerably  in  gravity,  color,  and  undoubtedly  in  chemical 
composition,  the  differences  are  not  fundamental,  and  with  certain  special 
exceptions  the  crude  oils  from  various  localities  are  all  brought  together  by 


RAW   MATERIALS.  15 

the  pipe-lines  and  become  mixed  before  going  to  the  refineries.  None  of 
these  Pennsylvania  or  West  Virginia  oils  contain  any  appreciable  amount  of 
sulphur  or  other  impurity  which  would  require  a  modification  of  the  general 
refining  methods.  The  heavy  oils  of  Franklin  and  Smith's  Ferry,  Pennsyl- 
vania, and  some  few  other  localities  are  so  valuable  for  the  manufacture  of 
lubricating  oils  that  they  are  collected  and  worked  separately.  The  Penn- 
sylvania crude  oil  has  in  general  a  dark  greenish-black  color,  appearing 
claret-red  by  transmitted  light,  and  varies  ordinarily  in  specific  gravity 
from  0.782  to  0.850,  or,  as  it  is  frequently  expressed,  from  49°  B.  to  34°-B. 
Exceptions  to  this  are  the  Washington  County  amber  oil,  the  light-colored 
Smith's  Ferry  oil,  and  some  other  natural  yellow  or  amber  oils.  In  chemi- 
cal composition  it  is  essentially  composed  of  hydrocarbons  of  the  paraffin 
series  CnH2a-t-2,  the  gaseous  and  the  solid  members  of  the  series  being  alike 
held  dissolved  in  the  liquid  ones,  and  smaller  amounts  of  the  hydrocarbons 
of  the  olefine  series  CnH2a,  and  the  benzene  series  CnH2n  _  6.  According  to 
Markownikoif,  Pennsylvania  petroleum  also  contains  hydrocarbons  of  a 
series,  CnH2a,  which  he  terms  "  naphthenes,"  which  are  probably  hydrogen 
addition  compounds  of  the  aromatic  series.  Within  recent  years  another 
important  field  has  developed,  viz.,  Ohio,  which  includes  the  two  distinct 
districts,  the  Lima  oil  district  and  the  Macksburg  district.  The  former 
is  by  far  the  more  important,  but  the  product  is  peculiar  in  that  it  contains 
sulphur,  and  has  an  offensive  odor  similar  to  Canadian  crude  oil.  Careful 
analyses  made  in  the  author's  laboratory  have  shown  that  it  contains  on  an 
average  0.42  per  cent,  of  sulphur,  combined  in  relatively  stable  forms  not 
decomposed  by  simple  distillation.*  Reference  will  be  made  to  it  in  speak- 
ing of  refining  methods.  Within  recent  years  the  extension  of  the  Lima 
(or  Trenton  Limestone)  oil-field  westerly  into  Indiana  has  added  to  the 
production  of  this  grade  of  oil.  The  most  important  localities  in  the 
United  States,  outside  of  the  Pennsylvania  and  Ohio  oil-fields,  are  Texas, 
Colorado,  and  California,  in  which  latter  State  a  blackish  petroleum  of 
rather  heavier  consistency  than  Pennsylvania  petroleum  is  found  quite 
abundantly.  This  California  petroleum  is  peculiar  in  containing  nitrog- 
enous bases  of  the  pyridine  and  quinoline  groups,  and  in  leaving,  instead 
of  paraffine,  an  asphaltic  base  or  residuum. 

Closely  related  to  the  Pennsylvania  and  New  York  oil-fields  is  the  oil 
district  of  Canada.  This  is  in  the  neighborhood  of  Enniskillen,  in  the 
western  section  of  the  province  of  Ontario.  The  Canadian  petroleum, 
however,  is  distinctly  different  from  that  of  Pennsylvania.  It  is  darker 
in  color,  heavier  in  gravity,  and  is  of  a  very  offensive  odor  on  account  of 
sulphur  impurity,  and  is  therefore  more  difficult  and  expensive  to  refine. 
As  before  stated,  it  finds  a  counterpart  in  the  oil  of  Lima,  Ohio. 

Second  in  importance  to  the  Pennsylvania  oil-fields,  and  even  more  pro- 
lific in  the  yield  of  individual  wells,  is  the  Russian  petroleum  district  of 
Baku,  on  the  Caspian.  For  detailed  accounts  of  the  extraordinary  pro- 
duction of  these  wells,  the  reader  is  referred  to  Boverton  Redwood's  "  Pe- 
troleum and  its  Products,"  vol.  i.  p.  26,  or  to  Engler's  articles  in  Ding- 
ler's  Polytechnisches  Journal,  Bd.  cclx  and  cclxi.  The  Russian  petroleum 
has  a  higher  gravity  than  the  American,  averaging  0.873,  or  31°  B.,  and 
has  been  found  to  be  entirely  different  in  its  chemical  composition,  consist- 

*  Mabery  (Am.  Chem.  Jour.,  April,  1891)  has  identified  in  Ohio  petroleum  methyl, 
ethyl,  normal  propyl,  iso-  and  normal  butyl,  pentyl,  ethyl-pentyl,  and  hexyl  sulphides. 


16  PETROLEUM  AND  MINERAL  OIL  INDUSTRY. 

ing  for  the  most  part  of  hydrocarbons  of  the  series  CnH2n,  isomeric  with 
the  olefine  series,  and  called  "  naphthenes."  As  will  be  seen  later,  this  dif- 
ference in  chemical  composition  involves  a  difference  in  the  refining  results. 

The  most  important  of  the  other  European  petroleum-fields  are  those 
of  Galicia,  which  produce  a  variety  of  oils,  both  light  and  heavy,  either 
accompanying  or  independent  of  the  ozokerite  of  the  region,  those  of 
Hanover,  which  yield  thick  oils,  varying  in  specific  gravity  from  .862  to 
.910,  and  those  of  Alsace,  which  also  yield  oils  predominantly  heavy,  and 
used  chiefly  for  lubricants. 

The  Asiatic  petroleum-fields  are  those  of  Burmah,  which  have  long 
been  known  to  be  very  rich,  and  which,  under  British  control,  will  now  be 
developed,  and  those  of  Rangoon,  in  India,  the  oils  from  which  are  thick 
and  heavy,  yielding  much  lubricating  oil  and  paraffin,  and  those  of  Japan. 

3.  CRUDE  PARAFFINE. — Under  this  head  may  be  understood  the  more 
or  less  compact  solid  material  which  often  accompanies  crude  petroleum,  is 
deposited  from  it  on  standing,  and  in  some  cases  is  found  in  extensive  deposits 
independently  of  it.     Thus,  a  deposit  of  buttery  consistency  separates  from 
some  crude  oils,  such  as  Bradford  oil,  and  adheres  to  the  pumping  machinery 
and  derrick,  forming  a  crust  which  has  to  be  scraped  off  from  time  to 
time.     The  same  oils  deposit  crude  paraffine  in  the  pipe-lines,  necessitating 
a  periodical   scraping   of  the   interior  of  the   pipe-lines.      Much  of  the 
deposit  which  accumulates  in  the  storage-tanks  of  crude  oil  is  of  the  same 
material. 

More  important,  however,  is  the  occurrence  of  solid  native  paraffine, 
under  the  name  of  "ozokerite,"  or  earth-wax.  The  best-known  locality 
for  this  native  paraffine  is  Boryslaw,  in  Eastern  Galicia,  although  it  is  found 
also  in  the  Caucasian  oil  district,  and  in  Persia  under  the  name  of  "  neft- 
gil,"  and  a  few  years  ago  was  found  in  Southern  Utah,  in  the  United  States. 
In  color  it  varies  from  dark  green  to  black,  and  possesses  a  lamellar  or 
conchoidal  fracture,  according  to  the  variety.  It  fuses  between  56°  and 
74°  C.,  or  even  higher.  In  chemical  composition  it  does  not  differ  much 
from  the  separated  paraffine  of  petroleum  oils. 

4.  BITUMEN  AND  ASPHALT. — We  may  have  liquid  bitumens,  usually 
called  malthas,  and  solid  bitumens,  called  asphalts.    Both  may  be  considered 
as  alteration  products  of  petroleum  hydrocarbons  resulting  from  evaporation 
and  oxidation. 

Maltha  (or  mineral  tar)  was  first  found  at  Bechelbronn,  in  Alsace,  and 
was  studied  by  Boussingault,  who  described  it  as  a  viscid,  tarry  liquid  of 
bituminous  odor  and  a  specific  gravity  of  .966.  It  contains  besides  hydro- 
carbons both  sulphur  and  nitrogen. 

In  the  United  States  malthas  are  found  in  California  in  Kern,  Ventura, 
and  Santa  Barbara  Counties,  as  well  as  in  Utah,  Kentucky,  Tennessee,  and 
Texas.  Those  from  California,  which  have  been  chemically  examined,  in- 
variably contain  some  nitrogen  present  in  the  form  of  basic  hydrocarbons. 
They  also  contain  some  water  and  dissolved  gases. 

The  purest  of  the  solid  bitumens  are  known  sometimes  as  "glance 
pitch'7  or  "  gum  asphaltum."  Prominent  among  them  is  gilsonite,  which 
is  found  in  the  Uintah  Indian  reservation  in  Wasatch  and  Uintah  Counties, 
Utah.  The  purity  of  this  product  (some  ninety  to  ninety-eight  per  cent, 
soluble  in  carbon  disulphide)  is  such  that  it  finds  large  application  in  the 
manufacture  of  varnishes  and  insulating  compounds,  the  production  being 
some  three  thousand  tons  annually. 


PEOCESSES  OF  TREATMENT. 


17 


Of  solid  asphalts,  those  of  greatest  commercial  importance  are  the 
Trinidad  Lake  asphalt  from  the  Island  of  Trinidad  in  the  West  Indies 
and  the  Bermudez  asphalt  from  Venezuela,  South  America.  The  first  of 
these  contains  in  the  crude  state  39.83  per  cent,  of  bitumen,  33.99  per 
cent,  of  earthy  matter,  9.31  per  cent,  of  vegetable  non-bituminous  matter, 
and  16.87  per  cent,  of  water.  After  refining  the  water  is  eliminated  and  the 
bitumen  is  raised  to  about  sixty  per  cent.  The  Bermudez  asphalt  contains 
but  2.63  per  cent,  of  mineral  matter  and  over  ninety  per  cent,  of  bitumen. 
The  solid  asphalts  of  California  contain  from  sixty  to  ninety  per  cent,  of 
bitumen,  while  the  mineral  matter  in  most  cases  is  a  very  pure  silica,  or  in 
some  cases  infusorial  earth.  Other  solid  asphalts,  but  less  valuable,  are 
those  of  Cuba  and  Syria,  containing  some  seventy-five  per-oent.  -of  a  hard, 
brittle  bitumen. 

Very  important  also  are  the  bituminous  limestones  or  "rock  asphalts" 
of  Europe.  Among  these  may  be  mentioned  those  of  Seyssel,  France,  Val 
de  Travers  in  the  canton  of  Neufchatel,  Switzerland,  Ragusa  in  Sicily,  and 
Limmer  and  Vorwohle  in  Germany.  These  contain  from  five  and  three- 
tenths  to  fourteen  per  cent,  of  bitumen,  and  about  eighty- six  to  ninety  per 
cent,  of  carbonate  of  lime,  and  as  they  are  largely  used  both  in  this  country 
and  in  Europe  in  the  manufacture  of  asphaltic  mixtures  or  mastics,  a  table 
showing  their  exact  composition  is  given  : 


Seyssel, 
France. 

Valde 
Travers, 
Switzerland. 

Ragusa, 
Sicily. 

Limmer, 
Germany. 

Vorwohle, 
Germany. 

Bitumen  -  . 

8  15 

10.15 

8.92 

14.30 

5.37 

Calcium  carbonate  .  . 
Magnesium  carbonate  . 
Clay  and  oxide  of  iron  . 
Sand  

91.30 
.10 
.15 

88.40 
.30 
.25 

88.21 
.96 
.91 
.60 

67.00 
17.52 

90.80 
.35 
.59 
2.55 

.10 

.45 

Loss  .... 

.20 

.45 

.40 

1.18 

.34 

100.00 

100.00 

100.00 

100.00 

100.00 

In  the  United  States  the  most  important  occurrence  of  bituminous 
limestone  is  that  of  Uvalde  County,  Texas,  from  which  is  obtained  .the 
product  known  as  "  litho-carbon,"  used  in  varnish-making  and  for  insu- 
lating purposes. 

Related  to  the  natural  asphalts  are  also  such  minerals  as  Albertite,  from 
the  Albert  mines  in  New  Brunswick,  and  the  Ritchie  mineral  from  Ritchie 
County,  West  Virginia. 

The  Torbane  mineral,  from  Bathgate,  Scotland,  and  Boghead  coal, 
together  with  bituminous  shales,  also  should  be  noted  here.  They  form  the 
crude  material  for  the  Scotch  paraffine  distillation. 


n.  Processes  of  Treatment. 

1.  OF  NATURAL  GAS. — If  we  refer  to  the  composition  of  natural  gas,  as 
already  stated,  it  will  be  seen  that  it  is  largely  made  up  of  methane  and  its 
homologues,  with  some  nitrogen  as  impurity.  The  olefines,  or  "  illumi- 
nating hydrocarbons"  of  ordinary  coal-gas,  are  practically  absent  in  most 

2 


18 


PETROLEUM  AND  MINERAL  OIL  INDUSTRY. 


PIG.  1. 


cases.  This  at  once  indicates  quite  clearly  the  value  of  natural  gas  as  a 
fuel  and  its  lack  of  value  in  the  natural  state  for  illuminating  purposes. 
But  that  it  can  be  readily  converted  into  an  excellent  illuminating  gas  has 
been  shown,  and  in  Western  Pennsylvania,  where  natural  gas  is  abundant, 
it  is  being  used  for  illumination  as  well  as  for  fuel.  To  illustrate  the  treat- 
ment that  is  necessary  for  the  purpose  we  may  describe  the  McKay  and 
Critchlow  process,  which  has  proven  quite  successful  in  practice.  The 
apparatus,  as  shown  in  Fig.  1,  consists  essentially  like  the  water-gas  gen- 
erators of  a  combustion-chamber 
filled  with  coal  brought  to  a 
white  heat  by  an  air-blast  and 
a  fixing-chamber  above  filled 
with  fire-brick,  where  the  gas- 
eous products  of  the  first  reac- 
tion combine  with  oil  vapors  to 
form  a  permanent  illuminating 
gas.  The  procedure  is  as  follows : 
The  fuel  having  been  rendered 
thoroughly  incandescent,  and  the 
fire-brick  structure  having  been 
heated  to  a  light  orange  tint,  the 
air-blast  is  shut  off,  the  lid  of 
the  cupola  closed,  and  the  gas 
outlet  opened.  Natural  gas  is 
then  introduced  into  the  ash-pit 
and  forced  up  and  through  the 
incandescent  fuel-bed,  depositing 
its  carbon  on  the  surfaces  of  the 
fuel  as  decomposition  is  effected, 
and  hydrogen  gas  is  thus  liber- 
ated, which,  passing  up  through 
the  open  chamber,  meets  the 
vapors  of  the  hydrocarbon,1- 
which  is  projected  into  the 
chambers  by  means  of  a  steam- 
or  gas-injector.  All  of  these 
products  of  decomposition  pass- 
ing together  into  the  upper  or 
fixing  chamber,  a  part  of  the 
hydrogen  unites  with  the  heavy 
hydrocarbons,  producing  the 
lighter  hydrocarbons,  while  an 
intimate  mixture  of  all  the  gases  is  effected,  forming  a  completely  perma- 
nent illuminating  gas,  which  passes  off  through  the  water-seal,  condensers, 
scrubbers,  and  purifiers  to  the  holder  in  the  ordinary  way.  Natural  gas  is 
used  quite  largely  now  with  Welsbach  burners,  and  an  excellent  illumina- 
tion is  thus  obtained. 

Natural  gas  is  also  burned  for  the  production  of  a  very  pure  grade  of 
lamp-black.  This  manufacture,  first  carried  out  at  Gambier,  Ohio,  is  now 
introduced  at  various  places  in  the  oil  regions  of  Pennsylvania.  The  gas 
is  burned  from  rows  of  burners  placed  in  such  position  that  the  flame  im- 
pinges upon  slate  or  metallic  slabs  or  revolving  cylinders,  and  there  deposits 


PROCESSES  OF  TREATMENT. 


19 


its  carbon.  In  one  building  at  Gambier,  eighteen  hundred  burners  have 
been  used,  consuming  two  hundred  and  seventy-five  thousand  cubic  feet  of 
gas  per  twenty-four  hours. 

2.  OF  CRUDE  PETROLEUM. — As  petroleum  has  been  shown  to  be  a 
mixture  of  hydrocarbons  of  different  volatility,  the  first  operation  would 
naturally  be  to  effect  a  partial  separation  of  these  hydrocarbons  by  a 
process  of  fractional  distillation.  But,  in  fact,  simpler  lines  of  treatment 
were  first  tried.  It  was  found  that  crude  oils  spread  out  over  warm  water 
in  tanks  and  exposed  to  the  sun  were  much  improved  in  gravity  and  con- 
sistency. This  process  was  chiefly  employed  for  the  production  of  lubri- 
cating oils,  and  the  products  were  called  "  sunned  oils."  This  was  followed 
by  the  application  of  methods  of  partial  evaporation  or  concentration  in 
stills,  either  by  direct  application  of  heat  or  by  the  use  of  steam  coils,  care- 
fully avoiding  overheating.  The  products  are  called  "  reduced  oils,"  and 
form  the  best  material  for  the  manufacture  of  high-grade  lubricating  oils. 
They  will  be  referred  to  again.  The  process  to  which  the  great  bulk  of 
crude  petroleum  is  submitted,  howrever,  is  that  of  fractional  distillation 
continued  to  the  eventual  coking  of  the  residue.  As  the  most  valuable 
of  the  several  distillates  is  that  which  is  to  be  used  as  illuminating  oil,  the 
percentage  of  that  distillate  obtainable  is  an  important  item  in  an  oil 
refinery.  A  normally-conducted  fractional  distillation  of  Pennsylvania 
petroleum  will  give  from  thirty-five  to  fifty-five  per  cent,  of  oil  suitable  for 
illuminating  purposes,  and  from  twenty  to  thirty  per  cent,  of  lubricating 
oils.  About  1865,  however,  it  was  found  that  if  during  the  distillation 
the  heavy  vapors  were  made  to  drop  back  upon  the  hot  oil  in  the  still  they 
became  superheated  and  were  decomposed.  This  process  of  destructive  dis- 

The  Results  of  a  Normal  Distillation  of  One  Hundred  Cubic  Centimetres  of  Crude  Oils  are 

thus  given  by  Engler : 


CRUDE  OIL  FROM 

Sp.  gr.  at 
17°  C. 

Began 
to  boil. 

Came  over 
under  150°  C. 

Between  150°  C. 
and  300°  C. 

Over  300°  C. 

Pennsylvania  (I.) 
Pennsylvania  (II.)   . 
Galicia  (Sloboda)  .    . 
Baku  (Bibieybat)  .    . 
Baku  (Balakhani)     . 
Alsace  (Pechelbronn) 
Hanover  (Oelheim) 

0.8175 
0.8010 
0.8235 
0.8590 
0.8710 
0.9075 
0.8990 

82°  C. 
74°  C. 
90°  C. 
91°  C. 
105°  C. 
135°  C. 
170°  C. 

21     per  cent. 
31.5  percent. 
26.  5  per  cent. 
23     per  cent. 
8.5  per  cent. 
3     per  cent. 

38.25  per  cent. 
35       per  cent. 
47       per  cent. 
38       per  cent. 
39.5    per  cent. 
50       per  cent. 
32       per  cent. 

40.75  per  cent. 
33.5    per  cent. 
26.5    per  cent. 
39       per  cent. 
52       per  cent. 
47       per  cent. 
68       per  cent. 

The  Commercial  Results  usually  obtained,  on  the  other  hand,  are  thus  stated  by  the  same 
Authority  (Wagner's  Jahresbericht,  1886,  p.  1077). 


CRUDE  OIL  FROM 

Benzine  and 
volatile  oils. 

Burning  oil, 
first  quality. 

Burning  oil, 
second  quality. 

Residuum. 

Pennsylvania            

10  to  20 

60  t 

o  75 

5  to  10 

Galicia                   

3  to  6 

55  t 

o  65 

30  to  40 

Alsace                   

35  t 

o  45 

55  to  60 

4 

60  t 

o  70 

25  to  35 

Baku  (Bibieybat)     

10.5 

40 

13.5 

36 

Baku  (Balakhani)    

5  to  6 

27  to  33 

5  to  6 

50  to  60 

tillation  or  "  cracking"  allowed  of  a  notable  increase  of  the  illuminating 
oil  fraction  at  the  expense  of  the  lubricating  oil.     So  at  present   some 


20  PETROLEUM  AND  MINERAL  OIL  INDUSTRY. 

seventy-five  to  eighty  per  cent,  of  burning  oil  is  obtained,  while  the  re- 
siduum from  which  the  lubricating  oil  is  gotten  is  reduced  to  six  per  cent. 

A  general  outline  of  the  petroleum  refining  process  as  at  present  con- 
ducted is  presented  in  tabular  form  on  the  accompanying  diagram. 

The  process  is  generally  divided  into  two  quite  distinct  parts.  The 
benzine  and  burning  oil  distillate  are  run  from  the  same  still,  when  the 
fluid  residuum  is  transferred  to  what  are  usually  called  "  tar-stills,"  in  which 
the  rest  of  the  distilling  operation  is  conducted. 

FIG.  2. 


Lateral  vertical  section  of  cylindrical  still. 


Transverse  vertical  section  of  cylindrical  still. 


The  crude-oil  stills  are  of  two  forms,  the  cylindrical  still,  as  illus- 
trated in  section  in  Fig.  2,  and  the  "  cheese-box"  still,  although  the  latter  is 
little  used  now.  The  former  consists  of  a  cylinder  of  boiler-plate,  the 
lower  half  being  generally  of  steel,  thirty  feet  in  length  by  twelve  feet  six 
inches  in  diameter.  This  still  is  set  horizontally,  as  shown  in  the  sectional 
view,  in  a  furnace  of  brick-work,  usually  so  constructed  that  the  upper 
part  of  the  still  is  exposed  to  the  air.  The  "  cheese-box"  still  has  a  body 
and  dome-shaped  top  of  boiler-plate  and  a  double  curved  bottom  of  steel 
plate.  It  is  thirty  feet  in  diameter  and  nine  feet  in  height,  and  is  set  on  a 
series  of  brick  arches.  The  working  charge  of  the  cylindrical  stills  is 


PROCESSES  OF  TREATMENT. 


21 


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5'    O 

0.1  E| 


r 


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•If  Hi 

8  |g  18 

5=*^  a  0,3. 
IgJSo 


ing-  oil 
to  the 


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on?  to 


VUrftftt 

S5811 


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Ip|| 
t^l 
I  ?s? 

3     Sgg    » 
•I     ISg    |. 

d 

8 


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g  «'2 


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O 

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o 

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22 


PETROLEUM   AND   MINERAL   OIL  INDUSTRY. 


about  seven  hundred  barrels  of  crude  oil,  although  occasionally  stills  of 
one  thousand  barrels'  capacity  have  been  used.  The  still  is  usually  pro- 
vided with  coils  of  steam-pipes,  both  closed  and  perforated.  The  steam, 
issuing  in  jets  from  the  perforated  pipe,  has  been  found  to  facilitate  dis- 
tillation by  carrying  over  mechanically  the  oil  vapors. 

The  condensing  apparatus  varies  somewhat  in  the  details  of  its  con- 
struction, but  consists  essentially  of  long  coils  of  pipe  immersed  in  tanks, 
through  which  water  is  kept  flowing.  The  terminal  portions  of  the  con- 
densing pipes  all  converge  and  enter  the  receiving  house  within  a  few 
inches  of  each  other.  Near  the  extremity  of  each  a  trap  in  the  pipe  is 
made  for  the  purpose  of  carrying  away  the  uncondensable  vapor.  This 
may  be  allowed  to  escape,  or  is  burned  underneath  the  boilers  or  stills, 
effecting  thereby  a  large  saving  in  fuel.  The  condensing  pipes  generally 
deliver  into  box-like  receptacles,  with  plate-glass  sides,  through  which  the 
running  of  the  distillate  can  be  observed,  and  from  which  test  portions  can 
be  taken  from  time  to  time  for  the  proper  control  of  the  process. 

The  tar-stills  are  usually  of  steel,  cylindrical  in  shape,  holding  about 
two  hundred  and  sixty  barrels,  and  are  set  in  groups  of  two  or  more,  sur- 
rounded by  brick-work.  They  are  either  upright  or  horizontally  placed, 
usage  inclining  now  to  the  latter  position.  Vacuum-stills  have  been  and 
are  still  used  to  some  extent,  especially  in  the  preparation  of  reduced  oils 
for  the  manufacture  of  lubricants  and  products  like  vaseline.  Of  course, 
the  evaporation  in  these  stills  takes  place  rapidly,  and  at  the  lowest  temper- 
ature possible,  insuring  a  fractional  distillation  and  not  a  decomposition. 
If  superheated  steam  be  used,  moreover,  instead  of  direct  firing,  it  is  pos- 
sible to  reduce  oils  to  26°  B.  without  any  production  of  pyrogenic  products. 
A  still  arranged  with  superheated  steam  is  shown  in  Fig.  3.  Continuous 

distillation  has  not 
proved  commercially 
successful  in  the 
United  States.  In 
Russia,  on  the  other 
hand,  continuous  dis- 
tillation has  been  emi- 
nently s  u  c  c  e  s  s  f  u  1, 
being  especially  suited 
to  Baku  petroleum,  as 
the  quantity  of  burn- 
ing oil  separated  being 
comparatively  small, 
the  residuum  is  not 
very  much  less  fluid 
than  the  crude  oil. 
The  stills,  each  of  the 
capacity  of  four  thou- 
sand four  hundred  gal- 
lons, are  arranged  in 
groups  or  series  of  not 
more  than  twenty-five, 
as  shown  in  Figs.  4  and  5,  one  of  which  is  a  front  view,  and  the  other  a  section, 
and  a  stream  of  oil  is  kept  continuously  flowing  through  the  entire  number. 
The  crude  oil,  entering  the  first  still,  parts  with  its  most  volatile  constituents ; 


PROCESSES   OF  TREATMENT. 


23 


FIG.  4. 


passing  into  the  next  still,  has  rather  less  volatile  hydrocarbons  distilled 
from  it ;  and,  finally,  flows  from  the  last  still  in  the  condition  of  residuum, 
which  in  Russia  is  termed  as- 
tatki,  or  masut.  The  several 
stills  are  maintained  at  tem- 
peratures corresponding  with 
the  boiling-points  of  the  prod- 
ucts to  be  volatilized.  Super- 
heated steam  is  used  for  all  the 
stills,  the  steam  being  deliv- 
ered partly  under  the  oil  and 
partly  above  the  level  of  the 
oil, — that  is,  in  the  vapor  space 
above.  The  fuel  used  under 
all  the  stills  in  Baku  is  petro- 
leum residuum,  or  astatki. 

To  recur,  now,  to  the  products  of  the  first  rough  distillation  of  crude 
oil,  the  first  fraction,  known  as  the  "  benzine  distillate/7  and  amounting 
usually  to  twelve  per  cent,  of  the  crude  oil,  is  redistilled  by  steam  heat  in 
cylindrical  stills,  holding  five  hundred  barrels,  and  is  sometimes  separated 
into  the  following  products:  cymogene,  100°  to  110°  B.  gravity;  rhigo- 
lene,  90°  to  100°  B.  gravity  ;  gasolene,  80°  to  90°  B.  gravity ;  naphtha, 
70°  to  76°  B.  gravity;  benzine,  62°  to  70°  B.  gravity. 

The  time  occupied  in  working  the  charge  is  about  forty-eight  hours. 
The  percentage  of  these  products  varies,  but,  as  a  rule,  amounts  to  about 
twenty-five  per  cent,  of  the  first  three  collectively,  rather  more  than  twenty- 
five  per  cent,  of  the  naphtha,  and  about  forty  per  cent,  of  the  benzine. 
The  deodorization  of  the  benzine  which  is  to  be  used  for  solvent  purposes 
in  pharmacy  or  the  arts  is  effected  somewhat  after  the  manner  to  be  described 
under  burning  oils  by  the  action  of  sulphuric  acid.  Only  the  proportion 
of  acid  used  is  much  smaller  and  the  agitation  is  effected  by  revolving 
paddles  instead  of  by  an  air-blast.  One-half  of  one  per  cent,  is  sufficient 

FIG.  5. 


in  this  case.  Other  processes  have  been  proposed  for  the  deodorization, 
such  as  the  use  of  mixtures  of  sulphuric  and  nitric  acids  with  alcohol, 
which  produce  ethereal  products  which  are  said  to  neutralize  and  destroy 
the  benzine  odor. 

The  treatment  of  the  illuminating  oil  fraction  is  a  more  important 


24  PETROLEUM  AND   MINERAL   OIL   INDUSTRY. 

process.  It  must  be  freed  from  the  empyreumatic  products  resulting  from 
the  distillation,  which  give  it  both  color  and  disagreeable  odor.  To  effect 
this  it  is  subjected  to  a  treatment  with  sulphuric  acid,  washing  with  water 
and  a  solution  of  caustic  soda.  This  operation  is  conducted  in  tall  cylin- 
drical tanks  of  wrought  iron,  lined  with  sheet-lead,  which  are  called  "  agi- 
tators." The  bottom  is  funnel-shaped,  terminating  »in  a  pipe  furnished 
with  a  stopcock  for  drawing  off  the  refuse  acid  and  soda  washings.  The 
distillate  to  be  treated  must  be  cooled  to  at  least  60°  F.,  and  before  the 
main  body  of  acid  is  added  for  the  treatment,  any  water  present  must  be 
carefully  withdrawn.  This  is  done  by  starting  the  agitation  of  the  oil  by 
the  air-pump  and  introducing  a  small  quantity  of  acid.  This  is  allowed 
to  settle,  and  withdrawn.  The  oil  is  now  agitated,  and  about  one-half  of 
the  charge  of  acid  is  introduced  gradually  from  above.  The  agitation  is 
now  to  be  continued  as  long  as  action  is  indicated  by  rise  of  temperature, 
when  the  dark  "  sludge  acid"  is  allowed  to  settle,  and  withdrawn.  The 
remaining  portion  of  acid  is  added,  and  a  second  thorough  agitation  takes 
place.  The  whole  charge  of  acid  needed  for  an  average  distillate  is  about 
one  and  one-half  to  two  per  cent.,  or  about  six  pounds  of  acid  to  the  barrel  of 
oil.  The  acid,  as  drawn  off,  is  dark-blue  or  reddish-brown  in  color,  and 
is  charged  with  the  sulpho-compounds  of  the  olefines,  while  free  sulphur 
dioxide  gas  is  present  in  abundance.  The  oil,  after  treatment,  consists  of 
the  paraffin  hydrocarbons  almost  freed  from  admixture  with  olefines.  In 
color  it  has  been  changed  from  brownish-yellow  to  a  very  light  straw  shade. 
The  oil  is  now  washed  with  water  introduced  through  a  perforated  pipe 
running  around  the  upper  circumference  of  the  tank.  This  water  perco- 
lates through  the  body  of  the  oil,  removes  the  acid,  and  is  allowed  to 
escape  in  a  constant  stream  from  the  bottom.  When  the  wash- water  shows 
no  appreciable  acid  taste  or  reaction,  the  washing  is  stopped,  and  about  one 
per  cent,  of  a  caustic  soda  solution  of  12°  B.  is  introduced,  and  the  oil  is 
again  agitated.  When  this  is  drawn  off,  the  oil  is  ready  for  the  settling 
tanks.  A  washing  with  water  after  the  soda  treatment  is  sometimes 
followed,  but  it  is  not  general.  A  washing  with  dilute  ammonia  is  also 
sometimes  used  to  remove  the  dissolved  sulpho-compounds.  The  settling 
tanks  are  shallow  tanks,  exposed  to  air  and  light  on  the  sides,  and  here  any 
water  contained  in  the  oil  settles  out,  and  the  oil  becomes  clear  and  brilliant. 
They  are  provided  with  steam-coils  for  gently  warming  the  oil  in  cold 
weather  to  facilitate  this  separation.  A  spraying  of  the  finished  oil  to  raise 
the  fire-test  by  volatilizing  a  small  quantity  of  the  lighter  hydrocarbon 
present  was  formerly  practised  at  this  stage,  but  exacter  control  of  the  dis- 
tillation has  rendered  it  no  longer  necessary. 

The  Lima  oil  and  Canadian  oil,  which,  as  before  stated,  contain  sulphur 
impurity,  cannot  be  refined  and  good  illuminating  oils  obtained  by  this  simple 
treatment  with  acid  and  alkali.  Various  methods  of  treatment  have  been 
proposed  and  patented  for  these  oils,  such  as  the  alternate  treatment  with 
litharge  and  caustic  soda,  distillation  over  finely-divided  copper  and  iron, 
but  the  method  finally  adopted  and  now  in  successful  use  is  to  distil  over 
a  mixture  of  oxides  of  copper  and  lead,  which  take  up  the  sulphur. 
The  oil  is  also  sold  for  fuel  purposes.  This  latter  utilization  has  been  one 
of  great  importance,  and  it  is  employed  in  all  classes  of  manufacturing 
establishments  with  great  success  aod  economy  as  a  substitute  for  solid  fuel. 
With  the  aid  of  injector  burners,  it  has  been  found  possible  to  use  it  in 
smelting  and  annealing  furnaces,  in  all  kinds  of  forges,  in  burning  brick, 


PROCESSES   OF   TREATMENT.  25 

tiles,  and  lime,  and  for  raising  steam  with  all  forms  of  boilers.  It  is  used 
in  these  burners  in  connection  with  either  steam  or  compressed  air. 

The  residuum  of  the  original  crude-oil  distillation  is,  as  was  said,  dis- 
tilled from  the  "  tar-stills."  The  first  runnings,  constituting  from  twenty 
to  twenty-five  per  cent.,  will  have  a  gravity  of  38°  B.,  and  are  returned  to 
the  crude-oil  tank  for  redistillation,  or  are  treated  and  purified  as  burning 
oil.  •  The  paraffine  oil  which  now  runs  over  may  be  caught  in  separate  lots 
as  it  deepens  in  color  and  increases  in  density,  or  it  may  be  all  received 
together  to  be  treated  in  the  paraffine  agitator  with  acid  and  punfied  for  the 
separation  of  paraffine  wax.  The  agitator  in  this  case  must  be  provided 
with  steam-pipes,  so  that  its  contents  can  be  kept  perfectly  liquid,  and  the 
charge  of  acid  is  larger,  amounting  to  three,  four,  or  even  five  per  cent. 
The  treatment  includes  the  usual  washing  with  water  and  soda  all  at  the 
proper  temperature.*  The  "  sludge"  becomes  quite  solid  on  standing,  and  is 
not  worked  over.  After  settling,  the  paraffine  oil  goes  to  the  chill-rooms, 
where,  by  the  aid  of  the  ammonia  refrigerating  machines  and  the  circula- 
tion of  cooled  brine,  the  whole  mass  is  brought  to  a  semi-solid  condition. 
This  is  pressed  between  bagging  by  hydraulic  pressure,  or  is  filter-pressed, 
and  the  refined  heavy  oil  which  drains  off  is  collected  as  lubricating  oil. 
Its  gravity  should  be  about  32°  B.,  fire-test,  325°  F.,  and  cold  test,  30°  F. 
The  pre-s-cake  may  be  broken  up,  melted,  and  recrystallized,  and  then 
submitted  to  still  greater  pressure  at  a  higher  temperature  (70°  F.)  than 
before,  when  it  is  gotten  as  "refined  wax."  To  convert  it  into  block 
paraffine,  it  must  be  washed  with  benzine,  pressed,  melted,  and  filtered 
through  bone-black  or  other  filtering  medium,  when  it  is  gotten  perfectly 
colorless  and  solidifying  to  a  hard,  translucent  block.  The  characters  of 
paraffine  will  be  referred  to  farther  on. 

The  distillation  of  residuum  is  continued  until  the  bottom  of  the  still 
becomes  red-hot,  when  yellow  vapors  issue  from  the  tail-pipe,  and  a  dense 
resinous  product,  of  a  light-yellow  color,  and  nearly  solid  consistency,  dis- 
tils over.  This  "  yellow  wax"  contains  anthracene,  chrysene,  picene,  and 
other  higher  pyrogenic  hydrocarbons.  Its  only  use  at  present  is  to  add  it 
to  paraffine  oils  to  increase  density  and  lower  cold  test.  Its  chemical  char- 
acter will  be  referred  to  again. 

The  coke  remaining  in  the  tar-still  at  the  end  of  the  process  amounts 
to  about  twelve  per  cent.,  and  is  largely  used  in  the  manufacture  of  electric- 
light  carbons.  Reduced  oils  gotten  by  careful  driving  off  of  the  light 
fractions  of  the  crude  petroleum,  without  cracking,  as  stated  before,  are  of 
great  value  as  lubricants.  They  are  generally  made  by  vacuum  distillation 
and  the  use  of  superheated  steam  instead  of  direct  firing.  They  are  either 
brought  into  the  market  at  once,  without  further  treatment,  or  after  a  bone- 
black  or  clay  filtration.  This  production  of  filtered  oils  is  usually  com- 
bined with  the  manufacture  of  vaseline,  or  petrolatum,  as  it  is  now  known 
in  the  "  United  States  Pharmacopoeia."  Taking  a  vacuum  residuum  as 
the  raw  material,  this  is  melted  and  run  on  to  filters  of  fine  granular  well- 
dried  bone-black.  The  filters  are  either  steam-jacketed  or  are  placed  in 
rooms  heated  by  steam-coils  to  120°  F.  or  higher.  The  first  runnings 
are  colorless,  and  all  up  to  a  certain  grade  of  color  go  to  the  manufacture 

*  With  the  lubricating  oils  from  certain  crude  petroleums,  it  is  found  advantageous  not 
to  wash  after  the  acid  treatment,  but  to  treat  immediately  with  a  strong  caustic  lye  (of 
33°  B.),  and  then  to  wash  as  a  final  step.  This  is  said  to  prevent  the  emulsifying  of  the  oil 
and  water  which  sometimes  takes  place  and  greatly  retards  the  separating  out  of  the  oil. 


26  PETKOLEUM  AND  MINERAL   OIL  INDUSTRY. 

of  vaseline.     Beyond  that  the  filtrate  is  known  as  "  filtered  cylinder  oil/' 
and  is  used  as  a  lubricant  exclusively. 

3.  OF  OZOKERITE  AND  NATURAL  PARAFFINE. — The  Galician  ozoker- 
ite is  in  the  main  a  natural  paraffine,  but  contains  some  oil  in  mechanical 
admixture.    Until  within  ten  to  twelve  years  ago  it  was  worked  exclusively 
for  the  production  of  paramne,  but  now  not  more  than  one-third  of  the 
annual  production  is  so  worked.     The  most  of  it  is  distilled,  yielding  five 
per  cent,  of  benzine,  fifteen  to  twenty  per  cent,  of  illuminating  oil,  fifteen 
per  cent,  of  "  blue  oil,"  and  about  fifty  per  cent,  of  paramne.     The  "  blue 
oil"  is  a  buttery-like  mixture  of  heavy  oils  with  paramne  crystals,  and  cor- 
responds to  a  paramne  oil  as  distilled  from  petroleum.    It  is  run  into  filter- 
presses  and  pressed,  first  cold,  and  then  the  press-cake  broken  up  and 
pressed  warm  to  remove  the  adhering  oils.    If  the  paramne  scale  so  obtained 
is  to  be  worked  up  into  block  paramne,  it  is  repeatedly  treated  with  benzine 
of  not  over  .785  specific  gravity,  and  pressed,  then  melted  and  filtered 
through  bone-black,  as  before  described  under  petroleum  paramne. 

If  the  ozokerite  is  to  be  worked  up  as  a  whole  into  the  wax-like  product 
known  as  Ceresine,  the  operation  may  be  conducted  in  one  of  two  ways. 
The  older  method  was,  after  a  preliminary  melting  of  the  ozokerite,  to 
free  it  from  earthy  impurities,  and  continuing  the  heating  until  all  water 
was  driven  out  of  the  melted  mass  to  treat  it  with  ten  per  cent,  of  sulphuric 
acid  as  long  as  sulphurous  oxide  was  evolved.  This  was  followed  by  treat- 
ment with  water  and  soda  solution.  To  more  thoroughly  separate  out  the 
black  carbonaceous  matter  produced  by  the  action  of  the  sulphuric  acid, 
one-half  to  one  per  cent,  of  stearic  acid  is  added,  and  this  then  saponified 
with  caustic  soda.  The  soap  so  formed  carries  down  all  carbonaceous 
matter  with  it,  and  allows  the  ceresine  to  be  filtered  clear  by  using  filter- 
paper.  The  product  is  the  Yellow  Ceresine,  much  resembling  beeswax.  The 
White  Ceresine,  resembling  bleached  beeswax,  is  gotten  by  melting  the  yellow 
ceresine  by  the  aid  of  steam,  digesting  it  with  bone-black,  with  frequent 
stirring,  and  filtering  through  paper.  The  newer  method,  more  frequently 
followed  now,  is  to  extract  the  ozokerite  with  benzine  and  ligroine.  The 
forms  of  apparatus  devised  for  this  purpose  allow  of  a  complete  exhaustion 
of  the  ozokerite  mass  and  a  subsequent  recovery  of  the  solvent  used  in  the 
extraction. 

The  natural  paraffine  that  separates  spontaneously  from  crude  petroleum, 
and  accumulates  at  times,  as  before  mentioned,  in  pipe-lines,  etc.,  is  chiefly 
used  as  a  basis  for  the  manufacture  of  vaseline  and  similar  products,  being 
melted  and  filtered  through  bone-black,  as  already  described. 

4.  OF  NATURAL  BITUMENS  AND  ASPHALTS  AND  OF  BITUMINOUS 
SHALES. — The  asphalt  or  solid  bitumen  from  the  Island  of  Trinidad  is 
exported  largely  to  the  United  States,  where  it  is  used  in  the  manufacture 
of  roofing  materials  and  of  asphalt  pavements.     It  yields  from  one  and 
three-fourths  to  two  and  a  half  per  cent,  of  paraffine  on  distillation,  and 
contains  sulphur  as  an  invariable  constituent.     Efforts  made  to  manufacture 
illuminating  and  other  oils  from  the  asphalt  have  failed  of  practical  results. 

Within  recent  years  artificial  asphalts  have  been  made  by  a  variety  of 
methods.  As  already  mentioned,  the  California  petroleums  all  seem  to 
have  an  asphaltic  instead  of  a  paraffine  base.  Hence  the  residuum  from 
the  refining  of  California  crude  oils  is  manufactured  into  artificial  asphalts. 
As  much  as  eleven  per  cent,  of  artificial  asphalt  has  been  obtained  in  prac- 
tice from  Ventura  County  petroleum. 


PROCESSES   OF   TREATMENT.  27 

Again,  artificial  asphalts  have  been  made  by  treating  Lima,  Ohio, 
petroleum  with  a  current  of  heated  air  until  all  volatile  products  are  driven 
out.  The  product  byerlite  is  thus  obtained. , 

Still  another  process  consists  of  melting  oil  residuums  with  sulphur  and 
heating  until  a  product  is  obtained  which  becomes  solid  on  cooling,  while 
hydrogen  sulphide  is  set  free.  By  far  the  most  interesting  production  of 
artificial  asphalt  is  that  of  Dr.  W.  C.  Day,  who  distilled  a  mixture  of  fish 
and  pine  wood  and  then  submitted  the  oil  obtained  to  a  secoud_destructive 
distillation.  The  residuum  left  when  the  distillation  was  carried  to  about 
425°  C.  solidified  to  a  black,  shining  mass,  which  in  physical  properties 
and  chemical  composition  strikingly  resembles  Utah  gilsonite. 

Very  much  more  important  are  the  industries  based  upon  the  distillation 
of  bituminous  shales.  As  these  shales  do  not  contain  either  liquid  or  solid 
hydrocarbons  as  such,  but  much  more  complex  compounds  called  bitumens, 
the  distillation  is  exclusively  a  destructive  one,  and  the  character  of  the 
distillation  products  becomes  dependent  upon  the  conditions  of  the  opera- 
tion, temperature  being  the  most  important  consideration.  The  theory  of 
destructive  distillation  will  be  entered  upon  at  length  later  (see  p.  347),  and 
we  will  here  only  say  that  for  paraffine  and  illuminating  oil  production  the 
distillation  is  essentially  a  low-temperature  one. 

The  material  originally  used  in  Scotland  was  Boghead  coal,  or  the 
Torbane  Hill  mineral  from  Bathgate,  near  Glasgow,  which  was  exhausted  in 
1872.  This  yielded  thirty -three  per  cent,  of  tar  or  oily  distillate  and  one 
to  one  and  one-half  per  cent,  of  crude  paraffine.  At  present  shales  are 
used,  which  furnish  about  thirteen  per  cent,  of  tar.  The  material  for  the 
German  paraffine  production  is  an  earthy  brown  coal,  which,  when  dry,  is 
of  a  light-brownish  or  yellowish  color  and  crumbling  character  ;  it  yields  on 
an  average  8.1  per  cent,  of  tar  and  .6  per  cent,  of  paraffine.  The  shales  are 
usually  distilled  with  some  steam,  which  increases  the  amount  of  the  tar,  as 
well  as  the  ammonia  from  the  shale.  The  distillation  may  be  intermit- 
tent, but  in  Scotland  is  now  carried  on  in  a  continuous  process  by  the  two 
methods  devised  by  Henderson  and  by  Young  &  Beilby  respectively,  the  ex- 
hausted shale  being  dropped  from  the  bottom  of  the  upright  retort  into  a 
combustion-chamber  beneath.  As  the  spent  shale  sometimes  contains  as 
much  as  from  twelve  to  fourteen  per  cent,  of  carbon,  this,  with  the  uucon- 
densed  gas  of  the  distillation,  suffices  for  fuel.  The  several  products  of  the 
distillation  are  (1)  gas,  which  is  freed  from  gasolene  vapors  by  passing  through 
a  coke  tower,  down  which  heavy  oil  is  trickling ;  (2)  watery  or  ammoniacal 
liquor,  which  is  obtained  to  the  amount  of  from  sixty-five  to  eighty  gallons 
per  ton  of  shale,  and  yields  from  fourteen  to  eighteen  pounds  of  sulphate  of 
ammonia  per  ton  worked ;  (3)  oily  liquor,  or  tar  proper,  of  dark  greenish 
color,  and  ranging  from  .865  to  .880  in  specific  gravity,  varying  in  amount 
from  thirty  to  thirty-three  gallons  per  ton  of  shale  used.  This  is  distilled 
in  cast-iron  stills  holding  from  two  hundred  to  two  thousand  gallons,  for 
the  purpose  of  purifying  it,  until  only  coke  amounting  to  from  five  to  ten 
per  cent,  of  the  tar  is  left.  The  mixed  distillates  (the  paraffine  magma  being 
added  to  the  others),  according  to  the  usage  of  the  German  paraffine-works, 
are  stirred  with  two  per  cent,  by  volume  of  caustic  soda  solution  in  order 
to  take  up  phenols  and  "  creosote/7  together  with  other  acid  products ;  the 
soda  washings  drawn  off  below,  and  the  supernatant  liquid,  after  washing 
with  water,  is  agitated  with  five  per  cent,  of  sulphuric  acid.  The  refined 
oil  is  now  fractionally  distilled.  The  first  fraction  (specific  gravity  .60  to 


28  PETROLEUM  AND  MINERAL   OIL  INDUSTRY. 

.68;  is  a  gasolene  used  for  carburetting  illuminating  gas  ;  the  second  (speci- 
fic gravity  .68  to  .76)  is  naphtha,  used  as  a  solvent;  the  third  (specific 
gravity  .81  to  .82)  is  illuminating  oil  ;  the  fourth  lubricating  oil  (specific 
gravity  .865  to  .900).  The  next  distillate  solidifies  on  cooling,  yielding 
brown  crystals  of  hard  paraffine,  whose  mother-liquor,  removed  by  a  filter- 
press,  is  "  blue  oil,"  whence  more  but  soft  crystals  can  be  obtained  by  arti- 
ficial refrigeration.  The  mother-liquid  of  these  is  again  treated  with 
vitriol  and  soda  and  distilled  ;  the  earlier  fractions  constitute  heavy  illumi- 
nating oil,  the  later  lubricating  oil.  The  percentage  of  solid  paraffine 
gotten  from  the  crude  shale  oil  is  from  eleven  to  twelve  and  a  half  per 
cent.  The  shale  oil  does  not  yield  any  product  corresponding  to  vaseline. 
B.  Hiibner,  a  German  paraffine  manufacturer,  believing  that  the  distilla- 
tions of  the  process  just  described  act  injuriously  upon  the  quantity  and 
hardness  of  the  paraffine  obtained,  has  modified  the  process  as  follows.  He 
treats  the  crude  shale  oil  with  sulphuric  acid,  and,  after  the  separation  of 
this,  distils  the  oil  over  several  per  cent,  of  slaked  lime.  After  the  crys- 
tallization of  the  paraffine  from  the  distillate,  it  is  purified  by  washing  with 
shale  oils  and  pressing.  He  thus  avoids  one  distillation  and  obtains  a  larger 
yield  of  paraffine,  distinctly  harder  in  character  than  the  usual  product. 

In  the  Scotch  shale-works  the  distilled  oil  is  treated  first  with  sulphuric 
acid  and  then  with  caustic  soda,  as  in  the  purifying  of  petroleum  oils,  and 
then  fractionally  distilled.  These  fractions  are  again  treated  with  acid  and 
alkali  before  being  considered  pure  enough  for  the  market.  In  some  works 
(as  those  at  Broxburn)  continuous  distillation  is  practised,  so  that  a  set  of 
three  boiler  stills  and  two  residue-  or  coking-stills,  used  together,  can  put 
through  thirty-five  thousand  gallons  of  crude  oil  per  day.  The  solid 
paraffine,  by  careful  processes  of  extraction,  can  be  brought  up  to  twelve 
and  a  half  per  cent. 

HE.  Products. 

1.  FROM  NATURAL  GAS.—  (a)  Fuel  Gas.—  The  great  value  of  natural 
gas  as  fuel  for  manufacturing  and  industrial  purposes  has  only  been  real- 
ized in  recent  years,  and  it  was  rapidly  introduced  as  a  substitute  for  coal 
and  coke.  In  Western  Pennsylvania'  and  Ohio,  particularly  in  Pittsburg 
and  its  vicinity,  for  manufacturing  purposes,  it  had  for  a  time  almost  en- 
tirely displaced  coal  and  coke,  but  its  production  has  reached  a  maximum, 
and  is  now  rapidly  falling  off  despite  the  opening  of  new  wells.  That 
natural  gas,  largely  made  up  of  methane  and  similar  hydrocarbons,  is  one 
of  the  best  of  gaseous  fuels  is  seen  from  the  accompanying  table,  prepared 
by  a  committee  of  the  American  Society  of  Mechanical  Engineers  : 

Table  showing  Comparative  Effects  of  Different  Gas  Fuels. 

Number  of  cubic  feet  needed 


Hydrogen  .............  183.1  293 

Water  gas  (from  coke)   .......  153.1  351 

Blast-  furnace  gas  ..........    51.8  1036 

Carbonic  oxide     ..........  178.3  313 

Marsh  gas  .............  571.0  93.8 

The  comparison  of  its  work  with  that  accomplished  with  solid  fuel,  as 
carried  out  at  the  works  of  Carnegie,  Bros.  &  Co.,  in  Pittsburg,  is  also 
given  by  the  same  committee.  Using  the  best-selected  coal,  and  charging 
the  furnace  in  such  manner  as  to  obtain  the  best  results,  the  maximum 


PRODUCTS.  29 

with  coal  was  nine  pounds  of  water  evaporated  to  the  pound  of  coal  con- 
sumed. "  In  making  the  calculations,  the  standard  seventy-six-pound 
bushel  of  the  Pittsburg  district  was  used  ;  six  hundred  and  eighty-four 
pounds  of  water  were  evaporated  per  bushel,  which  was  60.90  per  cent,  of 
the  theoretical  value  of  the  coal.  When  gas  was  burned  under  the  same 
boiler,  but  with  a  different  furnace,  and  taking  a  pound  of  gas  to  be  equal 
to  23.5  cubic  feet,  the  amount  of  water  evaporated  was  found  to  be  20.31 
pounds,  or  83.40  per  cent,  of  the  theoretical  heat-units  were  utilized." 

(6)  Illuminating  Gas. — The  processes  for  converting  natural  gas  into 
illuminating  gas  have  already  been  referred  to,  and  the  McKay  &  Critchlow 
process  described  in  detail.  The  production  by  this  process  of  a  permanent 
gas,  showing  no  condensation  of  vapors  at  the  drips,  and  of  eighteen  to 
twenty  candle-power,  is  said  to  have  been  demonstrated  at  Beaver  Falls, 
Pa.,  and  elsewhere. 

(c)  Lamp-black. — The  burning  of  natural  gas  so  as  to  cause  separation 
of  carbon,  which  is  then  collected  as  lamp-black,  has  been  referred  to. 
The  lamp-black  so  manufactured  has  been  shown  to  be  of  great  purity.  It 
is  miscible  with  water,  does  not  color  ether,  and  is  free  from  oily  matter.  A 
sample  of  it  analyzed  by  Professor  J.  W.  Mallet,  of  the  University  of  Vir- 
ginia, gave  the  following  results  :  Specific  gravity  at  17°  C.,  after  complete 
exhaustion  of  air,  1.729.  The  percentage  of  composition  was  as  follows : 

Carbon 95.057 

Hydrogen 0.665 

Nitrogen 0.776 

Carbon  monoxide 1.378 

Carbon  dioxide • 1.386 

Water 0.622 

Ash  (Fe2O3  and  CuO) 0.056 


99.940 


(d)  Electric-light  Carbons.  —  Still  another  use  for  carbon  from  natural 
gas  is  the  manufacture  of  carbons  for  electric  arc-lights,  the  purity  of  the 
material  making  a  very  pure  and  uniform  carbon  pencil  possible. 

2.  FROM  PETROLEUM.  —  The  names  of  commercial  products  obtained  from 
petroleum  have,  of  course,  been  almost  infinitely  varied,  as  each  manufacturer 
has  his  trade  names  for  his  special  products.  We  shall  only  designate  the 
generally-accepted  classes  of  products.  Beginning  with  the  lightest,  we  have  : 

Oymogene,  gaseous  at  ordinary  temperatures,  but  liquefiable  by  cold  or 
pressure.  Boiling-point,  0°  C.  (32°  F.).  Specific  gravity,  110°  B.  Used 
in  the  manufacture  of  artificial  ice. 

Rhigolene,  condensable  by  the  use  of  ice  and  salt.  Boiling-point, 
18.3°  C.  (65°  F.).  Specific  gravity,  0.60  or  100°  B.  Used  as  an  anes- 
thetic for  medical  purposes. 

Petroleum  Ether  (Sherwood  oil).  —  Boiling-point,  40°  to  70°  C.  Specific 
gravity,  .650  to  .660,  or  85°  to  80°  B.  Used  as  a  solvent  for  caoutchouc 
and  fatty  oils,  and  for  carburetting  air  in  gas-machines. 

Gasolene  (canadol).  —  Boiling-point,  70°  to  90°  C.  Specific  gravity,  .660 
to  .690,  or  80°  to  75°  B.  Used  in  the  extraction  of  oil  from  oil-seeds  and 
in  carburetting  coal-gas. 

Naphtha  (Danforth's  oil).  —  Boiling-point,  80°  to  110°  C.  Specific 
gravity,  .690  to  .700,  or  76°  to  70°  B.  Used  for  burning  in  vapor-stoves 
and  street-lamps,  as  a  solvent  for  resins  in  making  varnishes  and  in  the 
manufacture  of  oil-cloths. 


30  PETROLEUM  AND  MINERAL  OIL  INDUSTRY. 

Ligroine.— Boiling-point,  80°  to  120°  C.  Specific  gravity,  .710  to  .730, 
or  67°  to  62°  B.  For  solvent  purposes  in  pharmacy  and  for  burning  in 
sponge-lamps. 

Benzine  (deodorized). — Boiling-point,  120°  to  150°  C.  Specific  gravity, 
.730  to  .750,  or  62°  to  57°  B.  Used  as  a  substitute  for  turpentine,  for 
cleaning  printers'  type,  and  for  dyers',  scourers',  and  painters'  use. 

Burning  Oil,  or  Kerosene. — The  different  burning  oils  are  known  often 
by  special  names,  of  which  the  number  is  legion,  but  they  are  graded  by 
the  American  petroleum  exporters  chiefly  according  to  the  t\vo  standards  of 
color  and  fire-test.  The  colors  range  from  pale-yellow  (standard  white)  to 


straw  (prime-white)  and  colorless  (water- white).  The  fire-tests  (see  p.  33),  to 
which  the  commercial  oils  are  mostly  brought,  are  110°  F.,  120°  F.,  and 
150°  F. ;  that  of  110°  going  mainly  to  the  continent  of  Europe  and  to 
China  and  Japan,  and  that  of  120°  to  England.  An  oil  of  150°  F.,  fire- 
test,  and  water-white  in  color,  is  known  in  the  trade  as  "  headlight  oil." 
An  oil  of  300°  F.,  fire-test,  and  specific  gravity  .829,  is  known  as  "  mineral 
sperm,"  or  "  mineral  colza  oil."  "  Pyronaphtha"  is  a  product  from  Rus- 
sian petroleum,  somewhat  similar  to  mineral  sperm  oil.  It  has  a  specific 
gravity  of  .865,  and  fire-test  of  265°  F. 

Lubricating  oils  from  petroleum  have  assumed  an  importance  which 
is  increasing  every  year.  Some  crude  petroleums,  like  those  of  Franklin 
and  Smith's  Ferry,  Pa. ;  Mecca,  Ohio ;  Volcano,  W.  Va.,  and  other  local- 
ities, are  natural  lubricating  oils,  requiring  little  or  no  treatment  to  fit  them 
for  use.  The  other  petroleum  lubricating  oils  are  gotten  in  one  of  two 
ways.  Either  by  driving  off  the  light  hydrocarbons  from  the  crude  oil, 
yielding  what  is  called  a  "reduced  oil"  (see  p.  25),  or  they  are  the  oils 
gotten  by  distilling  the  petroleum  residuums  in  tar-stills. 

The  lightest  of  the  lubricating  oils,  varying  in  gravity  from  32°  B.  to 
38°  B.,  are  frequently  called  "  neutral  oils."  They  are  largely  used  for  the 
purpose  of  mixing  with  animal  or  vegetable  oils,  and  it  is  therefore  neces- 
sary that  they  should  be  thoroughly  deodorized,  decolorized,  and  deprived 
of  the  blue  fluorescence  or  "  bloom"  characteristic  of  petroleum  distillates 
that  contain  parafnne.  The  first  two  results  are  accomplished  by  bone- 
black  or  clay  filtration,  the  last  in  various  ways,  such  as  treatment  with 
nitric  acid,  addition  of  small  quantities  of  nitro-naphthalenes,  etc. 

Heavier  lubricating  oils  are  called  "  spindle"  and  "  cylinder"  oils.  The 
most  important  characters  to  be  possessed  by  these  oils  is  high  fire-test,  low 
cold-test,  and  a  high  viscosity.  (See  analytical  tests,  p.  34.) 

In  the  matter  of  lubricating  oils  the  Russian  products  are,  it  is  now 
admitted,  distinctly  superior  in  most  respects  to  the  American.  This  is  be- 
cause of  the  entire  difference  in  the  chemical  composition  of  the  two,  the 
hydrocarbons  characteristic  of  the  Russian  oil  being  heavier  and  showing 
less  tendency  to  solidify  at  low  temperatures  than  those  of  the  American 
oils.  The  following  statement  from  Boverton  Redwood  will  illustrate  this : 

Viscosity  Viscosity        Loss  in  viscosity, 

at  70°  F.  at  120°  F.  per  cent. 

Russian  oil  (sp.  gr.  .913) 1400  166  88 

American  oil  (sp.  gr.  .914) 231  66  71 

Russian  oil  (sp.  gr.  .907) 649  135  79 

American  oil  (sp.  gr.  .907) 171  58  66 

Russian  oil  (sp.  gr.  .898) 173  56  67 

American  oil  (sp.  gr.  .891) 81  40  50 

Refined  rape  oil  (for  comparison) 321  112  65 


PRODUCTS.  31 

It  is  true  that  the  disproportion  is  chiefly  at  lower  temperatures,  the  Rus- 
sian oil  losing  its  body  relatively  faster  than  the  less  viscous  American  oil. 

Paraffine  differs  somewhat  in  its  hardness  and  melting  point  according 
to  the  source  from  which  it  is  derived.  The  petroleum  paraffine  is  manu- 
factured generally  in  three  qualities,  fusing  at  125°  F.  (51.6°  C.),  128°  F. 
(53.3°  C.),  and  135°  F.  (57.3°  C.),  respectively,  paraffine  from  shales  melts 
at  56°  C.,  while  that  from  Rangoon  tar  melts  at  61°  C.  and  that  from 
ozokerite  at  62°  C.  The  harder  varieties  are  bluish-white,,  translucent, 
and  glassy  on  the  surface,  while  the  softer  varieties  are  alabaster-wlirte,  dull 
in  lustre  and  only  translucent  when  heated.  The  harder  varieties  are 
resonant.  Paraffine  is  readily  soluble  in  ether,  benzene,  and  all  light  hydro- 
carbons, ethereal  and  fatty  oils  and  carbon  disulphide,  not  entirely  in  abso- 
lute alcohol ;  while  ordinary  alcohol  only  takes  up  3.5  per  cent,  of  it. 
It  mixes  with  stearine,  spermaceti,  and  wax  in  all  proportions.  Exposed 
for  some  time  under  a  slight  pressure  to  a  temperature  below  its  melting 
point,  paraffine  wax  undergoes  a  molecular  change  and  becomes  trans- 
parent ;  but  upon  a  change  of  temperature,  or  upon  being  struck,  the  original 
translucent  appearance  returns. 

The  harder  variety  of  paraffine  is  used  chiefly  in  candle-making,  for 
which  purpose,  however,  a  small  proportion  (five  per  cent.)  of  stearic  acid 
must  be  added  to  it  to  prevent  the  softening  and  bending  of  the  candle.  It 
is  also  used  for  finishing  calicoes  and  woven  goods,  to  the  surface  of  which 
it  imparts  lustre.  The  softer  varieties  are  used  for  mixing  with  wax  and 
stearic  acid  in  candle-making,  for  the  preparation  of  translucent  and  water- 
proof paper  of  all  grades,  for  impregnating  Swedish  matches,  for  the  adul- 
teration of  "  chewing-gums/7  and,  in  recent  years,  for  "  enfleurage"  or  extract- 
ing delicate  perfumes  from  flowers. 

3.  FROM  OZOKERITE  AND  NATURAL  PARAFFINE. — The  character  of 
several  of  the  products  now  obtained  from  Galician  ozokerite,  viz.,  illuminat- 
ing and  lubricating  oils  and  paraffine,  has  been  sufficiently  described  under 
other  heads.     The  peculiar  product  known  as  Ceresine,  gotten  from  ozokerite 
without  distillation,  remains  to  be  described.     It  resembles  beeswax  very 
greatly  in  appearance,  but  is  of  lower  specific  gravity,  ranging  from  .915  to 
.925,  while  wax  is  from  .963  to  .969.     The  fusing  point  of  ceresine  varies 
from  68°  C.  to  80°  C.    Ceresine,  with  a  fusing  point  of  over  75°  C.,  shows  a 
fracture  and  structure  like  that  of  wax.     Its  behavior  to  water,  alcohol,  ether, 
chloroform,  fatty  and  ethereal  oils  is  exactly  like  that  of  paraffine.     Ceresine 
is  extensively  used  as  a  substitute  for  wax  as  well  as  for  most  of  the  uses 
before  given  for  paraffine.     It  is  commended  especially  for  the  formation  of 
matrices  for  galvano-plastic  work,  proving  in  this  respect  superior  to  gutta- 
percha.     It  is  also  being  used  instead  of  gutta-percha  for  hydrofluoric  acid 
bottles. 

4.  FROM  BITUMENS,  ASPHALTS,   AND  BITUMINOUS  SHALES. — It  is 
only  from  the  latter  of  these  that  products  of  commercial  importance  are 
derived.     From  the  crude  shale  oil,  already  described,  the  following  products 
are  obtained : 

Shale  Oil  Benzine. — Specific  gravity  .665  to  .720,  boiling-point  80°  to 
90°  C.,  is  colorless,  of  ethereal  odor,  and  slightly  peppermint-like  taste. 
It  is  used  somewhat  as  a  cleansing  benzine,  but  mainly  in  the  purifying  of 
the  shale  paraffine. 

Photogene  (shale  naphtha). — Specific  gravity  .720  to  .810,  boiling-point 
145°  to  150°  C.,  has  a  slight  ethereal  odor  and  peppery  taste.  It  dissolves 


32  PETROLEUM  AND  MINERAL   OIL  INDUSTRY. 

sulphur,  phosphorus,  iodine,  fats,  resins,  caoutchouc,  etc.  It  is  used  some- 
what for  illuminating  purposes  and  for  dissolving  the  fat  from  bones  and 
bleaching  them  in  the  preparation  of  artificial  ivory. 

Solar  oil  comes  into  the  market,  according  to  Grotowski,  in  two  grades, 
known  as  prima  and  secunda  oils,  one  with  specific  gravity  .825  to  .830 
and  a  boiling-point  175°  to  180°  C.,  and  the  other  with  specific  gravity 
.830  to  .835  and  a  boiling-point  195°  to  200°  C.  The  oils  are  of  slight, 
yellowish  color,  and  on  exposure  to  air  and  light  lose  their  free  burning 
qualities,  somewhat  through  the  reunifying  of  the  trace  of  creosote  which 
may  remain  in  them.  The  fire-test  of  the  solar  oil  is  generally  above  100°  C., 
and  they  are  in  general  both  cheap  and  excellent  burning  oils. 

Paraffine  OU. — The  paraffine  itself  has  been  described  under  a  previous 
heading.  The  expressed  paraffine  oil  is  used  considerably  as  a  lubricating 
oil,  but  is  of  greatest  importance  for  gas-making.  The  gas  from  this 
paraffine  oil  is  especially  rich  in  illuminating  hydrocarbons  and  is  free 
from  the  ordinary  impurities  of  coal-gas.  It  is  extensively  manufactured  in 
Germany,  in  the  Hirzel  and  Pintsch  forms  of  apparatus,  and  in  England  by 
the  Pintsch,  Keith,  and  Alexander  &  Patterson  processes,  and  compressed 
for  use  in  railway  carriages,  etc.  Its  characters  will  be  referred  to  more 
especially  under  the  heading  of  illuminating  gases. 

5.  VASELINE. — This  product  (petrolatum  of  the  United  States  Phar- 
macopoeia and  unguentum  paraffini  of  the  German  Pharmacopoeia)  may  be 
obtained  from  several  of  the  raw  materials  already  mentioned.  In  the 
United  States,  as  the  name  petrolatum  indicates,  it  is  a  petroleum  product 
and  may  be  called  "  natural  vaseline,"  as  it  is  merely  a  purified  preparation 
of  naturally  existing  petroleum  constituents  ;  in  Germany,  and  elsewhere  in 
Europe,  it  is  either  extracted  from  other  sources  (pomade  ozokerine),  or,  as 
the  name  unguentum  paraffini  indicates,  it  is  an  "  artificial  vaseline"  made 
by  the  solution  of  paraffine  in  paraffine  oil.  American  vaseline,  as  made 
by  the  Chesebrough  Company  and  others,  is  gotten  by  taking  a  vacuum 
residuum  (see  p.  25)  and,  without  any  treatment  with  sulphuric  acid  or 
other  chemicals,  simply  filtering  it  through  heated  bone-black.  In  this  way 
the  amorphous  character  of  the  hydrocarbons  is  not  changed  and  no  crys- 
talline paraffine  is  produced,  as  would  be  the  case  if  it  were  a  distillation 
product,  and,  moreover,  no  traces  of  sulphonic  acids  can  remain  from  the  acid 
treatment  to  interfere  with  its  use  as  a  basis  of  medicinal  ointments.  The 
petrolatum  of  the  United  States  Pharmacopoeia  may  be  either  a  soft  variety, 
melting  at  40°  C.  (104°  F.),  or  a  firmer  variety,  melting  at  51°  C.  (125°  F.). 

The  German  vaseline,  or  unguentum  paraffini,  is  made  by  taking  one  part 
of  ceresine  (paraffinum  solidum)  and  dissolving  it  in  three  parts  of  a  paraffine 
shale  oil,  known  as  "vaseline  oil"  (parqffinum  liquidum).  This  artificial 
vaseline,  as  Engler  and  Bohm  have  shown,*  easily  becomes  granular  on 
chilling,  and  shows  its  composite  nature  moreover  by  readily  separating  on 
distillation  into  ceresine  and  oil.  The  natural  vaseline  has  greater  homo- 
geneity and  is  more  viscous,  although  at  high  temperatures  it  seems  to  absorb 
more  oxygen  then  the  artificial  preparation.  At  temperatures  not  exceeding 
30°  C.  the  oxygen  absorption  seems  to  be  practically  nothing  in  either  case. 

Vaseline  is  largely  used  in  pharmacy  and  medical  practice  as  a  basis  of 
ointments  and  pomades. 

*  Dingier,  Polytech.  Journal,  262,  p.  468. 


ANALYTICAL  TESTS  AND  METHODS. 


33 


IV.  Analytical  Tests  and  Methods. 

1.  FOR   NATURAL   GAS. — These  are  the  methods  employed  for  the 
analysis  of  all  varieties  of  illuminating  gas,  and  will  be  referred  to  under 
that  heading.     (See  p.  387.) 

2.  FOR  CRUDE  PETROLEUM. — According  to  the  rule  of  the  New  York 
Produce  Exchange,  u  crude  petroleum  shall  be  understood  to  be  pure  natural 
oil,  neither  steamed  nor  treated,  free  from  water,  sediment,  or  any  adultera- 
tion, of  the  gravity  of  43°  to  48°  B."  (0.809  to  0.786  sp.  gr.),  ~In  order  to 
determine   whether    the    petro- 
leum is  a  "  pure  natural  oil"  a 

sample  is  subjected  to  fractional 
distillation,  each  fraction  being 
one-tenth  of  the  crude  oil  by 
volume,  and  the  density  of  the 
several  distillates  is  determined. 
The  regular  gradation  of  the 
densities  of  the  fractions  so  ob- 
tained is  taken  as  a  satisfactory 
indication  that  the  oil  is  a  nat- 
ural product. 

To  judge  of  the  commercial 
value  of  a  crude  petroleum  a 
fractional  distillation  is  also  de- 
sirable. For  this  purpose  Eng- 
ler's  system  of  distillation  is  to 
be  recommended.  He  uses  a 
distillation  flask,  the  shape  and 
dimensions  of  which  in  cubic 
centimetres  are  to  be  seen  in 
Fig.  6.  One  hundred  cubic 
centimetres  of  the  oil  is  intro- 
duced into  the  flask  by  the  aid 
of  a  pipette,  and  heat  is  ap- 
plied. At  first  wire  gauze  is 
interposed  between  the  burner 
and  the  flask,  but  afterwards 
the  naked  flame  is  employed, 
the  heat  being  so  regulated  that 
from  two  to  two  and  a  half 
cubic  centimetres  of  distillate  pass  over  per  minute. 


In  this  way  frac- 


tions differing  from  each  other  in  boiling-point  by  50°,  25°,  or  20°  C. 
can  be  obtained.  As  soon  as  the  requisite  temperature  (150°  C.  for  the 
first  fraction)  is  attained,  the  lamp  is  withdrawn  until  the  temperature  has 
fallen  at  least  20°  C.,  when  the  oil  is  reheated  to  the  boiling-point  and 
again  cooled,  this  process  being  repeated  until  no  more  distillate  is  obtained. 
The  oil  is  then  heated  to  the  next  boiling-point,  and  the  cooling  and 
reheating  process  repeated,  and  so  on.  In  this  way  results  can  be  obtained 
with  not  more  than  a  variation  of  one  per  cent,  even  in  the  hands  of  dif- 
ferent observers.  In  practice  the  fractions  up  to  150°  C.  are  added  together 
for  the  light  naphtha  or  benzine,  those  between  150°  C.  and  300°  C.  for  the 
burning  oil,  and  those  above  300°  C.  for  lubricating  oils  and  residuum. 

3 


34  PETROLEUM  AND  MINERAL  OIL  INDUSTRY. 

3.  FOR  PETROLEUM  PRODUCTS. — For  commercial  petroleum  products, 
which  are,  of  course,  mixtures  of  hydrocarbons,  the  boiling-point  becomes 
of  only  secondary  importance,  while,  with  reference  to  their  uses  as  illumi- 
nants,  the  element  of  safety  comes  into  consideration,  so  that  what  is  called 
"  flash  point"  and  "  burning  point,"  together  included  in  what  is  known  as 
"fire-test,"  becomes  important.  For  lubricating  oils,  the  consistency  or 
body  determined  in  the  viscosity-test  and  the  "  cold-test,"  or  point  to  which 
they  can  be  chilled  without  separating  paraffine,  are  important.  For 
paraffine  and  solid  products  the  melting-point  and  amount  of  oil  enclosed 
are  important.  And  for  all  classes  the  color  is  a  not  unimportant  gauge 
of  purity.  So  that  the  analytical  tests  for  petroleum  products  may  be 
summed  up  under  the  following  heads : 

Specific  gravity. 

Fire-test,  including  flash-point  and  burning  point. 

Cold-test. 

Viscosity. 

Melting  point. 

Compression-test. 

Colorimetric  tests. 

(a)  Specific  Gravity  Determinations. — While,  of  course,  the  methods  of 
the  specific  gravity  bottle  and  the  specific  gravity  balance  are  available,  the 
determinations  are,  in  the  case  of  the  liquid  petroleum  products,  almost  uni- 
versally made  with  hydf ometers,  and  these  may  be  of  two  kinds,  either 
graduated  so  that  specific  gravities  are  read  off  direct  in  decimal  fractions 
less  than  one,  or  graduated  in  the  arbitrary  scales  of  Beaume",  Brix,  Gay- 
Lussac,  or  Twaddle,  the  relations  of  which  to  simple  fractional  specific 
gravity  numbers  is  known.  In  America  and  Russia  the  Beaume"  scale  is 
universally  adopted ;  in  Germany,  the  Brix  spindle  is  used  officially  by 
customs  officers  •  in  France,  the  Gay-Lussac  ;  and  in  England,  the  Beaume" 
scale  for  liquids  lighter  than  water,  and  the  Twaddle  for  liquids  heavier 
than  water.  For  the  formulas  for  conversion  of  readings  of  these  scales 
into  specific  gravity  figures  and  for  a  complete  table  of  Beaume"  degrees  in 
comparison  with  the  corresponding  specific  gravity  figures,  see  Appendix. 
The  use  of  direct  specific  gravity  hydrometers  is  gradually  extending, 
especially  in  Germany,  as  they  do  away  with  the  necessity  of  all  reduction 
tables.  The  specific  gravity  tables  for  liquids  lighter  than  water  are  calcu- 
lated for  a  temperature  of  60°  Fv  and  in  practice  it  is  customary  to  add  to 
or  subtract  from  the  observed  specific  gravities  .004  for  every  10°  F. 
above  or  below  60°  F.,  and  this  is  found  to  afford  a  sufficiently  close 
approximation  to  the  truth  for  all  commercial  purposes  in  the  case  of  all 
the  ordinary  petroleum  products. 

(6)  Fire-test. — Just  as  crude  petroleum  is  dangerous  because  of  the  dis- 
solved gases,  although  its  specific  gravity  may  be  relatively  high,  so 
illuminating  oils  may  give  off,  at  temperatures  far  below  their  boiling- 
point,  small  amounts  of  inflammable  vapors,  which  might  make  these  oils 
dangerous  for  use  in  lamps  where  the  oil  reservoir  gradually  becomes  warm. 
A  distillate  may  have  vapors  of  higher  and  lower  boiling-point  carried 
over  with  it.  Two  points  may  be  determined  with  a  petroleum  oil,  the 
flashing  point,  or  the  temperature  at  which  the  oil  gives  off  vapors  which, 
mixing  with  air,  cause  an  explosion  or  flash  of  flame,  dying  out,  however, 
at  once,  and  the  burning  point,  or  the  temperature  at  which  a  spark  or 
lighted  jet  will  ignite  the  liquid  itself,  which  then  continues  to  burn.  The 


ANALYTICAL  TESTS  AND  METHODS. 


35 


later  point  is  usually  6°  to  20°  C.  higher  than  the  former,  but  there 
is  no  fixed  relation  between  them.  The  danger,  of  course,  begins  when 
an  oil  will  flash,  so  the  flash-point  is  generally  taken  as  the  basis  of  legal 
prescription ;  Austria  and  the  New  York  Produce  Exchange  alone  recog- 
nize formally  the  burning-test  instead  of  the  flash-test.  Most  European 
countries  and  most  of  the  States  in  the  United  States  prescribe  a  flash-test. 
The  United  States  have  no  national  regulation  on  the  subject. 

The  different  forms  of  apparatus  in  use  to  determine  the  safety  of  oils 
are  based  upon  either  one  of  two  principles, — the  direct  determination  of 
flash  or  burning  point,  or  the  determination  of  the  increased  tension  of 
vapor  which  the  oil  shows  as  the  temperature  rises.  The  second  class  is 

represented  by  a  single  form 
of  apparatus,  that  of  Salleron- 
Urbain,  used  to  some  extent  in 
France ;  the  first  class  is  rep- 
resented by  a  dozen  or  more  dif- 
ferent forms,  chiefly  of  Ameri- 
can, English,  and  German 
invention.  The  earliest  form, 
that  of  the  Tagliabue  open- 
cup  tester,  is  shown  in  Fig.  7, 
in  which  the  glass  cup  Z>, 
holding  the  oil  to  be  tested, 
is  heated  by  the  water-bath 
A.  When  the  thermometer, 
the  mercury  of  which  is  just 
immersed,  indicates  90°  F. 
(32°  C.),  the  spirit  lamp  is 
withdrawn  and  the  tempera- 
ture allowed  to  rise  more 
slowly  to  95°  F.  (35°  C.), 
when  a  lighted  splinter  of 
wood  is  passed  to  and  fro 
over  the  surface  of  the  oil. 
If  the  gas  rising  from  the  oil 
does  not  ignite,  the  water-bath 
is  heated  again  and  tests  are 
made  when  the  thermometer 
indicates  100°  F.  (38°  C.), 
104°  F.  (40°  C.),  and  108°  F. 
(42°  C.).  A  flash  at  108°  F. 
is  considered  as  marking  the 
oil  at  110°  F.  flash-test.  This 
form  was  the  first  one  offi- 
cially adopted  in  the  United 
States,  and  is  still  used  some- 
what in  Germany  and  Aus- 
tria. The  New  York  Produce 
Exchange  and  the  American 

petroleum  inspectors  have  now  adopted  an  open-cup  tester,  known  as  the 
Say  bolt  tester,  in  which  the  electric  induction-spark  is  made  to  pass  over 
the  top  of  the  open  oil-cup.  It  is  shown  in  Fig.  8.  F  is  a  water-bath,  the 


36 


PETROLEUM  AND  MINERAL  OIL  INDUSTRY. 


temperature  of  which  is  noted  by  an  independent  thermometer.  Although 
this  was  a  decided  improvement  on  the  first  Tagliabue  apparatus,  it  was 
found  that,  like  the  other  open-cup  apparatus,  it  gave  readings  which 
were  variable  and  higher  than  if  the  top  of  the  cup  were  covered.  This 
led  to  the  study  of  the  whole  subject  by  Sir  Frederick  Abel,  at  the  request 
of  the  English  government,  and  the  adoption  by  the  English  government 
as  their  official  standard  of  the  Abel  tester.  This  has  since  been  adopted 
by  the  German  government  as  well,  and  is  considered  by  many  to  be  the 
most  exact  now  in  use.  It  is  shown  in  Fig.  9.  The  following  is  a  de- 
scription of  the  details  of  the  apparatus  :  "  The  oil-cup  consists  of  JL 


FIG.  8. 


cylindrical  vessel,  two  inches  in  diameter,  two  and  two-tenths  inches  high 
(internal),  with  outward  projecting  rim  five-tenths  inch  wide,  three-eighths 
inch  from  the  top,  and  one  and  seven-eighths  inches  from  the  bottom  of 
the  cup.  It  is  made  of  gun-metal  or  brass  (17  B.  W.  G.),  tinned  inside. 
A  bracket,  consisting  of  a  short,  stout  piece  of  wire,  bent  upward,  and 
terminating  in  a  point,  is  fixed  to  the  inside  of  the  cup  to  serve  as  a  gauge. 
The  distance  of  the  point  from  the  bottom  of  the  cup  is  one  and  a  half 
inches.  The  cup  is  provided  with  a  close-fitting,  overlapping  cover,  made 
of  brass  (22  B.  W.  G.),  which  carries  the  thermometer  and  test-lamp.  The 
latter  is  suspended  from  two  supports  from  the  side  by  means  of  trunnions, 


ANALYTICAL  TESTS  AND  METHODS. 


37 


FIG.  9. 


upon  which  it  may  be  made  to  oscillate  ;  it  is  provided  with  a  spout,  the 
mouth  of  which  is  one-sixteenth  of  an  inch  in  diameter.  The  socket  which 
is  to  hold  the  thermometer  is  fixed  at  such  angle,  and  its  length  is  so  ad- 
justed, that  the  bulb  of  the  thermometer,  when  inserted  to  full  depth, 
shall  be  one  and  a  half  inches  below  the  centre  of  the  lid.  The  cover  is 
provided  with  three  square  holes,  one  in  the  centre,  five-tenths  inch  by  four- 
tenths  inch,  and  two  smaller  ones,  three-tenths  inch  by  two-tenths  inch, 

close  to  the  sides  and  opposite 
each  other.  These  three  holes 
may  be  closed  and  uncovered  by 
means  of  a  slide  moving  in 
grooves  and  having  perforations 
corresponding  to  those  on  the  lid. 
In  moving  the  slide  so  as  to  un- 
cover the  holes,  the  oscillating 
lamp  is  caught  by  a  pin  fixed  in 
the  slide  and  tilted  in  such  a  way 
as  to  bring  the  end  of  the  spout 
just  below  the  surface  of  the  lid. 
Upon  the  slide  being  pushed  back 
so  as  to  cover  the  holes,  the  lamp 
returns  to  its  original  position." 
Not  only  are  all  the  dimensions 
of  parts  in  the  Abel  apparatus 
prescribed  most  minutely,  but 
the  method  of  carrying  out  the- 
test  must  be  followed  in  minute 
particulars  in  order  to  get  accu- 
rate results.  The  opening  and 
closing  of  the  slide  must  be  regu- 
lated either  by  a  seconds  pendu- 
lum or,  as  in  the  official  German 
apparatus,  by  exact  clock-work. 
It  gives  a  flash-test  which,  on 
the  average,  is  27°  F.  lower  than 
that  of  the  open-cup  apparatus, 
so  that  73°  F.  Abel  test  is  taken 
as  the  equivalent  of  100°  F.  open- 
cup  test. 

A  German  apparatus,  which 
seems  to  be  fully  as  exact,  and  simpler  in  its  construction  and  operation,  is 
Heumann's  tester,  shown  in  Fig.  10.  In  it  the  results  are  to  a  considerable 
degree  independent  of  the  dimensions  of  the  oil-cup,  size  of  flame,  temper- 
ature of  the  water,  etc.  This  apparatus  shows  to  what  temperature  a  speci- 
men of  petroleum  must  be  heated  through  and  through  in  order  that  the 
vapor  given  off  may  suffice  to  make  an  explosive  mixture  with  a  volume 
of  air  exactly  equal  to  the  volume  of  oil.  The  glass  oil-vessel,  g,  is  set 
direct  in  the  metallic  water-bath,  6,  and  is  exactly  half-filled  with  oil  with 
the  aid  of  a  measure  accompanying  the  instrument.  The  agitating  paddles, 
c,  agitate  the  oil  and  the  air-and-vapor  mixture  independently.  The  little 
flame  or  lamp  for  igniting  the  explosive  mixture  is  attached  to  a  button 
at  d,  and  here  is  a  small  hole  through  which  the  gas-and-air  mixture  escapes, 


38 


PETROLEUM  AND  MINERAL  OIL  INDUSTRY. 


and,  when  ignited,  yields  a  flame  about  five  millimetres  high.  In  making 
the  test,  after  agitation  of  the  mixture,  the  button,  k,  is  pressed  down  until 
the  little  flame  is  pushed  below  the  surface,  when,  if  the  temperature  of 
flashing  has  been  reached,  it  ignites  the  explosive  mixture  of  air  and  vapor, 
and  is  blown  out  in  turn  by  the  slight  puff  of  the  explosion.  The  appa- 
ratus is  said  to  give  results  agreeing  perfectly  with  those  gotten  with  the 
more  complicated  but  official  Abel  tester.  Other  forms  of  apparatus  are 
those  of  Engler  (a  closed  test  apparatus  with  the  Saybolt  electric  spark 
attachment),  of  Parrish,  used  in  Holland,  and  of  Bernstein. 

Victor  Meyer  first  adopted  the  principle  that  the  true  flash-point  of  a 
petroleum  is  that  temperature  at  which  air,  shaken  with  petroleum,  can  be 
ignited  by  a  small  flame,  and  proposed  the  thorough  agitation  of  the 

warmed  oil  to  be  tested  with  air  be- 
fore applying  the  flame.  The  simplest 
form  of  apparatus  in  which  this  prin- 
ciple is  applied  is  the  flash-tester  of 
Stoddard,  shown  in  Fig.  11.  The 
air-current  escapes  from  a  fine-drawn 
opening  in  the  glass  tube,  and  must 
raise  a  foam  several  millimetres  in 
height  on  the  surface  of  the  oil.  The 
cylinder  containing  the  oil  may  be  a 
small  Argand  lamp-chimney,  and  the 

FIG.  11. 


FIG.  10. 


whole  apparatus  is  lowered  into  a  water-bath.  The  little  jet  of  flame  is 
passed  to  and  fro  over  the  opening  at  the  top  of  the  chimney,  while  the  ther- 
mometer, immersed  in  the  oil,  is  read. 

(c)  Cold  Test. — This  is  applied  chiefly  to  lubricating  oils.  The  execution 
of  it  with  Tagliabue's  standard  oil-freezer  is  shown  in  Fig.  12.  The  glass 
oil-cup,  four  inches  in  depth  and  three  inches  in  diameter,  is  adjusted  to  a 
rocking  shaft,  seen  at  the  side  of  the  cup,  so  as  to  show  by  its  motion 
whether  the  oil  is  congealing  or  not.  Surrounding  the  oil-cooling  chamber 
is  the  ice-chamber,  and  outside  of  this  is  a  non-conducting  jacket  filled 
with  mineral  wool.  Three  thermometers,  are  used  :  one  in  the  oil-cup  and 
the  other  two  in  the  ice-chamber  to  either  side.  Two  stopcocks  below, 
communicating  with  the  cooling-chamber,  allow  of  the  forcing  in  of  warm 
atmospheric  air  to  raise  the  temperature  within  when  necessary.  A  glass 
door  in  the  side  opposite  the  oil-cup  allows  of  the  reading  of  the  ther- 


ANALYTICAL  TESTS  AND  METHODS. 


39 


mometer  without  opening  the  cooling-chamber.  The  cold-test  is  also  fre- 
quently applied  by  simply  taking  the  oil  in  a  sample  bottle,  the  diameter  of 
which  is  about  one  and  a  half  inches,  chilling  it  in  a  freezing  mixture,  and 
noting  the  temperature  at  which,  on  inclining  the  tube,  the  oil  no  longer 
flows,  or  that  at  which  the  separation  of  paramne  commences. 

(d)  Viscosity  Test. — As  before  stated,  the  "  viscosity"  or  body  of  a  lubri- 
cating oil  is  one  of  its  most  important  characters.  Its  determination  is, 
therefore,  to  be  made  with  great  care.  The  earlier  forms  of  apparatus 
consisted  simply  of  glass  tubes,  of  pipette  form,  which,  being  filled  with  oil 
to  a  certain  mark,  were  allowed  to  empty  while  the  time  was  accurately 
noted.  The  pipette  was  set  in  a  hot-water  funnel  or  similar  vessel,  and 

FIG.  12. 


the  water  in  this  outer  vessel  brought  to  60°  F.,  so  that  the  observation  on 
the  oil  might  be  at  a  standard  temperature. 

Other  forms  are  those  of  Coleman,  Mason,  and  Redwood,  in  England, 
and  F.  Fischer  and  C.  Engler,  in  Germany.  The  Redwood  viscosimeter, 
a  very  accurate  instrument,  will  be  found  described  and  illustrated  fully  in 
"  Allen's  Commercial  Organic  Analysis"  (2d  ed.,  vol.  ii.  p.  1 98).  The  Fischer 
viscosimeter  is  shown  in  Fig.  13.  The  outer  vessel,  By  having  been  filled 
with  warm  water,  the  oil- vessel,  A,  has  placed  in  it  about  sixty-five  cubic 
centimetres  of  the  oil  sample,  filling  it  to  a  mark  on  the  inside.  When  the 
thermometer,  immersed  in  the  oil,  shows  the  proper  temperature,  fifty  cubic 
centimetres  are  allowed  to  run  into  a  graduated  flask  placed  below  and  the 
time  required  for  its  flow  noted.  The  exit-tube,  a,  consists  of  a  platinum 
tube  1.2  millimetres  wide  and  5  millimetres  long,  which  is  surrounded  by 
a  wider  copper  tube.  This  exit-tube  is  enlarged  conically  at  either  end, 


40 


PETKOLEUM  AND  MINERAL  OIL  INDUSTRY. 


above  to  allow  of  the  closing  by  the  conical  plug,  6,  and  below  to  allow  of 
better  flow  of  the  escaping  oil.  In  the  Engler  instrument,  illustrated  in 
Fig.  14,  still  greater  care  is  taken  to  insure  accurate  measurement  of  the 
volume  of  oil  operated  upon,  and  that  it  shall  flow  under  exactly  similar 
conditions  in  comparative  tests.  Two  hundred  and  forty  cubic  centimetres 
of  water  fill  the  inner  vessel  just  to  the  mark  c,  and  when  the  temperature 
of  20°  C.  (68°  F.)  is  reached,  two  hundred  cubic  centimetres  are  run  out 
into  the  vessel  below.  The  oil  to  be  tested  is  similarly  filled  in  to  the  mark, 
and  when  the  temperature  20°  C.  is  reached,  after  keeping  the  oil  at  this  for 
some  three  minutes,  the  plug,  6,  is  withdrawn,  and  two  hundred  cubic  centi- 
metres are  run  into  the  vessel  below,  while  the  time  required  is  accurately 

FIG.  14. 


FIG.  13. 


noted.  This  time  in  seconds,  divided  by  the  time  in  seconds  required  for  the 
running  of  the  same  volume  of  water,  gives  the  specific  viscosity  or  viscosity- 
grade,  as  Engler  terms  it. 

The  lubricating  value  of  oils  can  be  determined  best  by  actual  use  upon 
the  surfaces  where  friction  is  felt,  and  instruments  to  determine  such  value 
are,  therefore,  based  upon  experimental  trials  of  the  diminution  of  friction  on 
moving  surfaces,  when  covered  by  the  oils  to  be  compared.  Such  an  instru- 
ment is  the  well-known  Thurston  lubricating  oil-tester,  shown  in  Fig.  1 5, 
in  which  both  the  resistance  in  the  speed  of  revolution  of  a  rotating  axis  due 
to  friction  and  the  heating  of  the  axis  and  the  bearing  in  which  it  rotates  are 
measured. 

(e)  Melting  Point. — The  "  melting  point"  of  paraffine  should  rather  be 
called  the  congealing  point,  as  what  is  taken  usually  is  the  temperature  at 
which  the  sample,  after  having  been  melted,  and  while  in  the  process  of  cool- 


ANALYTICAL  TESTS  AND  METHODS. 


41 


FIG.  15. 


ing,  begins  to  solidify.  The  American  test  is  conducted  by  melting  sufficient 
of  the  samples  to  three-fourths  fill  a  hemispherical  dish  three  and  three- 
fourths  inches  in  diameter.  A  thermometer  with  a  round  bulb  is  suspended 
in  the  fluid  so  that  the  bulb  is  only  three-fourths  immersed,  and  the  ma- 
terial being  allowed  to  cool  slowly,  the  temperature  is  noted  at  which  the 
first  indication  of  filming,  extending  from  the  sides  of  the  vessel  to  the 
thermometer  bulb,  occurs.  The  English  test  is  made  by  melting  the 

sample  in  a  test-tube  about  three^quarters  of 
an  inch  in  diameter,  and  stirring  it  with  a 
thermometer  as  it  cools,  until  a  temperature  is 
reached  at  which  the  crystallization  of  the 
material  produces  enough  heat  to  arrest  the 
cooling,  and  the  mercury  remains  stationary 
for  a  short  time.  The  results  afforded  by  this 
test  are  usually  from  2J°  to  3°  F.  lower  than 
those  furnished  by  the  American  test.  The 
melting  point  is  also  sometimes  determined  by 
observing  the  temperature  at  which  a  minute 
quantity  of  the  sample  previously  fused  into  a 
capillary  tube,  and  allowed  to  set,  becomes 
transparent  when  the  tube  is  slowy  warmed  in 
a  beaker  of  water. 

(/)  Compression  Test. — Paraffine  scale  usu- 
ally contains  oil  and  sometimes  water.  The 
percentage  of  oil  is  determined  by  subjecting  a 
weighed  quantity  of  the  material  to  a  given 
pressure  for  a  specified  time  and  noting  the 
loss  in  weight.  The  test  is  made  at  60°  F.,  the  quantity  of  material  employed 
five  hundred  grains,  the  pressure  is  nine  tons  over  the  whole  surface  of  the 


FIG.  16. 


FIG.  17. 


circular  press-cake,  five  and  five-eighths  inches  in  diameter,  and  this  pressure 
is  maintained  for  five  minutes,  the  oil  expressed  being  absorbed  by  blotting- 
paper. 


42  PETROLEUM  AND  MINERAL  OIL  INDUSTRY. 

(g)  Oolorimetric  Tests. — The  color  of  petroleum  oil  is  determined  in  the 
United  States  (as  regards  oil  for  export),  in  England,  and  in  Russia  (in  the 
case  of  oil  for  export)  mainly  by  the  use  of  the  Wilson  chromometer.  In 
Germany  they  use  both  a  modification  under  the  name  of  the  Wilson- 
Ludolph  chromometer  and  Stammer's  colorimeter.  The  Wilson  instrument, 
shown  in  Fig.  16  and  Fig.  17,  is  fitted  with  two  parallel  tubes,  furnished 
with  glass  caps,  and  at  the  lower  end  of  the  tubes  is  a  small  mirror  by 
means  of  which  light  can  be  reflected  upward  through  the  tubes  with  an 
eye-piece.  One  of  these  tubes  is  completely  filled  with  the  oil  to  be  tested, 
and  beneath  the  other  tube,  which  remains  empty,  is  placed  a  disk  of  stained 
glass  of  standard  color.  On  adjusting  the  mirror  and  looking  into  the  eye- 
piece the  circular  field  is  seen  to  be  divided  down  the  centre,  each  half 
being  colored  to  an  extent  corresponding  with  the  tint  of  the  oil  and  of  the 
glass  standard  respectively.  An  accurate  comparison  of  the  two  colors 
can  thus  be  made.  The  glass  disks,  which  for  the  English  trade  are  of  five 
shades  of  color,  termed  good  merchantable,  standard  white,  prime  white, 
superfine  white,  and  water  white,  are  issued  by  the  Petroleum  Association  of 
London.  In  Germany,  the  Bremen  Exchange  recognizes  seven  shades  of 
color, — straw,  light  straw,  prime  light  straw  to  standard  white,  prime  light 
straw  to  white,  standard  white,  prime  white,  and  water  white. 

In  addition  to  these  special  tests  there  may  be  mentioned  a  general 
method  recently  devised  by  A.  Riche  and  G.  Halphen  (Journ.  Pharm. 
Chem.j  1894,  xxx.  289)  for  determining  whether  a  petroleum  distillate  has 
been  obtained  from  American  or  Russian  crude  petroleum,  and  for  distin- 
guishing crude  petroleum  from  mixtures  of  petroleum  distillate  and 
residuum.  The  process  consists  in  the  gradual  addition  by  means  of  a 
burette  of  a  mixture  of  equal  volumes  of  anhydrous  chloroform  and  ninety- 
three  per  cent,  alcohol  to  four  grammes  of  the  sample  of  the  oil  until  solution 
is  effected  and  the  liquid  becomes  clear.  It  was  found  that  samples  of  crude 
petroleum  required  much  more  of  the  solvent  to  produce  a  clear  liquid  than 
fractions  of  the  same  density  obtained  by  distillation,  and  that  the  higher 
boiling  fractions  of  American  petroleum  required  a  larger  quantity  of  the 
solvent  than  sufficed  for  the  Russian  product  of  corresponding  specific 
gravity. 

3.  FOR   OZOKERITE. — The  physical  tests  are  the  same  as  those  for 
paraffine  scale. 

4.  FOR  ASPHALTS. — When  asphalts  and  bitumens  are  to  be  used  for 
varnish-making,  the  determination  of  the  total  bitumen  soluble  in  carbon 
disulphide  or  oil  of  turpentine  suffices.     When,  on  the  other  hand,  the 
asphalt  is  to  be  considered  with  reference  to  its  value  for  asphalt  paving 
purposes,  it  is  necessary  to  examine  into  the  quality  of  the  bitumen.     For 
this   purpose  the  total   bitumen  (amount   soluble  in  carbon   disulphide), 
organic  non-bitumen,  and  ash  are  first  determined.     Then  the  amount  of 
bitumen  soluble  in  petroleum-naphtha  (so  called  petrolene)  is  ascertained. 
The  difference  between  this  and  the  total  bitumen  is  called  asphaltene. 
The  former  of  these  portions  is  in  general  tough  and  elastic,  while  the 
latter  is  hard  and  brittle.    For  paving  purposes  the  asphalt  should  contain 
an  excess  of  petrolene  over  asphaltene.     Instead  of  petroleum-naphtha 
and  carbon  disulphide,  acetone  and  chloroform  may  be  used  with  advan- 
tage for  the  extractions. 

The  liquid  asphalts  or  malthas  sometimes  contain  so  much  material 
volatile  at  temperatures  below  300°  F.  that  the  simple  determination  of 


BIBLIOGRAPHY  AND  STATISTICS.  43 

bitumen  soluble  in  petroleum-naphtha  would  be  misleading  and  valueless 
unless  they  were  previously  heated  to  drive  off  these  light  oils,  as  these 
volatile  portions  are  not  comparable  in  value  with  the  petrolene  of  solid 
asphalts.  Therefore  a  test  is  commonly  made  of  the  percentage  of  loss 
in  such  asphalts  when  heated  to  300°  F.  or  400°  F.  for  ten  hours,  and  this 
is  then  taken  in  connection  with  the  extraction  tests. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

The  following  list  of  titles  is  not  meant  to  be  complete,  but  only  gives  the  more 
important  published  works  of  the  last  thirty  years.  It  does  not  cover  periodical  literature, 
which  is  very  voluminous  : 

1865.— The  Oil  Regions  of  Pennsylvania,  W.  Wright,  New  York. 

1868.— Die  Industrie  der  Mineral  Oele,  von  H.  Perutz,  Part  I.,  Vienna. 

1874.— Das  Paraffin  und  die  Mineral  Oele,  M.  Albrecht,  Stuttgart 

1876-86. — Keports  of  the  Second  Geological   Survey  of  Pennsylvania  on  Oil  Kegions, 

Harrisburg,  Pa. 
1877. — Petroleum  Industrie  Nord  Amerikas,  H.  Hofer,  Berlin. 

Geological  Survey  of  the  Oil  Lands  of  Japan,  B.  S.  Lyman,  Tokio. 
1879  — Untersuchungen  iiber  naturliche  Asphalte,  R.  Kavser,  Nuremberg. 
1880.— Die  Industrie  der  Mineral  Oele,  H.  Perutz,  Part  II.,  Vienna. 
1881. — Petroleum  und  Erdwachs,  Burgmann,  Vienna. 
1883.— Petroleum  Central-Europas,  J."L.  Piedboeuf,  Diisseldorf. 
1884.— Petroleum  Distillation,  A.  N.  Leet,  New  York. 

Naphtha  and  Naphtha  Industrie,  V.  Ragosine,  St.  Petersburg. 

The  Region  of  Eternal  Fire,  Chas.  Marvin,  London 

Photogen  und  Schmierol  aus  Baku'scher  Naphta,  F.  Rossmassler,  Halle. 
1885. — Lemons  sur  le  Petrole  et  ses  Derives,  Chas.  Augenot,  Antwerp. 

Census  Report  of  1880  on  Petroleum  and  its  Products,  S.  F.  Peckham,  Washington. 

Destructive  Distillation,  Ed   J.  Mills,  third  edition,  London. 
1886. — Verarbeitung  der  Naphta  oder  des  Erdols,  F.  Rossmassler,  Halle. 
1886-88.— Mineral  ^Resources  of  the  United  States   for  1886-88  (Petroleum,  by  J.  D. 

Weeks),  Washington. 
1887.— Das  Erdol  von  Baku,  C.  Engler,  Stuttgart. 

Cantor  Lectures  on  Petroleum  and  its  Products,  B.  Redwood,  London. 

Practical  Treatise  on  Petroleum,  B.  Crew,  Philadelphia. 

Ueber  das  Deutsche  Rohpetroleum,  Kramer  und  Bottcher,  Berlin. 

Das  Deutsche  Erdol,  C.  Engler,  Berlin. 

Preliminary  Report  on  Petroleum  and  Inflammable  Gas,  E.  Orton,  Columbus,  Ohio. 

England  as  a  Petroleum  Power,  Chas.  Marvin,  London. 

Fette  und  Oele  der  Fossilien  (Mineral  Oele),  C.  Schaedler,  Leipzig. 

Petroleum,  its  Production  and  Uses,  B.  Redwood ,  New  York. 
1888. — Das  Erdol  und  seine  Verwandten,  H.  Hofer,  Braunschweig. 

Die  Deutsche  Erddle,  C.  Engler,  Stuttgart. 

Schmierol  Untersuchungen,  A.  Martens,  Berlin. 

L' Asphalte,  son  origine,  sa  preparation,  etc.,  Leon  Malo,  Paris. 
1889. — L'Industrie  du  Petrole,  Ph.  Delahaye,  Paris. 
1890. — Aux  Pays  du  Petrole — Histoire,  Origines,  etc.,  F.  Hue,  Paris. 
1892. — Das  Erdol  und  seine  Verarbeitung,  A.  Veith,  Braunschweig. 

Production,  Industrie  et  Commerce  des  Huiles  Minerales  aux  Etats-Unis,  Riche, 

Paris. 
1893. — Die  Petroleum  und  Schmierolfabrikation,  F.  A.  Rossmassler,  Leipzig. 

Vegetabilische  und  Mineral-Maschinenole,  L.  Andes,  Wien. 

Twenty  Years'  Experience  of  Natural  Asphalt,  W.  H.  Delano,  London. 
1894. — Die  Schmiermittel,  J.  Grossman,  Wiesbaden. 

Technologie  der  Landwirthschaftlichen  Gewerbe  und  Abhandlung  iiber  Mineral 
Oele,  Dr.  B.  von  Posauner,  4te  Auf.,  Wien. 

Gas-  and  Petroleum-yielding  Formations  of  California,  W.  L.  Watts,  Sacramento, 

California. 
1895. — Petroleum  and  Natural  Gas,  Wm.  T.  Brannt,  Philadelphia. 

Groves  and  Thorp's  Chemical  Technology,  vol.  ii.,  The  Petroleum  Industry  and 
Lamps,  Boverton  Redwood,  Philadelphia. 

Die  Fabrikation  der  Mineral  Oele,  W.  Scheithauer,  Braunschweig. 


44 


PETROLEUM  AND  MINERAL   OIL   INDUSTRY. 


1896. — Petroleum  and  its  Products,  Boverton  Redwood,  two  vols. .  London  and  Philadelphia. 

Le  Petrole,  Riche  et  Halphen,  Paris. 

Lubricating  Oils,  Fats,  and  Greases,  Geo.  H.  Hurst,  London. 

1897. — Oil-  and  Gas-yielding  Formations  of  Los  Angeles,  Ventura,  and  Santa  Barbara 
Counties,  Sacramento,  California. 

Die  Untersuchung  der  Schmierniittel,  Dr.  D.  Holde,  Berlin. 

Mineral  Oils  and  their  By-products,  I.  I.  Redwood,  London. 
1898. — Ueber  Hannoverisch  Erdoelvorkomnisse,  Dr.  Otto  Lang,  Hannover. 

On  the  Nature  and  Origin  of  Asphalt,  Clifford  Richardson,  New  York. 

A  Short  Hand-Book  of  Oil  Analysis,  A.  H.  Gill,  Philadelphia. 
1899. — Der  Asphalt  und  seine  Anwendung,  W.  Jeep,  Leipzig. 
1900. — Allen's  Commercial  Organic  Analysis,  third  edition,  vol.  ii.,  Partii.,  Philadelphia. 


STATISTICS. 


1.  FOR  NATURAL  GAS. — As  already  stated,  the  production  of  natural 
gas  in  the  United  States  has  reached  a  maximum  and  is  now  steadily 
decreasing. 

Value  of  Natural  Gas  consumed  in  the  United  States.     1893-1898. 


LOCALITIES. 

1893. 

1894. 

1895. 

1896. 

1897. 

1898. 

Pennsylvania         .         .   . 

$6,488,000 

$6,279,000 

$5  852  000 

$5  528  610 

$6  242  543 

$6  806  742 

New  York 

210000 

249  000 

241  530 

256  000 

200  076 

229  078 

Ohio  .   . 
West  Virginia  
Indiana  

1,500,000 
123,000 
5,718,000 

1,276,100 
395,000 
5,437,000 

1,255,700 
100,000 
5,203,200 

1,172,400 
640,000 
5,043  635 

1,171,777 
912,528 
5  009  208 

1,488,308 
1,334,023 
5  060  969 

Other  States  

307,250 

318,300 

354,220 

361,867 

290,290 

377,693 

Total  

$14,346,250 

$13,954,400 

$13,006,650 

$13,002,512 

$13,826,422 

$15,296,813 

(Mineral  Kesources  of  the  United  States  for  1898.) 

2.  FOR  PETROLEUM. — The  production  of  petroleum  in  the  United 
States  during  the  past  five  years,  according  to  "  Mineral  Industry  of  the 
United  States  for  1899,"  is  as  follows : 


Barrels  (42  gal.).  Metric  tons. 

1895 55,033,495  7,677,364 

1896 55,254,795  7,708,236 

1897 57,124,783  7,992,046 

1898 51,774,465  7,243,509 

1899 54,048,100  7,566,734 


Value  at  place  of 
production. 

$74,776,761 
65,753,216 
44,914,360 
42,100,522 
62,911,637 


The  distribution  of  this  production  over  the  different  States  for  the 
years  1 894-99  is  thus  shown  on  the  same  authority  : 


STATE. 

1894. 

1895. 

1896. 

1897. 

1898. 

1899. 

Appalachian  field  .  .  . 

Barrels. 
30,622,336 

Barrels. 
30,406,693 

Barrels. 
33,455,571 

Barrels. 
34,724,700 

Barrels. 

31,100,360 

Barrels. 

33,158,664 

Ohio  (Lima  field)  
Indiana  (Lima  field)   .  .  . 
Colorado    

13,891,795 
3,688,666 
803,000 

18,415,631 
4,386,132 
530,000 

15,362,176 
4,659,290 
400,  000 

15,307,376 
4,353,138 
650,000 

13,377,590 
3,751,307 
650,000 

13,443,425 
3,772,011 
600,000 

California  .             ... 

600000 

1  245  339 

1257  780 

1,911  569 

2  249  088 

2  365  000 

Texas 

none 

none 

none 

65  000 

544  620 

600  000 

Other  States  

44  300 

49300 

119,478 

113,000 

101,500 

109,000 

Total 

49  650  097 

55  033  095 

55  254  295 

57  124  783 

51  774  465 

54  048  100 

BIBLIOGRAPHY  AND  STATISTICS. 


45 


The  exportation  of  crude  oil  and  the  various  products  therefrom  for 
the  years  1894-98  is  shown  in  the  annexed  table  from  the  authority  last 
quoted,  p.  537 : 


Year 
ending 
Dec.  31st. 

Mineral  crude  (all  gravi- 
ties). 

Naphthas,  benzine, 
gasolene,  etc. 

Illuminating  oils. 

Gallons. 

Dollars. 

Gallons. 

Dollars. 

Gallons. 

3)ollars. 

1894 
1895 
1896 
1897 
1898 

114,269,000 
116,108,000 
118,133,000 
121,864,000 
120,436,000 

4,617,000 
6,286,000 
6,032,000 
5,044,000 
5,019,000 

14,832,000 
12,922,000 
13,641,000 
13,704,000 
17,255,000 

904,000 
1,000,000 
1,123,000 
1,020,000 
1,071,000 

726,727,000 
686,006,000 
758,076,000 
804,446,000 
764,823,000 

29,799,000 
43,540,000 
49,704,000 
46,896,000 
38,895,000 

Year 
ending 
Dec.  31st. 

Lubricating  and  heavy 
paraffine  oils,  etc. 

Residuum  and  tar, 
pitch,  etc. 

Total. 

Gallons. 

Dollars. 

Gallons. 

Dollars. 

Gallons. 

Dollars. 

1894  .    . 
1895  .    . 
1896  .    . 
1897  .    . 
1898  .    . 

38,975,000 
47,876,000 
51,705,000 
52,679,000 
65,526,000 

5,137,090 
6,239,000 
6,770,000 
6,732,000 
7,626,000 

119,000 
170,000 
521,000 
12,247,000 
30,436,000 

10,000 
15,000 
28,000 
335,000 
815,000 

894,922,000 
863,082,000 
942,076,000 
1,004,941,000 
998,476,000 

44,463,000 
57,131,000 
63,657,000 
60,007,000 
53,423,000 

According  to  the  Petroleum  Review,  the  domestic  consumption  of  refined 
petroleum  in  1890  reached  11,000,000  barrels ;  in  1891, 12,000,000  barrels ; 
in  18'92,  13,000,000  barrels;  and  in  1893,  14,000,000  barrels. 

The  exportations  of  paraffine  and  paraffine  wax  for  the  years  1895-97 
have  been,  according  to  "  United  States  Bureau  of  Statistics,"  as  follows  : 


1895 95, 076, 165  pounds,  valued  at  $3, 569,614 

1896 105,882,575       "  "  4,406,841 

1897 126,365,128       "  "  4,957,096 


Closely  connected  with  the  oil-fields  of  the  United  States  are  those  of 
Canada.  The  production  and  value  of  Canadian  petroleum  for  the  years 
1894-99  are,  according  to  "The  Geological  Survey  of  the  Dominion  of 
Canada/'  as  follows : 


Production  in  barrels  of 
35  imperial  gallons. 

1894 829,104 

1895 726,138 

1896 726,822 

1897 709,857 

1898 758,391 

1899 808,570 


Value. 

$835,322 
,086,738 
,155,647 
,011,546 
,061,747 
,202,020 


Next  in  importance  to  the  oil-fields  of  the  United  States  and  rapidly 
increasing  in  their  production  are  those  of  Russia.  The  total  produc- 
tion of  crude  petroleum  on  the  Apsheron  peninsula  and  shipments  of 
petroleum  products  from  Baku  for  the  years  1894-98,  according  to 
"  Mineral  Resources  of  the  United  States  for  1898-99,"  p.  144,  were  as 
follows : 


46  PETROLEUM  AND  MINERAL   OIL  INDUSTRY. 

(1  barrel  =  1.38  metric  centners  =  8.42  poods  =  1.59  hectolitres.) 


Years. 


Production, 


Shipments  from  Baku. 


Illuminating 
oil. 


Lubricating 
oil. 


Residuum. 


Crude  oil. 


Total. 


1894 
1895 
1896 
1897 
1898 


Barrels. 
37,811,773 
47,713,983 
49,633,252 
54,744,303 
60,597,544 


Barrels. 

8,704,156 

9,898,288 

10,569,670 

11,042,054 

11,569,804 


Barrels. 

782,396 

825,489 

1,084,095 

1,114,180 

1,273,961 


Barrels. 
23,667,482 
22,050,232 
22,616,271 
27,106,357 
29,628,484 


Barrels. 
2,102,690 
1,849,780 
3,117,898 
2,896,333 
5,365,770 


Barrels. 
35,256,724 
34,754,254 
37,511,687 
42,303,912 
48,015,281 


Of  the  production  of  1893,  amounting  to  5,320,000  tons,  1,790,000 
tons  were  obtained  from  38  fountain- springs,  the  remainder  being  pumped 
from  wells.  Of  this  production  in  1893,  4,775,440  tons  were  worked  up 
with  the  production  of  1,402,728  tons  of  kerosene,  102,095  tons  of  lubri- 
cating oil,  4136  tons  of  benzine,  7758  tons  of  asphalt,  gasolene,  etc.,  and 
2,351,240  tons  of  residuals.  Thus,  3.41  tons  of  crude  petroleum  were  used 
for  the  production  of  one  ton  of  kerosene  or  burning  oil.  The  residuals 
are  now  very  largely  used  (especially  in  Russia)  for  fuel  on  railways, 
steamers,  and  in  factories  (Journ.  Soc.  Chem.  Ind.,  1894,  p.  1235). 

The  petroleum  production  of  Galicia,  the  third  most  productive  source, 
has  been,  according  to  Austrian  official  statistics  quoted  in  "  The  Mineral 
Industry  for  1898,"  as  follows : 

MO«™  f_na  Value  in  florins 

Metric  tons.  (=40.5  cents) . 

1893 96,331  3,008,819 

1894 111,930  3,252,554 

1895 188,634  4,464,353 

1896 262,356  5,188,855 

1897 275,204  5,876,692 

The  production  of  crude  petroleum  for  Roumania  in  recent  years  is  thus 
given  in  "Mineral  Resources  of  the  United  States  for  1898-99,"  p.  167  : 

Barrels  Barrels 

(42  U.  S.  gallons).  (42  U.  S.  gallons). 

1894 507,254   1897 570,886 

1895 575,200   1898 767,304 

1896 543,348 

The  production  in  British  India  (chiefly  Burmah)  for  the  years 
1894-97,  according  to  the  same  authority  (p.  162),  amounted  to : 

Barrels  Value 

Gallons.  (42  gallons) .  (rupees  =  $0.436). 

1894  11,139,597  318,274  1,100,709 

1895 13,013,990  371,828  1,542,591 

1896  .  15,057,094  430,203  1,793,355 

1897 19,128,828  546,538  2,263,772 

The  production  of  Germany,  the  only  other  country  yielding  any 
notable  quantity,  for  the  years  1894-98,  has  been,  according  to  the  same 
authority  (p.  170) : 

Metric  tons.  Value. 

1894          17,232  |233,387 

1895          17,051  230,989 

1896          20,395  285,243 

1897 23,314  335,147 

1898 25,789  378,770 


BIBLIOGRAPHY  AND  STATISTICS. 


47 


3.  FOB  OZOKERITE  AND  NATURAL  PARAFFINE. — The  production 
of  ozokerite  in  Galicia  in  recent  years  is  thus  given  in  "  Mineral  Resources 
of  the  United  States  for  1898-99,"  p.  267 : 


Metric  tons. 

1893 5624.8 

1894 6743.1 

1895 , 6644.5 

1896  .  .     7210.0 


Short  tons. 
6198.5 
7431.0 
7322.0 
7945.0 


The  production  of  Utah  ozokerite  (refined)  has  been  : 


1890 350,000  pounds 

1891 50,000       " 

1892 130,000       " 

1893 None  since. 


'158.9  metric  tons),  valued  at  $26,250 
'  23  "  "  ),  "  "  3,000 
*  59  "  "  ),  "  "  7,800 


4.  FOR  ASPHALT  AND  SHALE  OIL  INDUSTRY. — The  production  of 
asphalt  and  bituminous  rock  in  the  United  States  in  recent  years  has  been, 
according  to  "Mineral  Resources  of  the  United  States  for  1898-99"  : 

Short  tons.  Value. 

1894 60,570  $353,400 

1895 68,163  348,281 

1896 80,503  577,563 

1897 75,945  664,632 

1898 76,337  675,649 

Of  this  76,337  tons  about  2000  tons  is  bituminous  limestone,  some 
24,000  tons  of  various  grades  of  liquid  or  solid  asphaltum,  and  the  bal- 
ance is  bituminous  sandstone. 

The  importations  of  asphaltum  of  various  kinds,  according  to  "  Min- 
eral Resources  of  the  United  States  for  1898-99,"  have  been : 

Long  tons.  Value. 

1894 102,505  $313,680 

1895 79,557  210,556 

1896 96,192  304,596 

1897 115,528  392,770 

1898 69,857  203,385 

The  estimated  quantity  of  bituminous  shale  distilled  in  recent  years  in 
Scotland,  according  to  Boverton  Redwood  ("  Petroleum  and  its  Products," 
vol.  ii.  p.  406),  was : 


1890 2,180,483  tons. 

1891 2,337,932    " 

1892 2,077,076    " 


1893 1,947,842  tons. 

1894 1,982,409    " 


The  following  are  the  figures  for  the  German  mineral-oil  trade  for 
1892-93.  Forty-eight  shale-oil  works  were  operated  with  1297  ovens 
and  1067  workmen;  20,521,453  hectolitres  of  coal  were  distilled,  and 
1,195,892  centners  of  tar  and  5,651,566  centners  of  coke  were  obtained. 
The  tar  was  valued  at  4,345,422  marks  and  the  coke  at  1,643,748  marks. 
On  working  up  the  tar  there  were  obtained  159,250  centners  of  hard  and 
soft  paraffine,  102,306  centners  of  solar  oil,  and  623,691  centners  of  differ- 
ent paraffine  oils.  The  value  of  the  combined  products  was  11,098,496 
marks. 


48  INDUSTRY   OF  THE   FATS  AND   FATTY  OILS. 


.       CHAPTER   II. 

INDUSTRY   OF   THE    FATS   AND   FATTY   OILS. 

I.  Raw  Materials. 

1.  OCCURRENCE  OF  THE  MATERIALS. — The  fats  and  fatty  oils  are  of  both 
vegetable  and  animal  origin.  They  occur  not  only  widely  spread  through 
these  two  kingdoms  of  nature,  but  constitute  often  the  larger  proportion  by 
weight  of  the  material  in  which  they  are  found.  No  part  of  the  plant 
seems  to  be  entirely  wanting  in  fat,  although  that  found  in  the  leaves  is 
more  of  a  wax-like  character  than  the  oil  obtained  from  the  seeds  and 
fruit ;  in  the  animal,  fats  are  present  in  all  tissues  and  organs  and  in  all 
fluids  with  the  exception  of  the  normal  urine.  In  plants  the  percentage  of 
fat  seems  to  be  in  inverse  ratio  to  the  percentage  of  starch  and  sugar,  and 
ranges  from  sixty-seven  per  cent,  in  the  Brazil  nut  to  one  per  cent,  in  barley. 
While  the  oil-bearing  plants  are  far  too  numerous  to  allow  of  a  complete 
enumeration  here,  it  will  be  desirable  to  state  first  the  occurrence  of  those 
technically  most  important,  and  afterwards  to  examine  those  physical  and 
chemical  differences  which  lie  at  the  basis  of  their  different  uses.  Similarly 
the  most  important  animal  oils  and  fats  will  first  be  enumerated. 

(a)  VEGETABLE  OILS,  FATS,  AND  WAXES. — Castor  oil  (oleum  ricini, 
ricinus-oel)  is  extracted  by  pressure  or  heat  from  the  seeds  of  the  Rieinus 
communis,  originally  from  the  East.  It  is  a  thick  oil,  of  specific  gravity 
.9667  at  15°  C.,  colorless  or  yellowish,  transparent,  of  mild  taste,  but  be- 
coming rancid  on  long  exposure  to  air,  miscible  with  alcohol  and  ether,  and 
easily  saponifiable.  The  shelled  seeds  yield  from  fifty  to  sixty  per  cent,  of 
the  oil. 

Cotton-seed  oil  (oleum  gossypii  seminum,  baumwollen-samen-oel)  is 
obtained  by  pressure  from  the  hulled  seeds  of  the  several  species  of  Gossyp- 
ium,  or  cotton-plant.  The  raw  oil  is  brownish-yellow  in  color,  somewhat 
viscid,  of  specific  gravity  .922  to  .9306  at  15°  C.,  and  separates  some 
palmitin  at  from  6°  C.  to  12°  C.  The  refined  oil  has  a  straw-yellow  color, 
or  is  colorless,  of  pleasant  nutty  flavor;  specific  gravity,  .9264  at  15°  C. ; 
boils  at  about  600°  F.,  and  congeals  at  about  50°  F.  for  summer-  and 
32°  F.  for  winter-pressed.  Even  at  the  ordinary  temperature,  cotton-seed 
oil  deposits  "  stearine"  on  standing.  The  finer  brands  of  cotton-seed  oil 
intended  for  edible  and  culinary  purposes  are  freed  from  this  "  stearine"  by 
chilling  or  simply  by  allowing  the  oil  to  stand  for  some  time  in  large 
storage  tanks.  It  possesses  slight  drying  properties,  and  is  saponifiable, 
but  is  chiefly  used  in  adulterating  olive,  lard,  sperm,  and  other  oils.  The 
hulled  seeds  yield  from  eighteen  to  twenty  per  cent,  of  the  crude  oil. 

Hemp-seed  oil  (oleum  cannabis,  hanf-oel)  is  obtained  from  the  seeds  ofj 
the  Cannabis  sativa,  or  common  hemp.  It  has  a  mild  odor  but  mawkish 
taste,  and  greenish-yellow  color,  turning  brown  with  age.  Its  specific 
gravity  at  15°  C.  is  .9276.  It  is  freely  soluble  in  boiling  alcohol.  Has 


RAW   MATERIALS.  49 

weaker  drying  properties  than  linseed  oil,  but  is  used  in  paint  and  varnish 
manufacture  and  in  making  soft  soaps.  The  seeds  contain  some  thirty  per 
cent,  of  the  oil. 

Linseed  oil  (oleum  lini,  lein-oel)  is  pressed  from  the  seeds  of  the  Linum 
usitatissimum,  or  flax-plant.  The  oil  differs  in  quality  according  to  the 
method  of  its  production.  By  cold  pressure  is  obtained  twenty  to  twenty- 
one  per  cent,  of  a  pale,  tasteless  oil,  which  is  used  in  cooking  as  a  substi- 
tute for  lard  or  butter  in  Russia  and  Poland.  By  warm  pressure  is  obtained 
twenty-seven  to  twenty-eight  per  cent,  of  an  amber- colored  or  dark-yellow 
oil.  It  is,  when  fresh,  somewhat  viscid,  but  as  a  drying  oil  it  gradually 
absorbs  oxygen  and  becomes  thick  and  eventually  dry  and  hard.  The 
specific  gravity  of  the  fresh  oil  is  .935  at  15°  C.  It  is  used  almost  exclu- 
sively in  the  preparation  of  paints,  varnishes,  printer's  ink,  and  u  oil-cloth." 
(See  p.  101.) 

Poppy-seed  oil  (oleum  papaveris,  mohn-oel)  is  obtained  from  the  seeds 
of  the  opium  poppy  by  pressure,  is  of  pale-yellow  color,  and  slightly 
sweetish  taste.  Specific  gravity,  .925  at  15°  C.  The  cold-drawn  oil,  the 
oil  of  the  first  pressing,  is  almost  colorless,  or  very  pale  golden  yellow ; 
this  is  the  "  white  poppy-seed  oil"  of  commerce.  The  second  quality,  ex- 
pressed at  a  higher  temperature,  is  much  inferior,  and  constitutes  the  u  red 
poppy-seed  oil"  of  commerce.  It  is  used  for  salads,  paints,  soaps,  and  to 
adulterate  olive  and  almond  oils.  The  seeds  yield  from  forty-seven  to  fifty 
per  cent,  of  oil. 

Walnut  oil  (huile  de  noix,  wallnuss-oel)  is  obtained  from  the  seeds  of 
the  common  walnut-tree,  Juglans  regia.  The  fruit  to  be  pressed  should  be 
fully  ripe  and  kept  for  several  months  before  being  pressed,  as  the  fresh 
seeds  yield  a  turbid  oil.  The  cold-drawn  oil  is  very  fluid,  almost  colorless, 
or  of  a  pale  yellow-greenish  tint,  and  has  a  pleasant  smell  and  agreeable 
nutty  taste;  the  hot-pressed  oil,  on  the  other  hand,  has  a  greenish  tint  and 
an  acrid  taste  and  smell.  Walnut  oil  is  a  very  good  drying  oil,  and  at 
least  equal  if  not  superior  in  that  respect  to  linseed  oil.  It  is  chiefly  used 
by  artists  for  paints,  as  it  dries  to  a  varnish  film  less  liable  to  crack  than 
the  film  of  linseed-oil  varnish.  Moreover,  the  better  brands  of  walnut  oil 
being  almost  colorless,  it  is  preferred  to  any  other  oil  for  white  paints. 

Sunflower  oil  (huile  de  soleil,  sonnenblumen-oel)  is  obtained  from  the 
seeds  of  the  sunflower  (Hdianihus  annuus),  and  is  a  limpid  pale-yellow  oil 
of  mild  taste  and  pleasant  smell.  Specific  gravity,  .925  at  15°  C.  It 
belongs  to  the  class  of  drying  oils,  but  dries  more  slowly  than  linseed  oil. 
The  cold- drawn  oil  is  also  used  in  Russia  for  culinary  purposes,  while  that 
expressed  at  a  higher  temperature  is  employed  in  soap-making  and  for  the 
manufacture  of  varnishes. 

Almond  oil  (oleum  amygdalae,  mandel-oel)  is  the  fixed  oil  obtained  from 
both  the  sweet  and  the  bitter  almond  The  former  contains  the  more  oil, 
but  the  latter  is  cheaper,  and  the  residual  cake  can  be  utilized  for  the  prep- 
aration of  the  essential  oil  of  bitter  almonds.  The  oil  is  odorless,  agree- 
able to  the  taste,  and  of  yellow  color.  Specific  gravity,  .919  at  15°  C.  It 
is  used  in  pharmacy  and  medicine  and  in  soap-making. 

Corn  oil  (maize  oil,  mais-oel)  is  obtained  from  the  seeds  of  the  maize  or 
Indian  corn,  either  by  expressing  the  seed  before  it  is  employed  for  the 
manufacture  of  starch,  or,  where  the  corn  has  been  fermented  for  the  pro- 
duction of  alcohol,  by  recovering  it  from  the  residue  of  the  fermentation 
vats.  Prepared  by  the  former  process,  it  is  of  a  pale-yellow  or  golden- 

4 


50  INDUSTRY  OF  THE   FATS  AND   FATTY   OILS. 

yellow  color,  whereas  the  oil  obtained  by  the  latter  process  is  reddish  brown. 
Specific  gravity,  .921  to  .924  at  15°  C.  The  oil  has  slight  drying  proper- 
ties only.  It  is  used  as  a  burning  and  lubricating  oil  and  for  soap-making. 
It  is  also  employed  in  place  of  cotton-seed  oil  for  the  adulteration  of  lard. 

Sesame1  oil  (gingili  oil,  teel  oil,  sesam-oel)  is  obtained  from  the  seeds  of 
the  Sesamum  orientale  and  Sesamum  indicum.  The  oil  possesses  a  yellow 
color,  is  free  from  odor,  and  has  a  pleasant  taste.  The  cold-drawn  oil  is 
therefore  considered  equal  to  olive  oil  for  table  use.  It  has  very  slight  dry- 
ing properties.  Specific  gravity,  .923  at  15°  C.  In  addition  to  its  use  as  an 
edible  oil,  the  inferior  grades  are  used  in  soap-making  and  as  burning  oil. 

Ben  oil  (oleum  balatinum,  behen-oel)  is  obtained  by  expression  from  the 
seeds  of  the  several  species  of  Moringia.  Colorless,  odorless  oil,  not  readily 
turning  rancid.  It  is  used  by  perfumers  for  extracting  odors  and  for  lubri- 
cating clocks  and  light  machinery. 

Cacao  butter  (oleum  theobromatis)  is  obtained  from  seeds  or  nibs  of 
Theobroma  cacao.  Pure  white  fat,  with  pleasant  odor  and  taste.  Fuses  at 
86°  F.  (30°  C.).  Specific  gravity,  .945  to  .952.  It  is  used  for  cosmetics 
and  for  pharmaceutical  preparations. 

Cocoa-nut  oil  (oleum  cocois,  cocos-oel)  is  obtained  from  the  dried  pulp 
(copra)  of  the  cocoa-nut  by  expression.  An  oil  of  the  consistency  of  butter, 
fusing  at  73°  to  80°  F.  (22.7°  to  26.6°  C.).  When  fresh,  is  white  in  color 
and  of  sweet  taste  and  agreeable  odor,  but  easily  becomes  rancid.  It  is 
easily  saponified,  even  in  the  cold.  It  is  used  in  the  manufacture  of  candles 
and  padded  soaps.  (See  p.  64.) 

Colza  and  rape  oils  (oleum  brassicse,  oleum  rapse)  are  practically  identical. 
They  are  extracted  from  the  several  varieties  of  JBrassica  campestris.  The 
seeds  are  called  cole-seed  or  rape-seed.  The  term  "  colza  oiP'  is  generally 
applied  to  refined  rape  oil.  The  crude  oils  are  used  as  lubricating  oils,  and 
are  of  dark,  yellow-brown  color.  Refined  and  freed  from  albumen  and 
mucilage,  they  become  bright-yellow.  The  specific  gravity  of  the  refined 
oil  is  .9132  at  15°  C.  Rape  oil  is  used  for  lamps,  for  lubricating  machinery, 
and  for  adulterating  both  almond  and  olive  oils. 

Olive  oil  (oleum  olivarum,  oliven-oel)  is  expressed  from  the  fruit  of  Olea 
Europcea.  It  differs  greatly  in  quality  according  to  the  method  by  which  it  is 
obtained.  The  purest  is  nearly  inodorous,  pale-yellow,  with  pure  oily  taste. 
Specific  gravity,  .918  at  15°  C.  Does  not  decompose  or  become  rancid 
easily,  and  congeals  at  32°  F.  to  a  granular  solid  mass.  The  percentage 
of  oil  amounts  to  thirty-two  per  cent.,  of  which  twenty-one  per  cent,  is 
furnished  by  the  pericarp,  and  the  remainder,  which  is  inferior,  by  the  seed 
and  woody  matter  of  the  fruit.  It  is  used  extensively  as  an  article  of  food 
or  condiment,  in  pharmacy,  as  an  illuminant  and  lubricant,  and  in  soap- 
making.  The  lowest  grade,  u  tournant  oil,"  has  a  high  per  cent,  of  free 
fatty  acids  and  readily  emulsifies  with  sodium  carbonate  solution. 

Arachis  oil  (peanut  oil,  erdnuss-oel).  This  oil  is  obtained  from  earth- 
nuts,  the  seeds  of  Arachis  hypog&a.  The  cold-drawn  oil  of  the  first  ex- 
pression is  nearly  colorless,  and  has  a  pleasant  taste  resembling  the  flavor 
of  kidney  beans.  Specific  gravity,  .917  at  15°  C.  The  best  qualities  of 
the  oil  are  used  for  table  oil  and  the  inferior  grades  for  soap  making. 

Palm  oil  (oleum  palmse,  palm-oel)  is  obtained  from  the  fruit  of  several 
species  of  palm.  The  fresh  palm  oil  has  an  orange-yellow  tint,  a  sweetish 
taste,  and  an  odor  resembling  violets.  Its  specific  gravity  is  about  .968. 
Its  consistency  is  that  of  butter  or  lard.  It  ordinarily  becomes  rancid 


RAW  MATERIALS.  51 

rapidly,  and  hence  usually  contains  free  acid.    It  is  used  in  candle-  and  soap- 
making,  and  also  to  color  and  scent  ointments,  pomades,  soap,  powders,  etc. 

Carnauba  wax  is  obtained  from  the  leaves  of  the  carnauba  palm, 
Copernicia  cerifera  of  Brazil.  Its  specific  gravity  is  .999  and  its  melting 
point  185°  F.  (84°  C.).  It  is  brittle  and  of  yellowish  color.  It  is  exten- 
sively used  in  the  manufacture  of  candles. 

Japan  wax  is  obtained  by  boiling  the  berries  of  several  trees  of  the  genus 
Rhus,  from  incisions  in  the  stems  of  which  flows  the  famous  Japan  lacquer 
varnish.  It  is  properly  a  fat,  as  it  consists  almost  entirely  of  glyceryl  palm- 
itate.  Its  specific  gravity  is  .999  and  melting  point  120°  F.  (49°  C.). 
When  freshly  broken,  the  fractured  surface  is  almost  white  or  slightly 
yellowish-green  and  the  odor  tallow-like.  It  is  used  for  mixing  with 
beeswax  in  the  manufacture  of  candles  and  in  the  manufacture  of  wax- 
matches. 

Myrtle  wax,  a  solid  fat  obtained  by  pressure  from  the  berries  of  myriea 
cerifera.  Specific  gravity  1.005  at  15°  C. ;  fusing  point  45°  to  46°  C. 
It  is  used  as  a  substitute  for  beeswax  and  particularly  in  candle-making. 

(6)  ANIMAL  OILS,  FATS,  AND  WAXES. — Neat's-foot  oil.  Prepared  from 
the  feet  of  oxen  collected  from  the  slaughter-houses.  It  is  a  clear,  yellowish 
oil  of  specific  gravity  .916  at  15°  C.  It  does  not  congeal  until  below 
32°  F.,  and  is  not  liable  to  become  rancid.  Of  great  value  as  a  lubricant, 
and  used  for  softening  leather  and  grinding  of  metals. 

Butter  fat  is  the  oily  portion  of  the  milk  of  mammalia,  but  in  practice 
the  term  is  restricted  to  that  obtained  from  cows'  milk.  The  pure  fat  con- 
stitutes from  eighty-five  to  ninety-four  per  cent,  of  the  finished  butter.  The 
pure  fat  has  a  specific  gravity  of  .910  to  .914,  and  its  melting  point  varies 
from  85°  to  92°  F.  For  fuller  account  of  manufactured  butter,  see  under 
milk  (p.  254). 

Lard  and  lard  oil  (adeps,  schweine-schmalz)  is  the  fat  of  the  pig  melted 
by  gentle  heat  and  strained.  The  crude  lard  is  white,  granular,  and  of  the 
consistency  of  a  salve,  of  faint  odor  and  sweet,  fatty  taste.  Its  specific  gravity 
is  .938  to  .940  at  15°  C.  Exposed  to  the  air  it  becomes  yellowish  and 
rancid.  When  pressed  at  32°  F.,  it  yields  sixty-two  parts  of  colorless  lard 
oil  and  thirty-eight  parts  of  compact  lard.  The  lard  is  used  in  cooking,  the 
lard  oil  for  greasing  wool,  as  a  lubricant  and  an  illuminant. 

Tallow  and  tallow  oil  (sevum,  talg).  Tallow  is  the  name  given  to  the  fat 
extracted  from  "  suet,"  the  solid  fat  of  oxen,  sheep,  and  other  ruminants. 
The  quality  of  the  tallow  varies  according  to  the  food  of  the  cattle  and  other 
circumstances,  dry  fodder  inducing  the  formation  of  a  hard  tallow.  Its 
melting  point  varies  from  115°  to  121°  F.  The  best  qualities  are  whitish, 
but  it  has  in  general  a  yellowish  tint.  Beef  tallow  contains  about  sixty-six 
per  cent,  of  solid  fat  and  thirty-four  per  cent,  of  olein  or  tallow  oil ;  mutton 
tallow  contains  about  seventy  per  cent,  of  solid  fat  and  thirty  per  cent,  of 
tallow  oil.  The  oil  is  used  chiefly  in  the  manufacture  of  soaps  and  the 
harder  tallow  for  candle-making. 

Bone  fat  is  a  whitish-yellow  fat  obtained  by  boiling  bones,  and  is  used 
in  soap-making. 

Cod-liver  oil  (oleum  jecoris  ceselli,  leberthran)  is  an  oil  ranging  in  color 
according  to  the  method  of  its  preparation  from  pale-straw  to  dark-brown, 
and  of  specific  gravity  .923  to  .924  or  even  .930  at  15°  C.  The  finer 
qualities  are  used  for  medicinal  purposes,  the  darker  for  tanners7  and 


x^ 

/T^      OF  THE 

f  UNIVERSITY 

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V^  CAf 


52  INDUSTRY  OF  THE   FATS  AND   FATTY  OILS. 

Menhaden  oil  is  obtained  from  the  Alosa  menhaden,  a  kind  of  herring. 
Is  used  for  soap-making  and  tanning,  and,  when  pure,  as  a  substitute  for 
cod-liver  oil. 

Shark  oil  is  prepared  from  the  livers  of  various  species  of  shark.  It  is 
the  lightest  of  the  fixed  oils,  the  specific  gravity  ranging  from  .865  to 
.876.  It  is  used  in  the  adulteration  of  cod-liver  oil  and  for  tanning. 

Whale  oil  (train  oil)  is  extracted  from  the  blubber  of  the  common  or 
Greenland  whale.  Is  yellow  or  brownish  in  color  and  of  disagreeaole  odor. 
Specific  gravity  .920  to  .931.  It  is  used  for  illumination  and  for  soap- 
making. 

Sperm  oil  is  procured  from  the  deposits  in  the  head  of  the  sperm  whale. 
In  the  living  animal,  the  solid  spermaceti  is  held  in  solution  in  the  liquid 
sperm  oil ;  when  the  liquid  becomes  cold  the  spermaceti  separates  out.  The 
oil  is  very  limpid,  relatively  free  from  odor,  and  burns  well  in  lamps. 
Specific  gravity,  .875.  It  is  used  as  a  lubricant  on  account  of  its  low  cold 
test  and  its  viscosity,  and  as  an  illuminant. 

Spermaceti  (cetaceum,  walrath)  is  the  solid  wax  separated  out  from  the 
accompanying  oil.  It  is  yellowish  at  first,  but  when  purified  is  white, 
brittle,  and  scaly.  Its  specific  gravity  is  .943  at  15°  C. ;  melting  point, 
43°  to  49°  C.  It  is  only  slightly  soluble  in  alcohol,  benzene,  and  petroleum- 
ether,  but  easily  soluble  in  ether,  chloroform,  and  carbon  disulphide.  It  is 
used  in  the  manufacture  of  candles  and  in  pharmaceutical  preparations. 

Wool  grease  (woll-fett,  lanolin,  or  adeps  lanse).  Sheep's  wool  contains 
a  large  amount  of  fatty  matter  of  a  peculiar  character.  It  contains  free 
fatty  acids,  esters  of  cholesterol  and  isocholesterol,  and  the  free  alcohols 
just  named.  When  purified  from  fatty  acids  it  yields  lanolin,  which  has 
the  property  of  taking  up  large  quantities  of  water  in  an  emulsion,  and  is 
used  extensively  in  medicine.  The  esters  are  true  waxes  and  not  glycer- 
ides. 

Beeswax  (cera  flava,  bienenwachs)  is  the  substance  of  which  the  cells  of 
the  honey-bee  are  constructed.  The  crude  melted  wax  is  a  tough,  compact 
mass  of  yellow  or  brownish  color,  granular  structure,  faint  taste,  and  honey- 
like  odor.  When  bleached  it  becomes  white.  Specific  gravity  .959  to 
.969  ;  melting  point  62°  to  64°  C.  It  is  used  in  making  candles,  ointments, 
and  pomades. 

Chinese  wax  (insect  wax)  is  deposited  by  an  insect,  Coccus  cerifera,  upon 
the  Chinese  ash-tree.  It  is  a  white,  very  crystalline,  and  brittle  wax,  resem- 
bling spermaceti  in  appearance.  Specific  gravity  .973  at  15°  C. ;  fuses  at 
82°  to  83°  C.  It  is  slightly  soluble  in  alcohol  and  ether,  very  soluble  in 
benzene.  It  is  used  in  candle-making. 

2.  PHYSICAL  AND  CHEMICAL  CHARACTERS  OF  THE  DIFFERENT  OILS 
AND  FATS. — (a)  Physical  Properties. — Most  of  the  vegetable  fats  are  liquid 
at  ordinary  temperatures,  because  of  the  relatively  high  percentage  of  olein 
they  contain.  Cocoa-nut  oil,  palm  oil,  cacao  butter,  and  a  few  others  have 
a  buttery  consistence  on  account  of  the  palmitin  present.  The  fats  of 
animals  feeding  on  straw  and  hay  are  solid,  because  of  the  stearin  present ; 
the  fats  of  carnivorous  animals  are  all  softer ;  the  fat  of  fishes  is  liquid  at 
ordinary  temperatures,  and  somewhat  differently  constituted  chemically. 
The  solid  waxes,  both  vegetable  and  animal,  are  in  general  differently 
constituted  from  the  softer  fats. 

The  fats  and  oils  are  almost  insoluble  in  water  (if  the  water  contains 
albumen,  gum,  or  alkaline  carbonates  in  solution  they  readily  form  an 


RAW  MATERIALS.  53 

emulsion  with  it  on  shaking) ;  alcohol  only  dissolves  them  sparingly ;  ether, 
carbon  disulphide,  chloroform,  benzene,  turpentine  oil,  fusel  oil,  and  acetone 
dissolve  them  readily. 

On  exposure  to  the  air,  the  fats,  and  particularly  the  fatty  oils,  absorb 
oxygen.  The  heat  developed  by  this  oxidation  at  times  suffices  to  inflame 
wool  and  cotton  tissues  soaked  with  the  oil.  The  oils  which  absorb  oxygen  in 
this  way  become  thick,  and  finally  dry  to  translucent  resinous  masses.  Such 
oils  are  called  "  drying  oils,"  and  are  used  in  painting  and  varnish^making. 
(See  p.  101.)  The  specific  gravity  of  all  the  fats  and  oils  is  less  than  unity, 
although  the  vegetable  waxes  are  only  very  slightly  less. 

The  boiling-points  of  the  oils  and  fats  cannot  in  general  be  taken  as 
distinctive,  as  many  of  them  begin  to  decompose  when  distilled  under  ordi- 
nary pressure.  Their  fusing  and  congealing  points  are  more  important; 
particularly  in  the  case  of  oils  used  as  lubricants  does  the  latter  denote  the 
different  value  of  the  oil  for  use  at  low  temperatures. 

(b)  Chemical  Composition  of  the  Oils,  Fats,  and  Waxes. — The  fatty  oils, 
as  distinguished  from  the  mineral  oils  (see  p.  13)  and  the  volatile  oils  (see 
p.  94),  belong  to  the  class  of  compound  ethers.  They  are  salt-like  bodies, 
composed  of  characteristic  acids  (oleic,  palmitic,  and  stearic),  known  as  fatty 
acids,  in  combination  with  an  alcohol  or  base.  In  most  cases  the  base  is 
the  triatomic  alcohol  glycerine,  so  that  the  oils  are  said  to  be  glycerides  of 
the  several  fatty  acids.  Some  few,  known  as  waxes,  do  not  contain  glycerine, 
but  a  monatomic  alcohol  in  combination  with  the  fatty  acid.  Most  of  the 
animal  and  vegetable  fats  contain  the  three  proximate  constituents,  olein, 
palmitin,  and  stearin,  the  combinations  of  oleic,  palmitic,  and  stearic  acids 
respectively  with  glycerine.  In  the  more  liquid  oils  the  olein  predominates, 
in  the  more  solid  palmitin  or  stearin.  The  so-called  "  drying  oils"  contain 
a  different  acid — linoleic  acid — in  combination  with  glycerine.  The  fish 
oils  contain  a  variety  of  the  lower  fatty  acids  and  some  solid  unsaponifiable 
alcohols  like  cholesterin.  The  most  satisfactory  classification  of  the  oils 
and  fats  is  that  of  A.  H.  Allen,*  which  is  here  given  in  abstract. 

I.  Olive  Oil  Group. — Vegetable  oleins.  Vegetable  non-drying  oils.    Lighter  than  Groups 
II.,  III.,  and  IV.     Yield  solid  elaidins  with  nitrous  acid.     Includes  olive,  almond,  earth- 
nut,  ben,  rape-seed,  and  mustard  oils. 

II.  Cotton-seed  Oil  Group. — Intermediate  between  drying  and  non-drying  oils.     Un- 
dergo more  or  less  drying  on  exposure.     Yield  little  or  no  elaidin.     Includes  cotton-seed, 
sesame,  sunflower,  hazel-nut,  and  beech-nut  oil. 

III.  Linseed  Oil  Group. — Vegetable  drying  oils.     Yield  no  elaidin.     Of  less  viscosity 
than  the  non-drying  oils.     Includes  linseed,  hemp-seed,  poppy-seed,  niger-seed,  and  walnut 
oils. 

IV.  Castor  Oil  Group. — Medicinal  oils.    Very  viscous  and  of  high  density.     Includes 
castor  and  croton  oils. 

V.  Palm  Oil  Group. — Solid  vegetable  fats.     Do  not  contain  notable  quantities    of 
glycerides  of  lower  fatty  acids.     Includes  palm  oil,  cacao  butter,  nutmeg  butter,  and  shea 
butter. 

VI.  Cocoa-nut  Oil  Group. — Solid  vegetable  fats,  in  part  wax-like.     Several  contain 
notable  proportions  of  the  glycerides  of  lower  fatty  acids.    Includes  cocoa-nut  oil,  palm- 
nut  oil,  laurel  oil,  Japan  wax,  and  myrtle  wax. 

VII.  Lard  Oil  Group. — Animal  oleins.     Do  not  dry  notably  on  exposure,  and  give 
solid  elaidins  with  nitrous  acid.     Includes  neat's-foot  oil,  bone  oil,  lard  oil,  and  tallow 
oil. 

VIII.  Tallow  Group. — Solid  animal  fats.     Predominantly  glycerides  of  palmitic  and 
stearic  acid,  although  butter  contains  lower  glycerides.     Includes  tallow,  lard,  bone  fat, 
wool  fat,  butter  fat,  oleomargarine,  and  manufactured  stearin. 

*  Commercial  Organic  Analysis,  2d  ed.,  vol.  ii.  p.  63. 


54 


INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 


,  IX.  Whale  Oil  Group. — Marine  animal  oils.  Characterized  by  offensive  odor  and 
reddish-brown  color  when  treated  with  caustic  soda,  Includes  whale,  porpoise,  seal,  men- 
haden, cod-liver,  and  shark-liver  oils. 

X.  Sperm  Oil  Group. — Liquid  waxes.     Are  not  glycerides  but  ethers  of  monatomic 
alcohols.     Yields  solid  elaidins.     Includes  sperm  oil,  bottle-nose  oil,  and  dolphin  oil. 

XI.  Spermaceti  Group. — Waxes  proper.     Are  compound  ethers  of  higher  monatomic 
alcohols,  with  higher  fatty  acids  in  free  state.     Includes  spermaceti,  beeswax,  Chinese  wax, 
and  carnauba  wax. 

3.  EXTRACTION  OF  THE  RAW  MATERIALS  AND  PURIFICATION  OF  THE 
SAME. — The  method  of  extraction  of  the  oils  and  fats  is,  of  course,  deter- 
mined to  a  considerable  degree  by  their  physical  condition.  Solid  fats,  like 
tallow  and  lard,  are  obtained  free  from  the  enclosing  membranes  by  melting 
the  finely-chopped  material  and  drawing  off  the  fat  in  the  melted  state ; 

FIG.  18. 


animal  oils  are  extracted  mainly  by  boiling  out  with  water ;  oil  fruits  and 
seeds  are  ground  fine,  and  then  the  oil  obtained  by  submitting  the  meal  to 
pressure,  either  cold  or  with  the  aid  of  heat,  or  the  oil  is  extracted  by  solvents 
like  carbon  disulphide  and  petroleum  ether. 

In  the  extraction  of  fats  by  the  process  of  melting,  three  forms  of 
procedure  are  followed :  (1),  the  so-called  "  cracklings'7  process,  a  melting 
over  direct  fire,  known,  too,  as  the  "  dry  melting  ;"  (2),  the  melting  over  direct 
fire  with  the  addition  of  dilute  sulphuric  acid,  known  as  the  "  moist  melt- 
ing;" and  (3),  the  melting  by  the  aid  of  steam.  In  the  first  process,  a 


KAW  MATERIALS.  55 

little  water  is  added  and  the  tallow  or  other  chopped  fat  is  heated  in  open 
vessels.  The  mixture  of  fat  globules  and  water  at  first  gives  it  a  milky 
appearance,  but,  as  soon  as  the  water  is  driven  off,  the  cell  membranes 
shrivel  more  and  more  together,  forming  the  cracklings,  and  the  fat 
appears  as  a  clear,  fused  liquid.  A  constant  stirring  is  required  in  order 
to  prevent  the  fragments  of  membrane  from  sticking  to  the  sides  or 
bottom  of  the  vessel  and  burning.  The  melted  fat  is  drained  from  the 
cracklings  by  passing  through  metallic  sieves,  and  cracklings_afterwards 
pressed  in  suitable  presses  to  recover  the  adhering  fat,  which  forms  a  second 
quality  tallow.  A  raw  tallow  yields  on  the  average  eighty  to  eighty-two 
per  cent,  of  drained  oil  and  ten  to  fifteen  per  cent,  of  cracklings ;  a  very  pure 
kidney  fat  will  yield,  however,  ninety  per  cent,  and  over  of  drained  fat. 

In  the  second  process,  now  generally  followed,  to  one  hundred  kilos,  of 
tallow,  twenty  kilos,  of  water  mixed  with  one-half  to  one  and  one-half  kilos, 
of  concentrated  sulphuric  acid  is  added.  The  sulphuric  acid  attacks  and 
destroys  the  cell-membranes  rapidly  when  heated,  and  so  allows  of  the  liber- 
ation of  the  fat.  In  this  process,  as  in  the  last,  provision  must  be  made  for 
preventing  the  escape  into  the  air  of  the  unhealthy  and  offensive  odors  coming 
from  the  melting  of  the  impure  tallow.  The  escaping  vapors  are  in  part 
condensed  and  part  burned  under  the  kettles.  In  the  third  process,  that  of 
melting  by  steam,  the  steam  may  be  directly  introduced  into  the  fat  mass  or 
indirectly  used  by  the  aid  of  coils  of  pipes. 

The  tallow  rendering  by  steam  is  illustrated  in  the  apparatus  of  Wilson, 
shown  in  Fig.  18.  The  steam  enters  through  the  perforated  pipe  6r, 
under  the  perforated  false  bottom.  The  plate  F  having  been  shut  down 
tight  upon  the  opening  E,  the  vessel  is  two-thirds  filled  with  the  tallow  and 
steam  applied.  The  pressure  is  allowed  to  rise  to  three  and  a  half  atmos- 
pheres (fifty-two  and  a  half  pounds  per  square  inch)  and  kept  at  this  for 
some  ten  hours.  The  condensed  water  collects  under  the  false  bottom  and 
can  be  drawn  off  when  necessary.  The  melted  tallow  is  then  run  off  from 
the  stopcocks,  PP,  and  the  cracklings  finally  discharged  through  the 
opening  E. 

Some  acid  may  be  added  to  the  fat  or  in  the  Evrard  process,  instead 
of  acid,  caustic  soda,  which  has  the  advantage  of  combining  with  the 
noxious  volatile  acids  evolved. 

The  extraction  of  lard  takes  place  by  similar  methods  to  those  employed 
for  tallow,  but  at  lower  temperatures  and  more  readily. 

For  the  extraction  of  animal  oils,  like  fish  oils,  the  method  of  boiling  out 
with  water  is  generally  employed,  elevation  of  temperature  and  prolonged 
heating  being  avoided  as  much  as  possible  in  the  case  of  the  finer  medicinal 
oils. 

For  oil-bearing  fruits  and  seeds,  the  methods  of  obtaining  oil,  as  already 
mentioned,  are  expression,  either  cold  or  by  the  aid  of  heat,  and  that  of 
extraction  by  solvents. 

For  the  expression  of  oils,  the  carefully  cleansed  seeds  are  first  crushed  to 
break  the  shells  or  kernels  and  then  ground  to  fine  meal.  The  crushing  is 
done  very  generally  in  oil-seed  mills  of  the  construction  shown  in  Fig.  19, 
where  the  two  stones  or  metal  wheels  are  made  to  revolve  on  a  stone  founda- 
tion on  which  the  oil  seeds  are  placed,  and  from  which  any  excess  of  oil  may 
flow.  A  much  more  perfect  crushing  is  possible  in  this  mill  than  in  those 
in  which  stamps  are  used  They  are  then  slightly  heated  for  the  double 
purpose  of  coagulating  any  plant  albumen  and  making  the  oil  more  liquid. 


56 


INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 


In  the  case  of  the  best  medicinal  or  table  oils  all  heat  is  avoided  and  cold- 
pressed  oils  only  taken.  The  meal  is  then  repeatedly  pressed.  The  result 
of  the  first  pressing  is  often  called  "  virgin  oil,"  and  is  of  better  color  and 
taste  than  the  later  lots.  The  pressing  is  done  chiefly  with  hydraulic 
presses,  as  shown  in  Fig.  20,  although  the  old  wedge  presses  may  still  be 
used  on  a  small  scale.  The  crushed  oil  seed  is  placed  in  woolen  or  cotton 
cloths,  usually  covered  in  by  bags  of  horse-hair,  and  then  placed  between 
the  press-plates.  The  other  process,  that  of  extraction  of  the  oil  by  solvents, 
is  capable  of  yielding  a  much  larger  amount  of  oil  than  pressure,  but  has 

FIG.  19. 


been  more  or  less  opposed  on  several  grounds.  The  solvents  employed  are 
carbon  disulphide  and  petroleum-ether.  The  former  is  the  better  solvent,  is 
used  at  a  lower  temperature,  and  is  easily  recovered  from  the  solution  after- 
wards without  leaving  any  appreciable  odor  adhering  to  the  oil.  It,  how- 
ever, dissolves  coloring  matter  and  resin  from  the  seed  as  well  as  oil,  and  so 
introduces  impurity,  and  when  not  perfectly  pure,  it  leaves  sulphur  impuri- 
ties also  in  the  oil.  The  other  solvent  does  not  dissolve  so  much  coloring 
matter  or  resin,  communicates  no  odor,  and  leaves  no  sulphur  or  other 
residues  in  the  oil,  and  so  can  be  used  for  fine  table  oils,  if  necessary.  It 


KAW  MATERIALS. 


57 


FIG.  20. 


requires  a  higher  temperature,  however,  and,  condensing  on  the  surface  of  water 
instead  of  under  it,  like  carbon  disulphide,  requires  more  complicated  distil- 
ling and  condensing  apparatus.  At  the  present  time  the  carbon  disulphide 
is  more  generally  used.  The  objection  first  urged 
against  the  extraction  of  oil  by  solvents,  that  they 
left  the  oil-cake  valueless  for  cattle  food  because  of 
the  too  complete  extraction  of  the  oil,  is  now  met  by 
the  oil  men,  who  leave  eight  to  ten  percent,  of  fat 
or  oil  in  palm-nut  or  other  oil-cake. 

The  expressed  or  extracted  oils  are  in  many 
cases  in  quite  a  crude  condition,  containing  both  sus- 
pended and  dissolved  impurities  of  various  kinds. 
To  purify  them  for  use,  even  in  soap-making,  some 
treatment  is  generally  necessary.  Often  simple  but 
prolonged  subsidence  suffices  if  the  impurities  are 
only  suspended.  Instead  of  subsidence,  it  may  be 
necessary  at  times  to  use  filtration  through  cotton 
wadding  or  animal  charcoal.  If  both  subsidence 
and  filtration  fail  to  clear  the  oils,  it  is  necessary  to 
adopt  chemical  treatment  as  the  impurities  in  time 
ferment  and  develop  a  permanent  rancidity  or  de- 
terioration of  the  oil.  The  first  process  to  note  is 
that  of  Thenard,  to  add  gradually  one  to  two  per 
cent,  of  sulphuric  acid  to  oil  previously  heated  to 
about  100°  F.  and  mix  by  thorough  agitation.  The 
sulphuric  acid  both  takes  up  the  water  that  holds  the 
impurities  in  solution  and  chars  the  impurities  them- 
selves. The  treatment  with  acid  is  to  be  followed  by 
a  thorough  washing  with  warm  water  and  final  filtra- 
tion. Cogan's  process  follows  the  addition  of  sulphuric  acid  by  that  of  steam. 
Instead  of  sulphuric  acid,  caustic  alkalies  are  sometimes  used  as  in  the  Evrard 
process  (see  p.  55),  which  is  chiefly  applied  to  colza  and  rape  oils.  In  this 
case,  the  caustic  soda  saponifies  a  small  quantity  of  the  oil,  and  the  soap  carries 
down,  mechanically,  all  impurities,  leaving  the  oil  perfectly  clear.  Too  pro- 
longed agitation  may,  however,  make  an  emulsion  of  soap  and  oil,  which 
separates  with  difficulty.  R.  von  Wagner  proposed  the  use  of  zinc  chloride 
instead  of  sulphuric  acid,  as  this  chars  the  impurities  without  attacking  the 
oil.  The  zinc  chloride  is  used  in  concentrated  solution  of  1.85  specific 
gravity,  about  one  and  one-half  per  cent,  being  taken  and  thoroughly  agitated 
with  the  oil.  After  the  zinc  chloride  solution  is  withdrawn,  the  oil  is 
well  washed  with  water  and  filtered.  Tannin  is  also  used  to  clear  some  oils, 
which  it  effects  by  coagulating  the  albumen. 

Cotton-seed  oil  is  always  colored  by  some  resin,  which  is  removed  by 
treatment  with  alkali,  which  saponifies  the  resin  and  the  free  acids  of  the 
crude  oil.  A  recent  patent  proposes  to  replace  the  sodium  hydrate,  which 
in  its  action  causes  a  loss  of  from  three  to  seven  per  cent,  of  the  oil,  by 
sodium  carbonate,  which  is  capable  of  acting  upon  the  coloring  matter, 
although  not  upon  the  oil.  A  subsequent  filtration  through  fuller's  earth 
is  also  recommended. 

Still  more  energetic  methods  for  purifying  oils  are  the  oxidation 
methods,  using  "  chloride  of  lime"  or  bichromate  of  potash,  and  sulphuric 
or  hydrochloric  acids  as  applied  to  palm  oil. 


58  INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 

The  use  of  hydrogen  peroxide  solution  has  recently  been  tried  for  the 
bleaching  of  oils,  with  the  best  of  results.  Four  or  five  per  cent,  of  a  ten 
per  cent,  solution  will  generally  suffice  if  repeatedly  shaken  up  with  the  oil 
to  be  treated. 

Ozone-carriers,  like  ferrous  sulphate  solution,  will  also  bleach  in  the 
presence  of  sunlight.  This  method  is  often  applied  with  linseed  oil. 

n.  Processes  of  Treatment. 

1.  SAPONIFICATION  OF  FATS. — The  composition  of  the  proximate 
principle,  olein,  palmitin,  and  stearin,  which  make  up  the  bulk  of  the 
fats  proper,  was  first  established  by  the  researches  of  Chevreul  in  1823. 
Their  decomposition  can  be  effected  in  a  number  of  ways,  by  the  action  of 
bases  like  the  alkalies  and  some  metallic  oxides,  by  the  action  of  sulphuric 
acid  liberating  the  fatty  acids,  and  by  the  action  of  water  alone,  when  aided 
by  heat  and  pressure. 

Chevreul  at  first  used  alkalies,  patenting  that  process  in  1825,  in  con- 
junction with  Gay-Lussac,  but  this  procedure  was  given  up  already  in 
1831,  when  Ad.  de  Milly  replaced  the  alkalies  by  lime.  This  was  used 
exclusively  for  a  number  of  years,  but  was  followed  in  1854  by  the  inde- 
pendent discovery  of  Tilghman  and  Berthelot  of  the  method  of  decom- 
posing by  the  use  of  hot  water  superheated  by  high  pressure.  Melsens 
also  proposed  the  same  process  substantially  a  little  later.  In  consequence 
of  the  danger  connected  with  the  high  temperature  and  pressure,  this  pro- 
cess is  not  carried  out  any  longer  in  its  original  shape,  but  is  now  replaced 
by  the  "  autoclave"  process,  mentioned  later.  In  1841  Dubrunfaut  found 
that  if  neutral  fats  were  treated  first  with  sulphuric  acid,  and  then  boiled 
with  water,  the  fatty  acids  might  be  distilled  in  an  atmosphere  of  super- 
heated steam  without  decomposition.  This  constituted  the  distillation  pro- 
cess. It  was  extensively  used  in  England.  Wilson  and  Gwynne  found  it 
possible,  with  proper  application  of  the  superheated  steam  and  regulation 
of  the  temperature  (290°  to  315°  C.),  to  dispense  with  the  sulphuric  acid, 
and  to  decompose  the  fats  and  then  distil  them  without  any  decomposition. 
This  process  is  now  used  on  a  large  scale  by  the  Price  Candle  Company  in 
England.  Still  later,  Bock,  of  Copenhagen,  found  that  if  the  membranous 
cellular  tissue  that  enclosed  the  fat  be  decomposed  by  a  preliminary  treat- 
ment with  sulphuric  acid  and  the  charred  tissue,  which  by  oxidation 
becomes  heavier  than  the  fat  and  sinks  through  it,  be  removed,  the  pure 
fat  could  be  decomposed  by  boiling  with  water  in  open  tanks.  The  sepa- 
rated fatty  acids  are  so  pure  in  color  that  washing  suffices,  and  no  distilla- 
tion is  necessary. 

These  several  processes  have  been  in  time  modified  and  amalgamated 
until  now  only  three  or  four  processes  are  practically  followed  on  a  large 
scale  : 

(1)  The  saponification  by  alkalies  used  exclusively  in  soap-making  and 
yielding  a  soda  or  potash  salt  of  the  fatty  acid.     (See  SOAPS,  p.  62.) 

(2)  A  combination  of  the  lime  and  hot-water  processes,  known  as  Milly's 
" autoclave  process"  in  which  two  to  four  per  cent,  of  lime  is  made  to  do 
the  work  of  saponification,  for  which  8.7  per  cent,  is  theoretically  needed, 
and  for  which  fourteen  to  seventeen  per  cent,   was   at   first   used.     The 
saponification  is  carried  out  in  the  presence  of  water  in  strong,  closed, 
metallic  vessels,  at  a  temperature  of  172°  C.     One  form  of  such  vessel  for 


PEOCESSES  OF  TKEATMENT. 


59 


FIG.  21. 


the  saponification  by  lime  under  pressure,  that  of  Leon  Droux,  is  shown  in 
Fig.  21.      At  present  the  form   of  the  vessel  in  use  is  more   generally 

that  of  a  sphere,  which  stands  the 
eight  to  ten  atmospheres  internal 
pressure  better.  The  lime  soap, 
technically  called  "  rock,"  after  its 
separation  is  decomposed  by  sul- 
phuric acid,  four  parts  ^f  acid  to 
each  three  parts  of  lime  used  being 
taken.  After  the  complete  sub- 
sidence of  the  calcium  sulphate  the 
free  fat  acids  are  thoroughly  washed 
with  water  and  steam. 

(3)  The  sulphuric  acid  sapon- 
ification,  followed  by  distillation. 
This  process  is  almost  exclusively 
followed  in  England.  The  amount 
of  sulphuric  acid  used  has  grad- 
ually been  diminished,  as  it  is 
found  that  a  relatively  smaller  per- 
centage will  suffice.  For  offal  fats 
some  twelve  per  cent,  is  now  used, 
for  tallow  nine  per  cent.,  and  for 
palm  oil  six  per  cent.  The  decom- 
position generally  requires  some 
hours  at  a  temperature  varying 
from  120°  to  170°  C.  Milly  mod- 
ified this  process  by  using  a  smaller 
quantity  of  sulphuric  acid  (two  to 
three  and  a  half  per  cent.),  which 
he  allows  to  act  at  a  temperature 
of  150°  C.  for  two  to  three  min- 
utes only,  and  then  boils  with 
water.  In  this  way  the  larger 
portion  of  the  fat  acids  are  white 
enough  to  be  used  for  candle- 
making  without  previous  distil- 
lation, while  some  twenty  per  cent, 
only  of  them  needs  to  be  distilled. 
The  form  of  apparatus  for  the  distillation  of  the  free  fatty  acids  produced 
in  the  sulphuric  acid  saponification  is  shown  in  Fig.  22.  T  is  the  super- 
heater, from  which  steam  at  300°  C.  is  passed  into  the  retort  D,  which  is 
previously  filled  to  three-fourths  of  its  capacity  with  melted  tallow  through 
the  supply-pipes  V  V.  The  fatty  acids  distil  out  of  the  tube  U,  are  con- 
densed by  the  worm  8,  and  collected  by  the  receiver  K. 

(4)  The  superheated-steam  process  of  Wilson  and  Gwynne,  before  al- 
luded to.  This  is  at  present  carried  out  in  both  England  and  Germany. 
The  apparatus  devised  by  Mr.  G.  F.  Wilson,  of  the  Price  Candle  Com- 
pany, of  London,  is  shown  in  Fig.  23.  The  fat,  previously  heated  in  the 
flat  vessel,  A,  by  the  waste-heat  from  the  superheater  below,  flows  into  the 
retort  C.  This  retort  must  be  kept  at  from  290°  to  315°  C.,  and  to  this 
end  is  covered  entirely  above;  the  superheated  steam  at  315°  C.  comes 


60 


INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 


into  the  retort  by  the  tube  to  the  side,  and  some  twenty-four  to  thirty-six 
hours  is  necessary  to  decompose  and  distil  off  a  charge  of  fat.  If  the 
temperature  falls  below  310°  C.,  the  decomposition  is  extremely  slow,  while 
much  above  315°  C.,  acrolein  forms  from  the  decomposition  of  the  glyc- 
erine. Before  proceeding  with  the  special  processes  of  soap-making,  stearine- 


FIG.  22. 


candle  manufacture,  oleomargarine  and  glycerine  production,  it  will  be  well 
to  present  in  schematic  way  the  complete  treatment  of  a  fat  such  as  tallow. 
The  accompanying  scheme  is  taken  from  Post's  "  Chemische  Technologic," 
and  shows  the  processes  applicable  and  the  products  resulting  from  the  tech- 
nical utilization  of  tallow. 

FIG.  23. 

B 


2.  PRACTICAL  SOAP-MAKING. — In  the  application  of  the  first  method 
of  saponification  of  fats,  that  of  the  use  of  alkalies,  we  have,  of  course, 
always  a  potash  or  a  soda  salt  of  the  fatty  acid  formed,  which,  singly  or 
admixed,  constitute  the  products  known  as  soaps.  A  very  great  variety  of 
soaps  are  known,  the  appearance  and  properties  of  which  vary  according 
to  the  method  of  manufacture.  We  may  classify  the  several  methods  of 
manufacture  as  follows : 


PROCESSES  OF  TREATMENT. 


61 


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62  INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 

(1)  Boiling  the  fats  in  open  vessels  (coppers)  with  indefinite  quantities  of 
alkaline  lyes  until  products  of  definite  character  are  gotten.     These  are  (a), 
soft  soaps,  in  which  the  glycerine  is  retained,  potash  being  the  base ;  (6), 
the  so-called  "  hydrated  soaps,"  with  soda  for  a  base,  in  which  the  glycerine 
is  retained,  and  of  which  "  marine"  soap  may  be  taken  as  the  type ;  (c)> 
hard  soaps,  with  soda  for  a  base,  in  which  the  glycerine  is  eliminated,  com- 
prising three  kinds, — curd,  mottled,  and  yellow  soaps. 

(2)  Acting  upon  the  fats  with  the  precise  quantity  of  alkali  necessary  for 
saponification  without  the  separation  of  any  waste  liquor,  the  glycerine  being 
retained  in  the  soap.     This  includes  (a)  soaps  made  by  the  "  cold  process," 
and  (6)  soap  made  under  pressure. 

(3)  Direct  union  of  the  fatty  acids,  as  in  "  red  oil"  and  caustic  alkali,  or 
alkaline  carbonate. 

The  general  outlines  of  these  methods  may  be  indicated : 
In  the  manufacture  of  soft  soaps  the  drying  oils  are  preferably  used. 
In  England  whale,  seal,  and  linseed  oil  are  chiefly  used,  in  Continental 
Europe  hemp-seed,  linseed,  rape-seed,  poppy,  and  train  oils,  and  in  the 
United  States  cotton-seed  oil  and  oleic  acid.  A  potash  lye  containing  some 
carbonate  is  used,  and  frequently  a  portion  of  the  potash  is  replaced  by 
soda.  The  soft  soaps,  after  being  boiled  to  the  necessary  degree,  are  not 
salted,  so  that  the  glycerine  and  any  excess  of  alkali  remains  in  the  soap. 
For  use  in  wool-scouring  this  excess  of  alkali  is,  however,  unsuited,  so 
that  neutral  soft  soaps  are  specially  sought  to  be  obtained.  The  method 
of  making  "  hydrated"  or  "  filled"  soaps  is  very  similar  to  that  of  soft 
soaps.  Fatty  matter  and  soda  lye  are  run  into  the  copper,  and  the  whole 
is  boiled  together,  care  being  taken  to  avoid  an  excess  of  alkali  at  first ; 
when  saponification  has  taken  place,  lye  is  cautiously  added  until  the  soap 
tastes  very  faintly  of  alkali,  when  the  soap  is  ready  to  be  transferred  to  the 
frames,  without  any  salting  or  separating  of  the  mixture.  Marine  soap,  for 
use  with  sea-water,  is  made  in  this  way,  and  is  entirely  cocoa-nut  oil  soap. 
The  well-known  Eschweger  soap  is  also  made  by  this  general  method  from 
a  mixture  of  cocoa-nut  oil  and  other  fats,  saponified  either  separately  or 
together,  and  containing  the  glycerine  and  water  in  the  soap  mass. 

The  manufacture  of  true  hard  soaps,  which  still  constitute  the  great  bulk 
of  those  made  in  England  and  the  United  States,  requires  more  time  and 
care  than  the  varieties  just  mentioned.  Melted  fat  and  a  quantity  of  soda 
lye  of  about  11°  B.,  equal  to  one-fourth  that  needed  for  complete  saponifi- 
cation, are  simultaneously  run  into  the  copper  and  steam  turned  on.  The 
"  soap-copper,"  as  shown  in  Fig.  24,  is  an  iron  kettle,  or  series  of  kettles,  set 
in  masonry,  and  equipped  with  pipes  for  both  open  and  closed  steam,  and 
provided  with  an  outlet  for  the  discharge  of  the  waste  lyes  when  required. 
They  may  be  used  in  series,  or  extra  large  single  ones  used.  Strong  lye 
should  not  be  used  at  this  first  stage,  or  saponification  will  not  take  place. 
When  the  mixture  becomes  homogeneous,  lye  of  20°  to  25°  B.,  in  amount 
equal  to  that  taken  before,  may  be  cautiously  added.  It  is  now  boiled  until 
a  sample  taken  out  has  a  firm  consistence  between  the  fingers.  Common  salt 
or  a  brine  of  24°  B.  is  now  run  in.  A  small  sample  removed  on  a  spatula 
or  trowel  should  now  allow  clear  liquor  to  run  from  it.  The  boiling  is  then 
stopped,  and  the  copper  should  be  allowed  to  stand  at  least  two  to  three 
hours.  The  contents  now  divide  themselves  into  two  portions,  the  upper 
consisting  of  soap-paste,  containing  water,  and  the  lower  consisting  of 
"  spent  lye,"  holding  in  solution  common  salt  and  all  the  impurities  of  the 


PROCESSES  OF  TEEATMENT. 


63 


liquors,  together  with  glycerine.  It  should  contain  no  caustic  soda  and 
no  soap.  After  removing  the  spent  lye  from  below,  the  rest  of  the  caustic 
soda  lye  is  rim  in  and  the  soap  boiled  up  again.  At  this  stage  the  rosin  is 
usually  added  for  rosin  or  yellow  soaps.  The  boiling  is  now  continued  until 
the  frothing  mixture  boils  quietly  and  becomes  clear,  the  process  being  known 
as  "  clear  boiling."  The  copper  is  then  boiled  with  open  steam  and  a  small 
quantity  of  lye  of  12°  B.  allowed  to  run  in  until  the  soap  separates  in 
flakes  and  feels  hard  when  cold,  technically  called  "making  the  soap." 
Boiling  is  still  continued  for  several  hours  to  insure  complete  sapojiification, 
and  it  is  then  allowed  to  separate  and  harden.  This  procedure  yields  a  curd 


soap  if  no  rosin  has  been  added.  If,  after  a  soap  is  "  made,"  the  lye  in 
which  it  is  suspended  is  concentrated  to  a  point  short  of  that  necessary  to 
produce  hard  curd  soap,  and  it  is  then  transferred  to  the  cooling  frames 
with  a  certain  quantity  of  lye  entangled  in  it,  these  insoluble  particles  will, 
during  the  solidification  of  the  soap,  collect  together  and  produce  the  appear- 
ance known  as  "  mottling ;"  and  the  effect  is  heightened  by  the  partial  crys- 
tallization of  the  soap.  The  lye  remaining  in  the  cavities  between  the  curds 
makes  mottled  soaps,  the  most  suitable  and  really  economical  for  washing 
clothes,  etc.,  in  hard  waters,  although  not  for  toilet  purposes.  Mottling  is 
sometimes  added,  as  the  peculiar  greenish  mottle,  which  becomes  red  on 
exposure,  characteristic  of  Marseilles  and  Castile  soaps,  is  produced  by 
adding  some  solution  of  ferrous  sulphate  to  the  copper  when  the  soap  is 
nearly  finished  (about  four  ounces  of  the  salt  to  one  hundred  pounds  of  the 
fat) ;  the  precipitated  iron  protoxide  suspended  in  the  soap  is  greenish,  but  it 
becomes  peroxide  in  contact  with  air,  to  which  the  change  to  a  red  color  on 
exposure  is  due.  Yellow  soaps  are  made  from  tallow  and  rosin,  the  pro- 
portion of  rosin  varying  from  one-sixth  of  the  total  fat  to  an  equal  weight, 
or  even  more,  according  to  the  quality  of  the  soap  desired.  In  the  presence 
of  the  sodium  oleate  from  the  tallow,  the  rosin  acids  saponify  readily  and 
coalesce  to  form  a  very  uniform  soap. 

In  smooth  or  "  cut"  soaps  water  or  thin  lye  is  added  to  the  contents  of 
the  copper  before  the  soap  separates  finally  to  form  the  curd,  and  is  taken 


64  INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 

up  in  considerable  amount,  giving  a  smooth  yet  firm  surface  to  the  soap, 
instead  of  the  hard,  granular  surface  of  the  curd  soap. 

The  so-called  "  cold  process77  requires  the  use  of  exact  weights  of  well- 
refined  fats  and  of  caustic  soda  of  a  given  specific  gravity,  the  quantities 
being  such  that  only  just  enough  soda  is  present  to  completely  saponify  the 
fat.  The  materials  are  allowed  to  stand  together  for  a  short  time  and  then 
thoroughly  mixed  in  a  copper  provided  with  steam,  agitating  paddles,  and 
kept  at  a  temperature  of  not  over  120°  F.  The  reaction  proceeds  rapidly, 
and  after  some  fifteen  minutes  the  materials  have  so  far  united  that  they 
will  not  separate  on  standing,  although  the  complete  saponification  of  the 
materials  may  require  days.  They  are  then  run  out  into  the  cooling-frames. 
It  is  obvious  that  soaps  made  in  this  way  retain  all  the  glycerine  originally 
combined  with  the  fatty  acids  disseminated  through  the  particles  of  soap, 
and  belong  to  the  class  known  as  "  filled77  or  "  padded77  soaps,  mentioned 
before.  (See  p.  62.) 

When  cocoa-nut  oil  alone  is  used,  the  temperature  of  working  in  this  cold 
process  need  not  be  higher  than  75°  F.  for  summer  and  90°  F.  in  winter ; 
if  one-half  tallow,  104°  to  108°  F. ;  and  if  two-thirds  tallow,  113°  to 
120°  F.  is  necessary. 

Mixtures  of  cocoa-nut  oil  and  other  fats  are  frequently  saponified  in  this 
way,  the  free  acid  of  the  cocoa-nut  oil  readily  starting  the  process  of  saponi- 
fication. A  well-refined  tallow  can,  however,  be  saponified  in  this  way  too, 
and  mixtures  of  tallow  and  rosin  worked  up  also  into  yellow  filled  soaps. 

This  combination  of  cocoa-nut  oil  with  tallow  and  rosin  can  also  take 
up  in  its  saponification  large  quantities  of  water-glass  and  similar  "  filling77 
material,  so  that  a  very  large  yield  of  a  smooth  filled  soap  is  obtained. 
Thus  a  mixture  of  one  hundred  kilos,  of  cocoa-nut  oil,  seventy-five  to  eighty 
kilos,  of  rosin,  three  hundred  kilos,  of  water-glass,  one  hundred  to  one  hun- 
dred and  fifty  kilos,  of  tallow,  and  two  hundred  and  forty  kilos,  soda  lye  of 
33°  B.,  will  make  eight  hundred  kilos,  of  a  finished  soap. 

Saponification  under  pressure  has  also  been  frequently  tried,  the  object 
being  to  shorten  the  time  required  for  open  boiling.  In  this  case  the  quan- 
tity of  alkali  used  must  be  accurately  adjusted  to  the  fat  to  be  saponified, 
the  glycerine  is  retained  in  the  ultimate  product.  The  process  is  carried  out 
in  an  autoclave  or  pressure-boiler,  the  temperature  is  alloAved  to  rise  to 
about  310°  F.  (154.4°  C.),  equivalent  to  a  steam-pressure  of  sixty-three 
pounds  to  the  square  inch,  and  kept  at  this  for  an  hour,  when  the  contents 
are  discharged  into  a  cooling-frame. 

There  remains  to  be  noted  the  process  of  soap-making,  in  which  we 
start  not  with  a  fat,  but  with  the  free  fatty  acid,  as  in  the  "  red  oil77  or  crude 
oleic  acid  obtained  in  stearine  candle  manufacture.  (See  p.  67.)  These  oleine 
soaps,  as  they  are  called,  are  made  preferably  from  the  oleic  acid  resulting 
from  the  saponification  of  tallow  or  palm  oil  by  the  lime  process.  That 
obtained  in  the  distillation  process  is  not  so  well  adapted  for  use  here.  The 
oleic  acid  may  be  saponified  either  with  carbonate  or  with  caustic  alkali.  The 
former  process  has  the  disadvantage  that  the  escaping  carbonic-acid  gas  causes 
a  strong  frothing  which  easily  leads  to  boiling  over.  One  hundred  kilos,  of 
the  oleic  acid  obtained  in  the  lime-saponification  yield  one  hundred  and  fifty 
to  one  hundred  and  sixty  kilos,  of  soap.  The  acid  obtained  by  distillation 
always  yields  somewhat  less.  Frequently  the  oleic  acid  before  saponifying 
is  changed  by  nitrous  acid  into  the  isomeric  elaidic  acid,  which  is  as  hard  as 
tallow,  and  from  which  a  very  fine  soap  can  then  be  made  resembling  tallow 


PROCESSES  OF  TREATMENT. 


65 


soap,  and  capable  of  being  worked  at  will  into  a  curd  soap  or  a  cut  soap. 
If  to  be  made  with  carbonate  of  soda,  the  copper  is  filled  to  one-third  its 
capacity  with  the  oleic  acid  and  the  calculated  amount  of  half-crystallized 
and  half-calcined  soda  added,  little  by  little,  while  the  heating  and  thorough 
agitation  of  the  liquid  is  kept  up.  When  the  soap  becomes  thick  and  all  foam- 
ing has  ceased,  the  soap  is  filled  at  once  into  the  forms  to  cool.  The  portion 
of  crystallized  soda  used  supplies  all  the  water  needed  for  the  saponification. 
In  saponification  with  caustic  alkali,  a  strong  lye  (25°  B.)  is  taken. 
No  emulsion  forms,  but  a  lumpy,  mortar-like  mass,  which,  however,  as  the 
alkali  is  more  fully  taken  up  and  the  lye  becomes  weaker,  gradually  goes 
over  into  ordinary  soap-paste.  The  soap  is  separated  by  the  addition  of  a 
strong  lye  instead  of  salting  it. 

After  the  finishing  of  the  soap  in  the  copper,  it  may  either  be  put  direct 
into  the  cooling  frame,  or  it  may  be  transferred  to  mixing  tanks,  where 
various  solutions  or  substances  are  incorporated  with  it  prior  to  its  being 
allowed  to  solidify. 

Soap-frames  are  of  two  kinds,  according  as  it  is  desired  to  cool  the  soap 

slowly     or     quickly. 

-  25.  When  slow  cooling  is 

required,  as  is  always 
the  case  with  mottled 
soap,  wooden  frames, 
usually  of  pine,  are 
employed.  These  are 
built  up  in  horizon- 
tal sections,  nine  to 
twelve  inches  deep, 
each  section  lined  with 
thin  sheet  -  iron,  as 

shown  in  Fig.  25.  Most  curd  and  all  yellow  soaps  are  cooled  rapidly  in 
cast-iron  frames  of  any  desired  shape  and  size.  Such  an  iron  soap-frame  is 
illustrated  in  Fig.  26.  The  sides 
and  ends  of  the  frame  are  easily 
removed  after  the  thorough  so- 
lidification of  the  soap,  and  the 
block  is  then  left  upon  the  truck, 
which  served  as  the  bottom  of  the 
frame."  It  is  now  ready  for  the 
cutting  into  slabs  and  bars.  This 
is  now  almost  universally  done 
by  machinery,  and  the  truck  con- 
taining the  hardened  block  is  run 
at  once  into  the  large  frame  con- 
taining the  cutting  wires.  Such 
a  frame,  although  of  smaller  size, 
and  used  for  slabs  of  soaps  only, 
is  shown  in  Fig.  27.  The  best 
piano-forte  wire  is  necessary  for 
these  cutting  frames,  as  the  tension  is  very  great  when  the  soap  is  pressed 
through  the  wires. 

While  the  soaps  thus  far  spoken  of  are  adapted  for  general  or  laundry 
purposes,  there  is  a  distinct  class  of  soaps  known  as  toilet  soaps.  As  these 

5 


FIG.  26. 


66  INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 

are  to  be  applied  to  the  skin  they  must  answer  other  requirements,  the 
most  important  of  which  is  that  they  shall  not  contain  any  free  alkali. 
Some  dermatologists  even  demand  that  there  shall  always  be  some  un- 
saponified  fat.  We  may  distinguish  transparent  soaps,  remelted  soaps,  and 
milled  soaps. 

Transparent  soaps  may  be  made  either  by  the  spirit  process,  in  which 
case  the  stock  soap  is  dissolved  in  alcohol,  the  solvent  almost  all  distilled 
off,  and  the  mixture  then  run  into  frames  to  gelatinize  and  solidify  by 
gradual  evaporation  of  the  remaining  alcohol,  or  the  cold  glycerine  process. 
In  this  case  the  wrarm  fatty  materials  employed  (of  which  castor  oil  is 
generally  a  large  ingredient  on  account  of  the  readiness  with  which  it 
saponifies)  are  intimately  mixed  with  soda  ley ;  soluble  coloring  matters 
and  essential  oils  or  other  scenting  material  are  then  stirred  in  and  the 
whole  allowed  to  stand.  The  glycerine  which  forms  on  saponification 
tends  to  cause  the  soap  to  take  a  translucent  appearance.  Perfect  trans- 
parency can  be  obtained  by  the  addition  of  more  glycerine,  or  what  accom- 
plishes the  same  result  and  is  cheaper,  cane-sugar.  This  latter  ingredient, 
however,  makes  the  soap  irritating  to  sensitive  skins. 

In  the  remelting  of  soaps,  followed  chiefly  in  England,  several  stock 
soaps  may  be  mixed  together,  coloring  and  scenting  materials  added,  and 
the  mass  heated  in  a  steam-jacketed  pan.  If  the  mixture  is  rapidly 
agitated,  enough  air-bubbles  may  be  worked  in  to  enable  the  cake  of  soap 
to  float  in  water,  even  after  compression  in  the  stamping  press,  producing  a 
toilet  soap  which  "  floats"  on  water.  The  addition  of  some  pearlash  (potas- 
sium carbonate)  is  also  made  at  times  to  improve  the  lathering  power  of 
the  soap,  but  such  soaps  are  alkaline  and  injurious  to  delicate  skins.  The 
finest  toilet  soaps,  however,  are  made  by  "  milling,"  a  process  first  carried 
out  in  France.  The  bars  of  stock  soap  are  first  "  stripped,"  or  cut  into 
slices  by  a  slicing  machine.  The  chips  are  dried  in  a  warm  air-chamber 
until  only  a  few  per  cent,  of  water  remains,  and  then  ground  between 
heavy  horizontal  rollers  of  the  milling  machine.  At  this  stage  the  various 
coloring  and  perfuming  ingredients  are  added,  or  unguents  like  lanolin 
and  vaseline.  The  thoroughly  mixed  material  is  then  put  into  a  cylin- 
drical barrel,  in  which  it  is  compressed  by  a  piston  and  comes  out  as  a 
continuous  bar,  which  is  cut  into  lengths  and  stamped  into  cakes.  The 
advantages  of  this  method  are,  first,  that  inasmuch  as  no  artificial  heat 
is  applied,  delicate  flower  perfumes,  etc.,  can  be  readily  incorporated  with 
the  soap  mass  which  it  would  be  impossible  to  use  with  a  remelted  soap, 
because  the  heat  would  dissipate  or  destroy  the  odoriferous  matter ;  and, 
secondly,  that  as  the  resulting  tablets  usually  contain  only  a  small  quan- 
tity of  water,  a  given  weight  of  soap-cake  or  tablet  generally  contains 
a  much  larger  quantity  of  actual  soap  than  another  cake  of  the  same 
weight  prepared  by  remelting  or  by  the  cold  process,  whilst,  being  harder 
and  stiffer,  it  lasts  longer,  wasting  less  rapidly  during  use.  Spherical 
cakes  and  wash-balls  are  finished  by  turning  and  polishing  in  a  kind  of 
lathe.  Sometimes  the  polishing  is  finished  by  the  use  of  a  cloth  dipped 
in  alcohol. 

Shaving  creams  are  made  by  the  cold  process  from  refined  lard  and 
caustic  potash,  adding  cocoa-nut  oil  in  small  amount  to  facilitate  the 
making  of  lather. 

3.  STEARIC  ACID  AND  CANDLE  MANUFACTURE. — For  the  extrac- 
tion of  stearic  acid,  the  washed  fatty  acids  (see  p.  59)  are  heated  to  the 


PROCESSES  OF  TREATMENT. 
FIG.  27. 


67 


FIG.  28. 


melting  point  and  run  into  dishes  or  troughs  made  of  tin,  as  shown  in  Fig. 

28.      These  are  placed  in  a  room,  the  temperature  of  which  is  kept  at 

68°  to  86°  F.  (20°  to  30°  C.),  and 

left  for  two  to  three  days,  or  until 

the  contents  have  granulated,  as  the 

palmitic  and  stearic  acids  crystallize, 

when  the   dishes  are   emptied  into 

canvas  or  woollen  bags,  which  are 

carefully     deposited     between     the 

plates  of  an  upright  hydraulic  press, 

as  shown  in  Fig.  29.     Pressure  is 

now   exerted,  increasing    in   degree 

until  the  flow   of   the   liquid  oleic 

acid  ceases.     The  hard,  thin  cakes 

of  crude  stearic  acid  so  obtained  are 

then  melted  down  again  with  steam, 

and  after  settling,  the  melted  acid  run 

into  the  tin  dishes  and  placed  aside 

to   cool.     The  temperature   of   the 

cooling-room  in  this  case  should  be 

higher  than  before,  or  about  86°  F. 

(30°  C.).    The  blocks  of  stearic  acid 

gotten  are  ground  to  meal,  filled  in 


bags  of  hair  or  wool,  and  then  sub- 
mitted to  a  second  pressure  in  a  hori- 
zontal hydraulic  press,  the  plates  of  which  can  be  heated.     In  this  press,  a 
pressure  of  six  tons  per  square  inch,  at  temperatures  of  from   104°   to 
120°  F.  (40°  to  49°  C.),  is  reached.     The  cakes  so  obtained  are  melted  by 


68 


INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 


steam,  a  little  wax  being  sometimes  added  to  destroy  the  crystalline  struc- 
ture of  the  stearic  acid,  which  somewhat  unfits  it  for  candle-making. 

The  yield  of  stearic  acid  obtained  varies  according  to  the  fat  used  and 
the  process  of  saponification  employed.  F.  A.  Sarg's  Sons  (Vienna)  use 
three  per  cent,  of  lime  under  a  pressure  of  ten  atmospheres,  and  get 
ninety-five  per  cent,  of  crude  fat  acids  and  thirty  per  cent,  of  glycerine 
water  (5°  to  6°  B.),  and  a  final  yield  of  forty-five  per  cent,  stearic  acid, 
fifty  per  cent,  of  oleic  acid,  and  five  to  six  per  cent,  of  glycerine.  In 
England,  with  the  sulphuric  acid  and  distillation  process,  they  get  sixty  to 
seventy  or  even  seventy-five  per  cent,  of  fat  acids  suitable  for  candle- 
making,  although  inferior  to  that  obtained  in  the  lime  process. 

FIG.  29. 


Palm  oil  is  now  used  in  enormous  quantities  for  the  production  of 
palmitic  acid  at  Price's  Candle  Company's  works,  as  well  as  by  almost 
every  candle  manufacturer  in  Great  Britain,  about  twenty-five  thousand 
tons  being  annually  consumed.  In  many  continental  countries  a  prohibi- 
tive duty  prevents  its  employment.  From  this  palmitic  acid  the  finest 
composite  candles  are  made  by  hot-pressing  the  distilled  palmitic  acid. 

Palmitic  acid  for  candle-making  is  also  made  commercially,  according 
to  a  process  of  St.  Cyr-Radisson,  by  fusing  oleic  acid  with  a  great  excess 
of  caustic  potash,  the  products  of  the  reaction  being  potassium  palmitate, 
potassium  acetate,  and  hydrogen.  As  carried  out  in  Marseilles,  the  oleic 
acid  and  potash  lye  of  41°  B.  are  put  into  an  autoclave  provided  with  a 


^  PROCESSES  OF  TREATMENT.  69 

mechanical  agitator,  and  heated  until  steam  ceases  to  be  given  off,  when  the 
open  manhole  is  closed,  and  the  heat  continued  until  554°  F.  (290°  C.)  is 
reached.  Decomposition  now  commences,  and  much  hydrogen  is  given  off 
through  an  escape-tube  set  in  the  lid  of  the  boiler.  At  608°  F.  (320°  C.) 
the  odor  of  the  evolved  gas  suddenly  changes,  and  destructive  distillation 
begins.  This  is  arrested  by  blowing  in  steam  at  once,  and  the  contents  are 
run  out.  The  potassium  palmitate  is  then  washed,  decomposed  with  sul- 
phuric acid,  the  free  acid  washed  and  distilled.  The  product  of  the  dis- 
tillation is  white,  and  burns  excellently  when  made  into  candles. 

In  the  manufacture  of  candles,  the  first  operation  is  the  preparation  of 
the  wick.  For  dip-candles  the  wick  is  twisted,  for  others  it  is  plaited,  and 
the  kind  of  plaiting  must  also  vary  according  to  the  material  used. 
Stearine  candles  require  a  moderately  tightly-braided  wick,  paraffine  candles 
an  extra  tight  braid,  and  for  spermaceti  and  wax,  on  the  other  hand,  the 
braids  are  measurably  loose.  After  being  twisted,  or  plaited,  the  wicks  are 
dried  and  then  dipped  into  a  pickling  liquor,  which  is  to  retard  combustion 
and  help  in  the  destruction  of  the  ash.  The  pickle  usually  consists  of  a 
solution  of  boracic  acid,  ammonium  phosphate,  or  ammonium  chloride.  Three 
plans  of  candle-making  are  at  present  in  use, — dipping,  moulding,  and 
pouring.  The  first  is  employed  for  common  tallow  candles,  which  are 
accordingly  called  "  dips."  Under  a  frame  holding  the  suspended  wicks  are 
placed  troughs  containing  melted  tallow,  into  which  the  wicks  are  repeatedly 
dipped.  After  each  dipping  the  adherent  fat  is  allowed  to  cool  sufficiently 
to  retain  a  fresh  coating  on  immersion.  When  the  candles  have  thus^ 
grown  to  the  proper  thickness  they  are  left  to  cool  and  harden.  These- 
cheap  "  dips"  are,  however,  now  being  replaced  by  small,  moulded  "  com- 
posite" candles,  as  well  as  candles  made  from  the  softer,  paraffine  scale. 
Pouring  is  used  only  with  wax  candles,  which  cannot  be  moulded  because 
of  the  adhering  or  cracking  of  the  wax  in  removing  it  from  the  moulds. 
A  well-made  wax  candle  should  show  rings  like  a  tree,  where  the  different 
layers  have  been  superposed.  By  far  the  greater  number  of  candles  are 
moulded,  by  which  process  they  acquire  a  much  more  finished  appearance. 
A  form  of  frame  in  common  use  is  represented  in  Fig.  30. 

The  materials  in  general  use  for  candle-making  are  tallow,  palmitic 
and  stearic  acids,  paraffine,  ozokerite  or  ceresine,  spermaceti,  and  beeswax. 
Very  generally,  several  of  these  materials  are  admixed.  Stearic  candles 
have  a  small  quantity  of  paraffine  added  to  obviate  the  crystalline  structure 
of  the  stearic  acid ;  paraffine  candles  always  have  five  to  ten  per  cent,  of 
stearic  acid  in  them,  to  prevent  the  softening  and  bending  of  the  paraffine 
when  warmed.  Spermaceti  and  beeswax  are  more  expensive  than  the 
other  materials,  and  are  only  used  now  for  special  purposes,  as  for  church- 
candles  and  carriage-lights.  Ozokerite  gives  the  paraffine  candle  of  highest 
fusing  point,  being  some  six  degrees  higher  than  any  other  variety  of  paraffine. 
Colored  paraffine  candles  are  made  by  dissolving  the  coloring  matter  (vege- 
table or  aniline  dyes,  not  mineral  colors)  in  stearic  acid,  and  then  mixing  this 
with  the  paraffine,  which  itself  does  not  take  up  the  color.  Paraffine  and 
other  transparent  candles  must  be  filled  in  the  mould  very  hot,  and  after  all  air- 
bubbles  have  escaped,  the  moulds  must  be  rapidly  cooled  by  a  large  flush  of  cold 
water  to  prevent  the  paraffine,  etc.,  from  crystallizing  and  thus  causing  opacity, 

Of  interest  in  this  connection  is  the  table  of  illuminating  equivalents,  or 
quantities  of  different  illuminating  materials  necessary  to  produce  the  same 
amount  of  light,  prepared  by  Frankland. 


70 


INDUSTRY  OF  THE  FATS  AND   FATTY   OILS. 


Young's  paraffine  oil  .  .  .  .  1.00  gallons. 
American  petroleum,  No.  1  .  1.26  gallons. 
American  petroleum,  No.  2  .  1.30  gallons. 
Paraffine  candles 18.60  pounds. 


Sperm  candles 22.90  pounds. 

Wax  candles        26.40  pounds. 

Composite  (stea^ine)    .    .    .   .29.50  pounds. 
Tallow 36.00  pounds. 


4.  OLEOMARGARINE,  OR  ARTIFICIAL  BUTTEP,  MANUFACTURE. — 
The  manufacture  of  a  butter-substitute  from  the  solution  of  palmitin  in 
olein,  which  is  known  as  oleomargarine,  is  a  fat  industry,  but,  because  of 
its  close  relations  to  natural  butter  made  from  cows'  milk,  it  will  be 


FIG.  30. 


considered  as  supplementary  to  the  description  of  butter  under  milk  indus- 
tries.    (See  p.  256.) 

5.  GLYCERINE  MANUFACTURE. — For  many  years  after  the  development 
of  the  soap  and  candle  industries,  no  attempt  was  made  to  recover  the 
glycerine  which  was  liberated  in  the  saponification.  Its  applications  in 
medicine  and  for  technical  purposes  have  made  it  important  to  extract  and 
purify  it,  however,  and  it  has  now  assumed  almost  equal  importance  with 
the  other  fat  constituents.  The  two  methods  of  saponification,  by  which 
glycerine  has  been  obtained  on  a  large  scale,  are  the  process  of  Wilson  & 
Payne,  of  decomposing  the  fats  by  superheated  steam  and  after  distillation 
(see  p.  59),  and  the  lime  autoclave  process  of  Milly.  (See  p.  58.)  In  the 
distillation  process,  moreover,  by  suitable  arrangement  for  fractional  conden- 
sation, it  is  found  possible  to  concentrate  the  aqueous  glycerine  in  the  process 
of  distillation.  Care  must  be  taken  that  the  temperature  of  600°  F.  (315° 
C.)  is  not  exceeded,  and  that  plenty  of  steam  is  present,  otherwise  some 
glycerine  is  decomposed  and  acrolein  is  formed.  In  the  Milly  process,  after 


PROCESSES  OF  TREATMENT.  71 

the  decomposition  of  the  fat  is  completed  in  the  autoclave,  the  contents  are 
blown  out  into  a  tank  and  the  "  sweet  water"  (glycerine)  is  run  off:  The 
concentrating  may  be  done  in  contact  with  air  or  the  apparatus  may  be 
worked  in  a  Yaryan  or  similar  evaporator.  Evaporation  is  continued  to 
26°  B.  (1.220  specific  gravity),  when  the  glycerine  is  of  a  brownish  color, 
and  is  known  as  u  raw,"  in  which  state  it  is  sold  for  many  purposes,  and 
contains  about  ninety  per  cent,  of  glycerine  and  traces  only  of  mineral 
impurities.  At  Price's  Candle  Company's  works  the  further  purifica- 
tion is  conducted  as  follows.  The  raw  glycerine,  specific  gravity  1.240  to 
1.245,  is  heated  in  a  jacketed  pan  with  that  kind  of  animal  charcoal  known 
as  ivory-black,  and  is  then  distilled ;  this  alternate  treatment  is  repeated  as 
often  as  is  necessary.  The  distillation  is  performed  with  superheated  steam 
in  a  copper  still  provided  with  copper  fractional  condensers,  the  still  being 
also  heated  externally ;  the  operation  is  performed  at  as  low  a  temperature 
as  is  consistent  with  distillation,  usually  about  440°  F.  (227°  C.). 

It  is  obvious  that  in  soap-making,  as  enormous  quantities  of  the  fats  are 
decomposed,  corresponding  quantities  of  glycerine  go  into  the  spent  lyes.  It 
is  only  very  recently  that  it  has  been  attempted  to  recover  this  glycerine, 
and  no  perfectly  satisfactory  process  seems,  as  yet,  to  have  been  adopted. 
More  practical,  in  the  opinion  of  those  qualified  to  judge,  seems  to  be  the 
idea  recently  put  forward  to  deglycerinize  all  fats  before  saponifying  them. 
The  process  of  Michaud  Freres,  of  Paris,  as  carried  out  by  the  Continental 
Glycerine  Company,  of  New  York,  realizes  this  idea  very  successfully. 

According  to  their  patent  "  the  fatty  matter  is  subjected  in  a  close  vessel 
to  the  action  of  the  steam,  at  a  pressure  of  one  hundred  to  one  hundred  and 
thirty  pounds  per  square  inch,  and  at  corresponding  temperature  in  presence 
of  one-fourth  to  one-third  part  its  weight  of  water  and  one-fifth  to  three-fifths 
per  cent,  of  its  weight  of  the  oxide  of  zinc,  known  commercially  as  zinc  white, 
or  a  like  proportion  of  zinc  powder  or  zinc  gray,  which  is  a  residue  in  the  treat- 
ment of  zinc,  being  a  mixture  of  zinc  with  its  oxide.  .  .  .  The  very  small  pro- 
portion of  mineral  substance  used  is  sufficient  for  dispensing  with  the  acid 
treatment  applied  for  decomposing  lime  soap,  and  the  product  obtained,  con- 
sisting almost  exclusively  of  acid  fat,  can  be  converted  by  the  acids  usually 
employed  into  soap  or  candles.  In  soap-making,  the  dissolving  powers  of 
the  caustic  alkalies  remove  all  objections  to  the  presence  of  the  zinc  if  it 
should  be  used  in  excess.  The  reducing  power  of  the  zinc  powder  prevents 
discoloration  of  the  acid  fats  such  as  results  from  the  ordinary  treatment." 
The  glycerine  thus  produced  finds  a  ready  sale,  as  it  runs  from  the 
evaporators,  and  from  it,  as  "  crude,"  ninety-six  per  cent,  of  pure  glycerine 
can  be  obtained. 

5a.  NITROGLYCERINE  AND  DYNAMITE. — In  1847  Sobrero  discovered 
a  very  interesting  derivative  of  glycerine,  and  in  1862  A.  Nobel  gave  it  to 
the  world  as  a  technical  product  of  the  greatest  importance.  When  strong 
glycerine  is  gradually  added  to  a  well-cooled  mixture  of  very  strong  nitric 
and  sulphuric  acids,  it  is  converted  into  glyceryl  nitrate,  or  nitro-glycerine. 
For  the  manufacture  of  nitro-glycerine  on  a  large  scale,  Nobel  recommends 
that  one  part  of  good  glycerine  be  allowed  to  flow  in  a  thin  stream  into 
a  well-cooled  mixture  of  four  parts  of  concentrated  sulphuric  acid  and  one 
part  of  the  very  strongest  nitric  acid  (1.52  specific  gravity),  the  mixture  being 
contained  in  a  wooden  vessel  lined  with  lead.  Means  should  be  provided  by 
which  the  mixture  can  at  once  be  run  into  a  large  quantity  of  water  should  the 
action  threaten  to  become  too  violent.  On  standing,  the  nitro-glycerine  sepa- 


72 


INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 


rates  as  a  layer  on  the  surface  of  the  acid,  and  is  skimmed  off  and  washed 
with  water  and  solution  of  sodium  carbonate  to  get  rid  of  every  trace  of  free 
acid.  Or,  according  to  the  same  authority,  a  mixture  is  made  of  one  part 
nitre  with  3.5  parts  of  sulphuric  acid  (1.83  specific  gravity),  the  mixture 
cooled  to  32°  F.  (0°  C.),  and  the  liquid  poured  off  from  the  acid  potassium 
sulphate,  which  separates  out ;  into  this  liquid  the  glycerine  is  slowly  dropped, 
the  mixture  poured  into  water,  and  the  separated  nitro-glycerine  washed 
thoroughly  and  dried.  The  yield  is  two  hundred  and  twenty-three  per 
cent,  of  the  glycerine  used. 

It  has  been  suggested  to  mix  the  glycerine  beforehand  with  the  sulphuric 
acid,  and  then  run  this  mixture  into  the  nitric  acid,  and  it  is  claimed  that 
the  elevation  of  temperature  is  less  than  when  the  ordinary  method  is  fol- 
lowed ;  but  the  process  does  not  seem  to  have  been  satisfactory  in  practice 
when  tried  in  England. 

When  absorbed  by  infusorial  earth,  "  kieselguhr,"  sawdust,  mica  powder, 
or  other  inert  porous  material,  nitro-glycerine  forms  the  different  varieties 
of  dynamite,  and,  when  combined  with  gun-cotton,  it  constitutes  the  explosive 
known  as  "  blasting  gelatine." 

m.   Products. 

1.  PURIFIED  OILS,  FATS,  AND  WAXES,  AND  PRODUCTS  FROM  THE  SAME. 
— Most  of  the  important  oils,  fats,  and  waxes  have  already  been  described  as 
raw  materials,  and  the  methods  of  purifying'  them  have  been  noted.  The 
purified  oils  are  in  some  cases  the  final  products  sought,  and,  in  some  cases, 
only  improved  raw  materials  for  the  main  industries,  like  soap-making,  candle- 
making,  and  glycerine  extraction.  These  purified  oils  having,  therefore,  been 
referred  to  as  raw  materials,  will  not  be  further  noted.  A  number  of  side- 
products,  obtained  with  or  produced  from  these  oils,  remain  to  be  mentioned. 

One  of  these  minor  products  of  great  value  is  the  oil-cake,  or  compacted 
mass  of  crushed  seeds  or  nuts,  from  which  the  oil  has  been  expressed  or 
extracted.  This  contains  all  of  the  woody  fibre  and  mineral  matter  of  the 
seed  or  nut,  the  residue  of  oil  or  fatty  matter  not  extracted,  and,  what  gives 
it  special  value,  the  proteids  or  nitrogenous  constituents.  The  oil-cake  thus 
becomes  a  most  valuable  cattle  food  and  a  basis  for  artificial  fertilizers.  The 
following  table  gives  the  composition  of  a  number  of  the  most  important 
oil-cakes : 


Water. 

Fat. 

Non-Nitrogen- 
ous Materials. 
Woody  Fibre. 

Ash. 

Protein 
Material. 

Nitrogen. 
Per  Cent. 

Earth-nut  cake 

11.50 

8.80 

31.10 

7.25 

41.35 

6.80 

Cotton-seed  cake 

13.00 

7.50 

61.00 

8.50 

2000 

2.90 

Rape-oil  cake    . 

10.12 

9.23 

41.93 

6.48 

31.88 

5.00 

Colza-oil  cake  . 

11.35 

900 

42.82 

6.28 

30.55 

4.50 

Sesame-oil  cake 

10.35 

10.10 

38.80 

9.80 

31.93 

5.00 

Beech-nut  cake 

11,40 

8.50 

49.80 

5.30 

24.00 

3.20 

Linseed  cake     . 

1056 

9.83 

44.61 

6.50 

28.50 

4.25 

Camelina  cake  . 

9.60 

9.20 

50.90 

7.00 

23.30 

3.60 

Poppy-oil  cake 
Sunflower-oil  cake 

9.50 
10.20 

890 
8.50 

37.67 
48.90 

11.43 
11.40 

32.50 
21.00 

5.00 
240 

Hempseed  cake 

10.00 

8.26 

48.00 

12.24 

21.50 

3.30 

Palm-nut  cake  . 

9.50 

8.43 

40.95 

10.62 

30.40 

4.50 

Cocoa-nut  cake 

10.00 

9.20 

40.50 

10.50 

30.00 

4.50 

PEODUCTS.  73 

It  will  be  seen  in  this  table  that  they  vary  in  proteids  or  flesh-forming 
constituents  quite  widely.  All  of  these  cakes,  however,  are  too  rich  in  these 
proteids  and  in  fats  to  be  used  unmixed  as  fodder.  They  are,  in  practice, 
mixed  with  cereals,  hay,  and  straw,  and  then  constitute  a  valuable  food. 
The  ash  is,  moreover,  very  rich  in  phosphoric  acid  and  in  potash,  and  this 
explains  its  value  for  fertilizer  manufacture. 

Thus  it  is  stated  that,  as  a  fertilizer,  one  ton  of  cotton-seed-hull  ashes  has 
as  much  value  as  four  and  one-half  of  average  hard-wood  ashes,  _or  fifteen 
of  leached  hard-wood  ashes. 

The  amount  of  oil-cake  obtained  from  the  expression  of  the  different 
vegetable  oils  is  enormous.  Thus  it  is  stated  that  one  ton  of  hulled  cot- 
ton-seed (constituting  forty  per  cent,  of  the  raw  cotton)  will  yield  eight 
hundred  pounds  of  cotton-seed  cake  and  forty-five  gallons  of  crude  cotton- 
seed oil.  The  amount  of  crude  cotton-seed  annually  obtained  in  the  United 
States  is  estimated  at  four  thousand  million  pounds,  half  of  which  only  is 
required  for  sowing. 

The  accompanying  table,  prepared  by  Grimshaw,  will  show  how  thor- 
oughly the  cotton-seed  is  now  utilized  : 

Cotton-seed,  2000  pounds. 


Meats,  1089  pounds.          Lint,  20  pounds.  Hulls,  891  pounds. 


Cake, 
800  pounds. 

Meal. 

Crude  oil, 
289  pounds. 

i 

Fibre.                                Bran. 

i  — 

High-grade              Fuel, 
paper. 

Ashes. 
Fertilizer. 

Summer 
yellow. 

Soap  stock. 

1 

Salad  oil 

Summer 
Lard 

Soap. 

white- 

Winter 
yellow. 

Cotton-seed 
stearine. 

Cottoline 
Miners'  o 

il 

Cattle 
food. 


An  important  manufactured  oil  is  what  is  known  as  "  Turkey-red  oil," 
used  in  the  process  of  alizarin  dyeing.  (See  p.  487.)  There  are,  in  fact,  two 
entirely  distinct  oils  known  under  this  name.  One  is  simply  an  inferior  grade 
of  olive  oil,  that  known  as  "  Gallipoli  oil,"  and  for  this  particular  use  is  pre- 
pared from  somewhat  unripe  olives,  which  are  steeped  for  some  time  in  boil- 
ing water  before  being  pressed.  This  treatment  causes  the  oil  to  contain  a 
large  proportion  of  extractive  matter,  and  hence  it  soon  becomes  rancid. 
This  preparation  has  long  been  used  in  the  old  process  of  Turkey-red  dye- 
ing, under  the  name  Jiuile  tournante.  The  other,  used  for  producing  alizarin 
reds  by  the  quick  process,  is  the  ammonium  salt  of  sulpho-ricinoleie  acid 
(Ci8H33(HSO3)O3),  a  body  which  is  obtained  mixed  with  unaltered  glycerides 
and  with  products  of  its  decomposition  by  the  action  of  sulphuric  acid  upon 
castor  oil. 

From  linseed  oil,  as  the  most  important  of  the  class  of  drying  oils,  is 
prepared  a  product  of  great  value  for  paint  and  varnish  manufacture.  (See 
p.  101.)  What  is  called  "  boiled  oil"  is  linseed  oil,  which  has  been  heated  to 
a  high  temperature  (130°  C.  and  upward),  while  a  current  of  air  is  passed 
through  or  over  the  oil,  and  the  temperature  increased  until  the  oil  begins  to 
effervesce  from  evolution  of  products  of  decomposition.  By  adding  litharge, 
red-lead,  ferric  oxide,  or  manganese  dioxide,  or  hydrate,  during  the  process 


74 


INDUSTRY   OF   THE   FATS   AND   FATTY   OILS. 


of  boiling,  the  oxidation  and  consequent  drying  of  the  product  are  still 
further  facilitated.  The  nature,  proportion,  and  mode  of  adding  these 
substances  are  usually  kept  jealously  secret.  Lead  acetate  and  manganous 
borate  are  among  the  most  approved.  The  action  of  some,  at  least,  of 
these  "dryers"  (e.g.,  compounds  of  manganese)  seems  to  be  that  of  car- 
riers of  oxygen,  while  litharge  dissolves  in  the  oil  and  acts  partly  as  a 
carrier  of  oxygen  and  partly  as  the  base  of  certain  salts  which  oxidize  very 
rapidly. 

Many  of  the  fatty  oils  and  notably  some  of  the  non-drying  oils  are 
capable  of  being  thickened  and  increased,  especially  in  specific  gravity  and 
viscosity,  by  having  a  stream  of  air  blown  through  them.  The  products 
of  this  treatment  are  known  as  blown  oils  or  oxidized  oils.  They  are  not 
resinified  as  when  the  drying  oils  are  boiled  with  driers,  but  become  thick 
and  viscid  like  castor  oil.  This  property  is  taken  advantage  of,  therefore, 
in  the  production  of  heavy  viscid  products,  which  are  used  in  admixture 
with  mineral  oils  for  the  purpose  of  preparing  lubricants  for  heavy  ma- 
chinery. While  cotton-seed,  rape,  olive,  earth-nut,  lard,  and  linseed  oils 
have  all  been  utilized  in  this  way,  the  two  most  commonly  employed  are 
rape  and  cotton-seed  oils. 

In  carrying  out  the  blowing  operation,  the  oil  is  usually  heated  to  70° 
C.  (138°  F.)  or  slightly  more,  and  air  is  then  blown  in  through  a  vertical 
pipe  which  passes  down  nearly  to  the  bottom  of  the  kettle,  the  air  being 
itself  heated  to  the  same  temperature.  In  a  short  time  the  oil  begins  to 
oxidize  and  the  temperature  to  rise.  The  steam  is  then  shut  off  from 
the  heating  coils,  and  care  must  now  be  taken  that  the  temperature  does 
not  rise  above  80°  C.  (176°  F.).  The  process  usually  lasts  from  twelve  to 
forty-eight  hours,  according  to  the  nature  of  the  oil  being  treated  and  the 
character  of  the  product  desired.  By  continuing  the  operation,  products 
may  be  obtained  of  specific  gravity  as  high  as  from  .985  to  .999  even. 

Blown  oils  vary  in  color  from  a  clear  yellow  to  a  dark  reddish  yellow, 
and  have  a  peculiar  and  somewhat  disagreeable  odor.  They  are  very 
viscous,  as  dense  or  denser  than  castor  oil,  from  which  they  differ  in  not 
being  readily  soluble  in  alcohol  but  in  being  soluble  in  petroleum  spirit. 
Their  perfect  miscibility  with  heavy  mineral  oils  is,  however,  their  chief 
advantage.  The  percentage  of  free  fatty  acids  is  usually  increased  by  the 
blowing  operation  and  the  percentage  of  insoluble  fatty  acids  decreased, 
owing  to  the  formation  of  soluble  oxyacids. 

The  following  table  from  Lewkowitsch  ("  Oils,  Fats,  and  Waxes,"  2d 
ed.,  p.  734)  will  show  the  change  undergone  by  rape  oil  in  consequence  of 
the  blowing  operation  : 


Specific 
gravity 
at  15.5°  C. 

Free  acid 
as  oleic. 

Saponifi- 
cation 
value. 

Iodine 
value. 

Insoluble 
acids. 

Soluble 
acids. 

Rape  oil  .  .  . 

0  9141 

5  10 

173  9 

100  5 

94  76 

0  52 

Same,  5  hours'  blowing  . 
Same,  20  hours'  blowing 

0.9275 
0.9615 

5.01 
7.09 

183 
194.9 

88.4 
63.2 

85'.  94 

10.02 

2.  SOAPS. — In  noting  the  processes  for  practical  soap-making,  the  follow- 
ing classes  of  soaps  were  indicated:  (1)  compact  soaps,  including  (a)  curd 
soaps,  (b)  mottled  soaps,  and  (c)  yellow  soaps  ;  (2)  smooth  or  cut  soaps ;  (3) 
filled  or  padded  soaps ;  and  (4)  soft  or  potash  soaps. 


PRODUCTS. 


75 


The  most  important  difference  between  the  compact,  cut,  and  filled  soaps 
is  the  amount  of  water  present  in  the  soap.  In  the  compact  soap  it  may 
vary  from  ten  to  twenty-five  per  cent.,  in  the  cut  soap  from  twenty-five  to 
forty-five  per  cent.,  and  in  the  filled  soap  from  forty-five  to  seventy-five 
per  cent.  In  addition,  the  filled  soap  contains  the  glycerine,  spent  lye,  and 
other  impurities  of  the  soap  copper. 

The  following  table  of  analysis,  by  Mr.  C.  Hope,  as  quoted  by  Allen,* 
will  illustrate  the  composition  of  a  variety  of  soaps  belonging  to  these  sev- 
eral classes  : 


NAME  OF  SOAP. 

MATERIALS. 

Fatty  and  resin  an- 
hydrides. 

§ 

a 

48 

i 

j! 

4 

u 

53 

& 

S 

i 

Sodium  carbonate 
and  hydrate. 

Neutral  salts,  lime, 
and  iron  oxide. 

£ 

1 

1 

White  No  1         .  . 

Tallow                        .      .  . 

69.06 
60.50 
55.71 
44.27 

71.30 

49.95 
71.20 
62.66 
59.28 
38.89 
59.92 
42.41 
60.69 
48.20 
39.92 
63.06 
10.90 
19.42 

8.98 
6.82 
6.90 
6.23 

7.98 

7.00 
7.58 
7.27 
6.65 
5.76 
6.76 
4.14 
7.22 
5.00 
4.70 
7.25 
1.36 
3.11 

.01 
.06 
.03 

7.02 

1.07 

2.34 
.06 
.06 
.42 
6.40 
.02 
5.64 
.04 
.42 
.62 
.02 
.03 
9.00 

2.36 
,48 

1.01 
.03 
.03 
.01 
1.29 

1.59 

'.18 
.25 

3.98 

.27 
.06 
.92 
.75 

.75 

.33 
.22 
.77 
.39 
1.62 
.92 
2.76 
.10 
.15 
.20 
.10 
Trace 
3.00 

.72 
.39 
.26 
1.00 

.82 

1.01 
1.03 
1.22 
.76 
2.53 
1.70 
.51 
.60 
.90 
1.81 
1.90 
3.27 
5.64 

21.14 
32.20 
36.54 
38.14 

17.44 

38.18 
19.70 
28.20 
32.35 
38.70 
31.30 
42.88 
31.22 
45.00 
52.40 
27.47 
84.00 
53.32 

100.18 
100.03 
100.36 
99.77 

99.84 

99.82 
99.82 
100.21 
99.86 
95.19 
99.75 
99.93 
100.00 
99.80 
99.90 
100.00 
99.56 
97.47 

White  No  2  

Tallow  and  cocoa-nut  oil  .  . 
Tallow  and  cocoa-nut  oil  .  . 
Tallow  and  cocoa-nut  oil  .  . 
Tallow,  rosin,  and  cotton- 
seed oil     
Tallow,  rosin,  and  cotton- 
seed oil              .  .         . 

White  No  3            ... 

White  No  4 

Cold  water  No  1       . 

Cold  water  No  2    

Olive  oil  No  1     

Olive  oil             

Marseilles   No  1 

Chiefly  olive  oil   
Palm  oil 

Palm  oil,  No.  1  
Mottled 

Palm-nut  oil      

Satinet     

Tallow  and  rosin  

Glasgow  almond  
Pale  Rosin  No  1 

Tallow  and  rosin  

Tallow  and  rosin 

Pale  Rosin  No  2           .  . 

Tallow  and  rosin  . 

Pale  Rosin  No  3 

Tallow  and  rosin 

Milling       ' 

Not  mentioned  

Yellow  (for  foreign  markets) 
Marine  (for  emigrants)    .  . 

Not  mentioned                  .  . 

Palm-nut  oil  *  * 

Two  of  these  samples,  those  designated  as  "mottled"  and  "marine,"  were 
prepared  by  the  "  cold  process"  (see  p.  64),  which  accounts  for  the  totals 
being  appreciably  less  than  100.00,  as  the  glycerine  was  retained  in  the 
soap. 

The  chief  soaps  of  pharmacy,  as  analyzed  by  M.  Dechan,f  are  composed 
as  follows : 


i 

a 

*    . 

| 

« 

DESCRIPTION  OF  SOAP. 

1 
'3 

| 

3 

|| 

2 

30' 

| 

ll 

03 
S 

1 

J3  ° 

i| 

1 

5*0 

£ 

8 

£ 

GO 

CO 

e~ 

G  ^ 

Hard  soap  (sapo  durus)  .    .    . 
White  Castile  soap  (s.  Cast.  alb.  ) 
Mottled  Castile  soap    .... 

81.5 
76.7 
68.1 

9.92 
9.14 
8.9 

.08 
.09 
.19 

.00 
.00 
.15 

.28 
.36 
.63 

0.20 
0.90 
0.80 

10.65 
13.25 
21.70 

0.50 
0.60 
1.30 

Tallow  soap  (sapo  animalis)   . 

78.3 

9.57 

.28 

.00 

.47 

0.40 

12.50 

1.10 

Soft  soap  (sapo  mollis)     .    .    . 

48.5 

12.6 

.38 

.17 

.93 

1.00 

39.50 

1.60 

*  Allen,  Commercial  Organic  Analysis,  2d  ed.,  vol.  ii.  p.  272. 
f  Pharmaceutical  Journal  [3],  xv.  p.  870. 


76  INDUSTRY  OF  THE  FATS  AND   FATTY  OILS. 

Toilet  soaps  do  not  differ  in  essential  composition  from  the  best  of  com- 
pact and  cut  soaps,  as  given  above,  but  they  are  perfumed  and  given  small 
additions  of  cosmetic  or  hygienic  preparations.  They  are  prepared  in  one 
of  three  ways :  (1),  by  a  melting  of  plain  soaps ;  (2),  a  cold  perfuming  and 
pressing  of  finely-divided  plain  soaps ;  and  (3),  direct  preparation  from  the 
raw  soap-making  materials. 

Transparent  soaps  are  obtained  by  dissolving  the  soaps  in  alcohol  and 
drying  the  solution  in  moulds, — a  slow  process. 

Glycerine  soaps  are  obtained  by  dissolving  the  soaps  in  glycerine  by  the 
aid  of  heat.  The  glycerine  imparts  a  strength  to  the  lather. 

3.  CANDLES. — The  candle-making  materials  have  already  been  enumer- 
ated.    (See  p.  69.)     Tallow   and  wax   candles  were   the   earliest   in   use. 
Stearine  candles,  known  also  under  the  name  of  Milly  candles,  from  the 
French  inventor  of  several  of  the  processes  of  saponification,  came  into  use 
in  1831.     About  the  same  time  paraffine,  first  obtained  in  quantity  from 
bituminous  shales,  and  later  from  ozokerite  and  petroleum,  was  used  for 
candle-making.     These   are  also  known  under  the  name  of  "Belmontin 
candles,"  from  the  locality  of  the  J.  C.  &  J.  Field  candle- works,  in  London. 
Candles  of  mixed  stearic  acid  and  paraffine,  under  the  name  of  Stella  or 
Apollo  candles,  were  then  manufactured.     The  Galician  ozokerite  is  also 
purified  by  sulphuric  acid,  and  under  the  name  of  ceresine  (see  p.  31)  is 
used  in  Austria  for  candle  manufacture.    Beeswax  and  spermaceti,  as  before 
stated,  are  high-priced  materials,  and  are  used  for  special  classes  of  candles. 
The  paraffine  and  stearine  candles  and  those  which  are  mixtures  of  these 
materials  are  now  most  generally  in  use. 

4.  OLEOMARGARINE  OR  BUTTERINE.     (See  p.  256.) 

5.  GLYCERINE   AND   NITRO-GLYCERINE.  —  The   chemical  compound 
which  is  liberated  along  with  the  fatty  acids  when  the  fats  are  saponified  by 
any  of  the  various  processes  already  narrated  is  a  triatomic  alcohol,  called 
glycerine.     When  purified  and  made  absolute,'  it  is  a  colorless,  viscid  liquid, 
without  odor,  but  with  a  pronounced  sweet  taste.     The  specific  gravity  of 
the  absolute  glycerine  is  about  1.266  at  15°  C.     When  kept  for  a  long  time 
at  0°  C.,  rhombic  crystals  are  formed,  their  production  being  greatly  facili- 
tated by  the  presence  of  a  ready-formed  crystal.     The  crystals  are  hard  and 
gritty,  but  deliquescent.     It  boils  under  ordinary  pressure  at  290°  C.,  not 
without   decomposition.     It  is   highly  hygroscopic,  and  is  miscible  with 
water  in  all  proportions.     Glycerine  is  miscible  with  alcohol  in  all  propor- 
tions, but  is  insoluble   in   chloroform,    benzene,  petroleum  spirit,  carbon 
disulphide,  or  fixed  oils.     Glycerine  is  nearly  insoluble  in  ether,  from  which 
it  separates  any  alcohol  or  water.     When  glycerine  is  heated  with  a  dehy- 
drating agent  (e.g.,  concentrated  sulphuric  acid),  irritating  fumes  of  acrolein 
(acrylic  aldehyde),  C3H3OH,  are  evolved,   smelling  of  burning  fat.     By 
far  the  largest  application  of  glycerine  is  for  the  manufacture  of  nitro- 
glycerine, but  it  is  also  employed  extensively  in  the  manufacture  of  toilet 
soaps,  for  filling  gas-meters  and  tubes  in  situations  liable  to  be  exposed  to 
great  cold,  and  in  pharmacy  and  medicine.     It  is  also  used  for  the  preser- 
vation of  food  products,  and  for  the  treatment  (scheelizing)  of  wine,  vine- 
gar, and  beer. 

Nitro-glycerine  is  a  heavy,  oily  liquid  of  1.600  specific  gravity  at  15°  C. 
The  commercial  preparation  is  usually  yellowish  to  brownish,  although  the 
pure  oil  is  colorless.  It  has  no  marked  odor,  but  is  sensibly  volatile  at 
ordinary  temperatures,  and  the  vapor  causes  a  violent  headache  in  those 


PEODUCTS.  77 

unaccustomed  to  it ;  but  people  constantly  employed  in  mixing  and  handling 
dynamite  do  not  suffer  from  the  effects.  Nitro-glycerme  has  recently  been 
employed  in  medicine,  especially  for  the  treatment  of  angina  pectoris. 
Nitro-glycerine  is  not  readily  inflammable,  and  when  ignited  commonly 
burns  with  a  greenish  flame,  without  explosion.  The  most  characteristic 
property  of  nitro-glycerine,  and  that  which  gives  it  by  far  its  most  important 
application,  is  that  of  exploding  with  extreme  violence  when  smartly  struck 
or  compressed  or  when  dropped  on  an  iron  plate  heated  to  257°  C.  The 
presence  of  free  acid  in  nitro-glycerine,  however,  makes  it  liable  to  sponta- 
neous decomposition  and  explosion. 

Nitro-glycerine  is  easily  saponified  by  alcoholic  potash,  and  is  reduced 
by  various  deoxidizing  agents. 

Nitro-glycerine  in  undiluted  state  is  only  exceptionally  used  now  for 
explosive  purposes,  as  in  "  torpedoing"  oil-wells.  For  blasting  purposes  it 
is  mechanically  mixed  or  absorbed  in  some  finely  divided  solid  material. 

Thus,  Dynamite  No.  1  contains  seventy-five  per  cent,  of  nitro-glycerine 
mixed  with  twenty-five  per  cent,  of  infusorial  earth  or  kieselguhr.  This 
mixture  is  then  packed  in  cartridges  of  paraffined  paper,  constituting  the 
"  stick"  of  dynamite. 

Mica  powder  consists  of  fine  mica  scales  in  which  about  fifty  per  cent, 
of  nitro-glycerine  is  absorbed. 

Next  in  order  come  explosives  in  which  with  the  nitro-glycerine  is 
combined  an  active  base,  either  a  nitrate  or  a  mixture  of  nitrate  and  com- 
bustible substance,  like  charcoal  or  sulphur.  The  best  known  are : 

Dynamite  No.  2  contains  forty  per  cent,  of  nitro-glycerine,  sodium  nitrate 
thirty-eight,  sulphur  six,  resin  eight,  and  kieselguhr  eight. 

Dynamite  No.  3  contains  nitro-glycerine  fifteen,  and  eighty-five  of  a 
mixture  of  sodium  nitrate,  coal,  and  sodium  carbonate. 

Vulcan  powder  contains  nitro-glycerine  thirty,  sodium  nitrate  fifty-two 
and  five-tenths,  and  sulphur  and  charcoal  seventeen  and  five-tenths. 

Atlas  powder  A  and  B  contains  respectively  seventy-five  and  fifty  of 
nitro-glycerine,  with  sodium  nitrate,  wood  fibre,  and  magnesium  carbonate. 

Hercules  powder  is  similar  to  Atlas  powder  B,  but  contains  only  forty 
per  cent,  of  nitro-glycerine  and  forty-five  of  sodium  nitrate. 

Vigorite  contains,  with  thirty  of  nitro-glycerine,  potassium  chlorate 
forty-nine,  potassium  nitrate  seven,  wood  pulp  nine,  magnesium  carbonate 
and  moisture  five. 

Fordte  contains  nitro-glycerine  seventy-five,  potassium  nitrate  eighteen, 
and  gelatinized  cotton  seven.  This  latter  ingredient  is  made  by  treating 
finely  pulped  cotton  with  steam  under  pressure  until  converted  into  a  jelly, 
which  is  then  mixed  with  the  nitro-glycerine  and  the  finely  powdered  nitrate 
added.  The  resulting  product  is  a  plastic  mass  resembling  rubber,  impervious 
to  water,  and  relatively  safe  to  handle. 

Still  another  and  more  recently  developed  class  of  explosives  are  those 
in  which  nitro-cellulose  or  gun-cotton  is  combined  with  nitro-glycerine. 
The  most  important  are : 

Blasting  gelatine  or  gelatine  dynamite,  which  is  a  mixture  of  about 
eighty  parts  of  nitro-glycerine  with  twenty  of  mtro-cellulose.  Any  un- 
nitrated  cotton  or  trinitro-cellulose  interferes  with  the  solution  of  the  nitro- 
glycerine. The  addition  of  four  per  cent,  of  camphor  renders  the  mixture 
incapable  of  exploding  when  struck  by  a  rifle  bullet,  but  it  can  be  detonated 
by  a  strong  dynamite  cap. 


78  INDUSTRY   OF  THE   FATS   AND   FATTY    OILS. 

Cordite,  which  has  been  adopted  by  the  English  government  as  a  standard 
"smokeless  powder,"  contains  nitro-glycerine  fifty- eight,  gun-cotton  thirty- 
seven,  and  vaseline  five.  The  uitro-glycerine  and  gun-cotton  are  first  mixed, 
19.2  parts  of  acetone  added,  and  the  pasty  mass  kneaded  for  several  hours. 
The  vaseline  is  then  added  and  the  mixture  again  kneaded.  The  paste  is 
then  forced  through  fine  openings  to  form  threads,  which  are  dried  at  about 
40°  C.  until  the  acetone  evaporates.  The  threads  are  then  cut  into  short 
lengths  for  use.  They  resemble  a  brown  twine. 

There  are  analogous  explosives  known  as  "  smokeless  powders"  in  which 
no  nitro-glycerine  at  all  enters,  but  which  are  merely  cellulose  nitrates  or 
gun-cotton  gelatinized  and  dried,  as  just  described. 

Picrates  and  picric  acid  are  sometimes  used ;  but,  while  powerful  explo- 
sives, they  are  considered  too  unstable.  Melinite  and  Lyddite  are  of  this 


IV.  Analytical  Tests  and  Methods. 

1.  FOR  OILS  AND  FATS. — The  total  amount  of  oil  in  any  particular 
oil-seed  or  other  material  is  always  an  important  matter  to  determine. 
This  is  best  effected  by  treating  the  finely  divided  and  previously  dried 
substance  with  solvents  under  such  conditions  as  to  insure  complete  ex- 
traction. A  form  of  apparatus  in  which  this  can  be  effected  with  the 
minimum  amount  of  the  solvent  is  what  is  called  an  oleometer.  One  of  the 
best  of  these  is  the  Soxhlet  extractor,  shown  in  Fig.  31,  where  A  represents 
the  extractor,  B  the  distillation  flask,  C  the  condenser,  and  D  the  siphon- 
tube  which  empties  the  extractor.  A  is  filled  to  three-fourths  its  capacity 
with  the  powdered  oil  seed,  and  the  bulb  E  is  half  filled  with  petroleum- 
ether,  carbon  disulphide,  or  proper  solvent.  The  apparatus  is  then  con- 
nected, as  shown  in  the  cut.  As  the  Soxhlet  apparatus  is  rather  fragile 
and  liable  to  break  in  handling,  it  may  be  replaced  by  simpler  forms  of 
extractors.  Such  an  one  is  the  Thorn  extractor,  shown  in  Fig.  32,  the 
parts  of  which  are  easily  understood  from  the  illustration. 

To  recover  the  oil  from  its  solution  in  the  ether  or  other  liquid  employed, 
the  solvent  should  be  distilled  off  at  a  steam  heat,  and  the  last  traces  of  it 
removed  by  placing  the  flask  on  its  side  and  heating  it  in  the  water-oven 
until  constant  in  weight. 

The  physical  constants  which  are  relied  upon  as  characteristic  in  the  case 
of  oils  and  fats  are  specific  gravity,  and  in  the  case  of  solid  fats,  fusing 
points.  Boiling-points  are  not  relied  upon,  because  of  the  partial  decom- 
position which  fixed  oils  usually  undergo  when  heated  to  high  temperatures. 

Specific  gravity  in  the  case  of  the  liquid  oils  may  be  determined  with 
the  aid  of  the  specific  gravity  bottle,  the  Sprengel  tube,  or  the  Westphal 
hydrostatic  balance.  The  first  of  these  is  so  well  known  from  elementary 
works  on  chemistry  as  to  need  no  description  here.  The  Sprengel  tube  is  a 
U-shaped  tube,  of  which  the  two  ends  terminate  in  capillary  tubes  bent  at 
right  angles  to  the  sides.  The  tube  is  completely  filled  with  oil  by  im- 
mersing the  open  end  of  one  tube  in  the  liquid  and  gently  sucking  the  air 
out  from  the  other  orifice.  The  U-tube  is  then  placed  in  the  mouth  of 
a  conical  flask,  containing  boiling  water  (if  the  determination  is  to  be  made 
at  100°  C.)  or  water  at  any  other  fixed  lower  temperature.  The  excess  of  oil 
that  escapes  at  the  orifices  of  the  tube  is  wiped  off  with  soft  paper,  and  when 
the  expansion  ceases  the  tube  is  removed,  wiped  dry,  allowed  to  cool,  and 
weighed.  The  calculation  can  then  be  made,  knowing  the  weight  of  the 


ANALYTICAL  TESTS   AND  METHODS. 


79 


tube  empty  and  filled  with  water  at  the  same  temperature,  or  at  15°  C.  The 
Westphal  balance  is  shown  in  Fig.  33.  The  thermometer  or  other  plummet 
used  displaces  a  definite  volume  of  the  oil,  so  that  the  loss  in  weight  is  the 
weight  of  this  bulk  of  the  oil  under  examination. 

The  melting-point  of  solid  fats  may  be  gotten  with  considerable  accuracy 
by  the  melting-point  method  in  general  use  in  chemical  laboratories.     A 


FIG.  32. 


capillary  tube  is  filled  with  the 
fat  while  it  is  in  the  melted  state, 
and  then,  after  allowing  it  to  cool 
and  solidify,  attach  the  tube  to 
the  stem  of  a  delicate  thermometer 
and  immerse  the  thermometer  in 
a  beaker  of  water,  which  is  then 
gradually  heated  until  the  melting- 
point  of  the  fat  is  reached,  and  it  liquefies  in  the  capillary  tube.  The  tem- 
perature at  which  this  takes  place  is  at  once  read  off  on  the  attached  ther- 
mometer. To  insure  accuracy  it  is  desirable  to  immerse  the  beaker  of 
water  in  an  outer  vessel  also  filled  with  water,  to  which  the  heat  is  applied. 
Of  great  importance  with  some  of  the  fatty  oils,  such  as  sperm,  rape,  and 
lard  oils,  is  the  question  of  viscosity,  and  in  quite  a  number  the  question  of 


80 


INDUSTEY  OF  THE   FATS  AND   FATTY  OILS. 


cold  test.     The  methods  of  determining  these  have  been  given  in  detail 
under  mineral  oils.     (See  p.  39.) 

In  some  special  cases  the  use  of  the  oleo-refractometer,  an  instrument 
for  noting  the  difference  in  refractive  indices  of  oils,  has  proven  valuable. 
Thus,  true  butter  fat  can  be  distinguished  by  this  means  from  butterine  or 
oleomargarine. 

FIG.  33. 


A  number  of  chemical  reactions  have  been  taken  at  one  time  or  another 
for  the  purpose  of  distinguishing  between  the  different  animal  and  vegetable 
oils  and  fats.  Many  are  unreliable  and  the  results  contradictory,  because 
dependent  upon  special  conditions,  so  that  no  great  value  attaches  to  them. 
This  statement  may  fairly  be  said  to  apply  to  most  of  the  color-reactions 
which  are  gotten  by  the  action  of  sulphuric  and  nitric  acids  upon  the  dif- 
ferent oils  and  to  the  differences  ill  elevation  of  temperature  caused  by  the 
addition  of  concentrated  sulphuric  acid  to  the  fatty  oils. 

Of  much  greater  value,  as  affording  general  reactions  for  the  distinguish- 
ing of  the  different  oils  and  fats,  are  two  processes  of  treatment  now  very 
generally  adopted  by  chemists  in  the  analysis  of  fats  and  fatty  oils, — viz., 
the  saponification  value  and  the  bromine  or  iodine  absorption  value. 

The  saponification  value  (known  also  as  Kottstorfer  value)  indicates  the 
number  of  milligrammes  of  potassium  hydrate  required  for  the  complete 
saponification  of  one  gramme  of  the  fat  or  wax.  The  determination  is 
carried  out  as  follows.  About  1.5  to  2.5  grammes  of  the  fat  are  treated  with 


ANALYTICAL  TESTS  AND  METHODS. 


81 


twenty-five  cubic  centimetres  of  one-half  normal  alcoholic  potash ;  when 
saponification  has  taken  place,  one  cubic  centimetre  of  an  alcoholic  solution 
of  phenol-phthalein  is  added  and  the  liquid  titrated  with  one-half  normal 
hydrochloric  acid.  A  blank  experiment  is  then  made  by  titrating  twenty^ 
five  cubic  centimetres  of  the  alcoholic  potash  alone,  and  the  difference  in  the 
volumes  of  the  acid  used  gives  the  volume  of  the  potash  solution  neutralized 
by  the  fat,  which  is  then  calculated  to  milligrammes  of  potash  for  one  gramme 
of  fat  used.  The  following  are  a  few  examples  : 


OIL  OR  FAT. 

Milligrammes  of 
KOH  per  one  gramme 
of  fat. 

Average 
saturation- 
equivalent. 

Tallow  .                    

193.2  to  198.0 

286.9 

Lard.    .                

192.0  to  196.5 

288.8 

246.2  to  268.4 

218.4 

Palm-nut  oil        

220.0  to  247.6 

240.8 

Olive  oil        

191.0  (average) 

293.7 

Cotton-seed  oil                ....       .    . 

193.8    average) 

289.4 

Kape  oil            

173.3    average) 

323  7 

191.3    average) 

293.2 

Butter  fat         

221.5  to  232.4 

247.0 

193.5  to  196.5 

287.7 

Sperm  oil  .        

123.4  to  147.4 

380  to  454 

Spermaceti    ....        .        .        ... 

128.9  (average) 

435.2 

Beeswax   

94.5  (average) 

593.6 

The  numbers  in  the  last  column  designated  as  "  saturation  equivalents" 
represent  the  number  of  grammes  of  the  oil  or  fat  in  question  that  would  be 
decomposed  by  one  equivalent  of  potassium  hydrate  in  grammes,  and  is  ob- 
tained by  dividing  the  percentages  of  potassium  hydrate  required  into 
5610,  which  is  the  molecular  weight  of  KOH  multiplied  by  100.  These 
saturation-  or  saponification-equivalents  are  quite  characteristic  for  pure 
oils  or  fats,  and  allow  of  the  recognition  of  adulteration  in  many  cases. 

The  bromine  and  iodine  absorption  methods  depend  upon  the  percentage 
of  bromine  or  iodine  taken  up  by  the  oil  under  conditions  intended  to  insure 
the  formation  of  addition-compounds  only.  The  fatty  acids  of  the  acetic  or 
stearic  series  are  saturated  bodies,  which  do  not  form  addition-compounds 
with  bromine  or  iodine  while  the  acids  of  the  acrylic  or  oleic  series  combine 
with  two  atoms  of  a  halogen,  and,  those  of  the  propiolic  or  linoleic  series, 
with  four  atoms  of  a  halogen.  The  glycerides  of  the  acids  of  these  three 
series  behave  similarly  to  the  free  acids,  so  that  the  determination  of  the 
percentage  of  bromine  or  iodine  assimilated  gives  a  measure  of  the  proportion 
of  olein  as  against  palmitin  and  stearin  in  a  fat,  and  of  the  linolein  of  a  drying 
oil  as  compared  with  the  olein  of  a  non-drying  oil. 

The  bromine  absorptions  of  various  fixed  oils  have  been  determined  by 
Mills  and  others  (Journ.  Soc.  Chem.  Ind.,  ii.  p.  435 ;  iii.  p.  366),  the  method 
of  operating  ultimately  adopted  being  shortly  as  follows  :  About  .1  gramme 
of  the  oil,  previously  deprived  of  all  trace  of  moisture  by  heating  or  filtra- 
tion through  paper,  is  placed  in  a  stoppered  bottle  of  about  one  hundred 
cubic  centimetres  capacity,  and  dissolved  in  fifty  cubic  centimetres  of  carbon 
tetrachloride  (carbon  disulphide  was  first  used),  previously  dried  by  calcium 
chloride.  An  approximately  decinormal  solution  (eight  grammes  per  litre)  of 
bromine  in  dry  carbon  tetrachloride  having  an  exactly  known  strength  is 


82  INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 

then  added  gradually  to  the  solution  of  oil  until  there  is,  at  the  end  of  fif- 
teen minutes,  a  permanent  coloration.  This  is  compared  with  a  coloration 
similarly  produced  in  a  blank  experiment,  and  thus  a  measure  of  the  bro- 
mine-absorption is  obtained.  If  great  accuracy  be  desired,  an  excess  of 
bromine  may  be  used,  aqueous  solution  of  potassium  iodide  and  starch  added, 
and  the  solution  titrated  back  with  a  standard  solution  of  sodium  thio- 
sulphate. 

A.  H.  Allen  uses  a  modification  of  this  process,  which  he  terms  the 
"  moist  bromine  process,"  in  which  aqueous  solutions  are  used. 

The  determination  of  the  bromine  value  has  been  wholly  superseded  by 
HiibPs  *  method  of  ascertaining  the  iodine  absorption  value,  which  yields 
far  more  constant  and  reliable  results.  The  bromine  results,  however,  can 
be  calculated  if  desired  into  iodine  values  by  multiplication  with  l-ffi  = 
1.5875.  HiibPs  procedure  is  as  follows  : 

He  employs  an  alcoholic  solution  of  mixed  iodine  and  mercuric  chloride : 
twenty-five  grammes  of  iodine  are  dissolved  in  one-half  litre  of  alcohol, 
ninety-five  per  cent.,  free  from  fusel  oil.  and  thirty  grammes  of  mercuric 
chloride  in  another  one-half  litre  of  the  same.  The  two  solutions  are  then 
mixed  after  filtration,  if  necessary,  and  used  after  twelve  hours'  standing ; 
it  must  also  be  standardized  immediately  before  or  after  use.  About  .2  to 
.4  gramme  of  oils  or  .8  to  1  gramme  of  solid  fats  is  weighed  off  and  dis- 
solved in  ten  cubic  centimetres  of  chloroform  ;  twenty  cubic  centimetres  of 
iodine  solution  are  added,  and  successive  additions  of  five  or  ten  cubic  centi- 
metres are  made  until,  after  two  hours,  the  solution  has  a  dark  brown  tint. 
It  is  best  to  leave  it  for  from  four  to  six  hours  protected  from  the  light 
before  the  next  step.  From  ten  to  fifteen  cubic  centimetres  of  a  ten  per 
cent,  aqueous  solution  of  potassium  iodide  are  then  added  and  one  hundred 
and  fifty  cubic  centimetres  of  water.  The  free  iodine  is  then  titrated  with 
a  solution  of  sodium  thiosulphate  containing  twenty-four  grammes  per  litre. 
The  amount  of  iodine  absorbed  is  calculated  into  units  per  cent,  of  the  fat, 
and  may  conveniently  be  termed  the  iodine  degree.  This  number  appears 
to  be  tolerably  constant  for  each  oil,  or  class  of  oils,  and  is  highest  with 
the  vegetable  drying  oils,  as  will  be  seen  by  this  short  list  taken  from 
HiibPs  table :  linseed  oil,  158 ;  hemp-seed  oil,  143 ;  cotton-seed  oil,  106 ; 
olive  oil,  82.8;  lard,  59;  palm  oil,  51.5;  tallow,  40;  cocoa-nut  oil,  8.9. 
The  values  thus  obtained  are  quite  constant,  provided  an  excess  of  iodine 
of  not  less  than  thirty  per  cent,  be  employed  and  the  operations  be  carried 
out  under  exactly  the  same  conditions. 

HiibPs  method  of  iodine  absorption  has  been  found  very  useful  in  dis- 
tinguishing the  presence  of  cotton-seed  oil  in  both  lard  and  tallow.  Thus, 
pure  cotton-seed  oil  has  an  iodine  absorption  per  cent,  of  109.1,  while  pure 
tallow  has  only  40.8,  and  tallow  with  five  per  cent,  of  cotton-seed  oil,  44 ; 
tallow  with  ten  per  cent,  cotton-seed  oil,  47.1 ;  with  fifteen  per  cent.,  49.7 ; 
with  twenty  per  cent.,  52.9 ;  with  twenty-five  per  cent.,  56.1 ;  with  thirty 
per  cent.,  59.2  ;  and  with  forty  per  cent.,  66.2.|  In  the  analysis  of  lard,  the 
case  is  somewhat  complicated  by  the  frequent  admixture  of  beef  stearine,  as 
well  as  cotton-seed  oil.  Pure  lard  appears  to  have  an  iodine  absorption 
per  cent,  of  from  fifty-seven  to  sixty-three,  while  beef  stearine  has  only 
from  twenty-three  to  twenty-eight  per  cent.J 

*  Journ.  Soc.  Chem.  Ind.,  iii.  p.  641. 
f  K.  Williams,  Ibid.,  1888,  p.  187. 
j  J.  Pattinson,  Ibid.,  1889,  p.  31. 


ANALYTICAL  TESTS  AND  METHODS.  83 

For  qualitative  detection  only,  cotton-seed  oil  can  also  be  identified  in 
lard  by  Becchi's  test,  with  an  alcoholic  solution  of  silver  nitrate,  which  gives 
a  maroon  color  in  the  presence  of  the  cotton-seed  oil. 

Bizio  (Atti  del  R.  Institute  Veneto  di  Seienze,  iii.  6)  states,  however,  that 
this  coloration  will  be  produced  by  any  seed  oil,  olive  oil  among  others. 

The  adulteration  of  the  fatty  oils  very  frequently  calls  for  careful 
chemical  investigation.  The  presence  of  soap,  free  fatty  acids,  etc.,  in  them 
is  of  minor  importance ;  the  first,  readily  removable  by  washing  with  water 
after  dissolving  the  oil-sample  in  carbon  disulphide,  and  the  second  hardly 
to  be  called  an  adulteration,  as  free  fat  acids  are  normally  present  in  many 
vegetable  oils.  The  question  as  to  whether  they  are  present  may  be  settled 
by  Jacobsen's  method  of  adding  a  little  rosaniline  to  the  oil.  If  free  fatty 
acids  are  present,  the  oil  turns  red  in  color  in  consequence  of  the  formation 
of  rosaniline  oleate.  More  important  is  the  adulteration  with  resin  and  with 
hydrocarbon  oils.  In  the  absence  of  free  fatty  acids,  resin  may  be  isolated 
from  fixed  oils  by  agitating  the  sample  with  moderately-strong  alcohol,  sepa- 
rating the  spirituous  solution  and  evaporating  it  to  dryness.  The  sepa- 
ration of  the  resin  acids  from  free  fatty  acids  is  best  effected  by  a  method 
proposed  by  T.  S.  Gladding  (Amer.  Chem.  Journ.,  iii.,  No.  6),  which  is 
based  upon  the  ready  solubility  of  silver  resinate  in  ether,  and  the  almost 
complete  insolubility  of  silver  oleate,  etc.,  in  the  same  menstruum,  even  in  the 
presence  of  a  small  quantity  of  alcohol.  For  details,  the  reader  is  referred 
to  the  original  article.  Hydrocarbon  oils  may  generally  be  determined  by 
saponifying  the  sample  with  alcoholic  potash  (five  grammes  oil,  two  grammes 
caustic  potash,  and  twenty-five  cubic  centimetres  ninety  per  cent,  alcohol). 
The  soap  so  obtained  is  mixed  with  clean  sand,  the  alcohol  evaporated  over 
the  water-bath  at  a  temperature  of  not  over  50°  C.,  and  the  residue  extracted 
with  ether  or  petroleum  spirit.  From  this  solution,  on  evaporation  of  the 
solvent,  will  be  gotten  any  hydrocarbons  present. 

An  outline  method  of  analyzing  fatty  oils  containing  foreign  mixtures, 
due  to  Allen,*  is  given  on  the  following  page. 

The  analysis  of  soaps  is  a  most  important  matter,  as  with  the  varying 
composition  of  soaps,  shown  on  page  72,  a  control  is  absolutely  necessary 
for  those  using  or  purchasing  in  quantity.  One  of  the  most  satisfactory 
schemes  for  a  complete  soap  analysis  is  that  of  A.  R.  Leeds,  which  is  given 
on  page  85.  A  similar  one,  agreeing  with  that  of  Leeds  in  general  out- 
lines, is  given  by  Allen  f  in  his  excellent  work  on  "  Commercial  Organic 
Analysis."  In  the  water  determination,  great  care  must  be  taken  to  heat  gradu- 
ally at  not  too  high  a  temperature  at  first  (40°  to  50°  C.),  and  then  slowly 
to  increase  to  100°,  and  continue  until  no  further  loss  of  weight  is  observed. 

The  separation  of  the  mixed  fatty  acids  is  usually  only  effected  in  the 
mechanical  Avay  described  in  connection  with  stearic  acid.  (See  p.  67.)  An 
exact  chemical  separation  of  these  higher  fatty  acids  is  hardly  possible. 
The  most  satisfactory  method  known  is  that  of  Heintz  (Journ.  fur  Prae. 
Chem.,  Ixv.  i.),  based  on  the  fractional  precipitation  of  the  alcoholic  solution 
of  the  acids  with  magnesium  acetate.  This  salt  precipitates  acids  of  the 
stearic  series  more  easily  than  it  does  oleic  acid  and  its  homologues,  and  of 
the  different  homologues  of  the  stearic  series  those  of  the  highest  molecular 
weights  are  thrown  down  first. 

*  Allen,  Commercial  Organic  Analysis,  2d  ed.,  ii.  p.  87. 
f  Ibid.,  p.  251. 


84 


INDUSTRY   OF  THE  FATS  AND   FATTY  OILS. 


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ANALYTICAL  TESTS  AND   METHODS. 


85 


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acid,  and  calculate  as  NaaCOs. 


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weigh  as  silver  chloride.    Calculate  as  NaCl. 


Sodium    Sulphate.  — Weigh   as  barium   sulphate. 
Calculate  as  NazSC^. 


Sodium  Silicate.— Decompose  with  HC1  and  deter- 
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86  INDUSTRY  OF  THE  FATS  AND   FATTY  OILS. 

Commercial  glycerine  is  seldom  free  from  contamination,  and  a  variety 
of  impurities  are  liable  to  be  present.  The  impurities  of  raw  glycerine  are 
much  greater  in  number  and  amount  than  those  present  in  the  distilled 
product,  and  of  the  former,  glycerine  from  soap  lyes  is  much  more  impure 
than  the  product  resulting  from  the  autoclave  process.  Thus  the  mineral 
matter  remaining  as  ash  in  the  case  of  a  distilled  glycerine  never  amounts 
to  more  than  .2  per  cent.,  while  in  raw  glycerine  from  soap  lyes  the  ash 
usually  ranges  from  seven  to  fourteen  per  cent.,  and  in  that  from  the  auto- 
clave process  considerably  less.  The  ash  will  contain  common  salt,  and 
with  it  may  be  the  chlorides  and  sulphates  of  lead,  iron,  zinc,  magnesium, 
and  calcium.  In  glycerine  from  soap  lyes,  sulphates  particularly  are 
present.  They  may  be  accompanied  by  thiosulphates,  sulphites,  and  sul- 
phides resulting  from  the  sulphuric  acid  saponification  of  fats.  Such 
glycerines  are  purified  only  with  great  difficulty. 

Precipitation  with  basic  acetate  of  lead  often  serves  to  distinguish  be- 
tween a  distilled  and  an  undistilled  glycerine.  This  treatment  removes 
rosin,  while  rosin  oil  and  free  fatty  acids  are  removed  by  shaking  up  the 
sample  with  chloroform.  The  direct  determination  of  the  amount  of  true 
glycerine  in  commercial  samples  can  be  effected  with  moderate  accuracy  by 
the  method  of  oxidation  with  potassium  permanganate  in  alkaline  solution, 
whereby  the  glycerine  is  oxidized  to  oxalic  acid,  which  is  then  determined  as 
calcium  salt.  For  details,  the  reader  is  referred  to  Allen's  "  Commercial 
Organic  Analysis,"  3d  ed.,  vol.  ii.,  Part  i.,  p.  314. 

More  accurate  is  said  to  be  the  "  acetin"  method  of  Benedikt  & 
Cantor,  which  depends  upon  the  quantitative  formation  of  glyceryl  triace- 
tate when  glycerine  is  heated  with  acetic  anhydride.  It  is  carried  out  as 
follows :  1  to  1.5  grammes  of  the  crude  glycerine  is  heated  with  seven  or 
eight  grammes  acetic  anhydride  and  about  three  grammes  anhydrous  sodium 
acetate  for  one  to  one  and  a  half  hours  with  inverted  condenser ;  it  is 
allowed  to  cool,  fifty  cubic  centimetres  of  water  are  added,  and  the  heating 
with  inverted  condenser  continued  until  it  begins  to  boil.  When  the  oily 
deposit  at  the  bottom  of  the  flask  is  dissolved  the  liquid  is  filtered  from  im- 
purities, allowed  to  cool,  phenol-phthalein  added,  and  dilute  caustic  soda 
(about  twenty  grammes  per  litre)  run  in  until  neutrality  is  obtained.  Care 
must  be  taken  not  to  exceed  that  point,  or  glyceryl  triacetate  is  easily 
saponified.  Twenty-five  cubic  centimetres  of  strong  caustic  soda  (about 
ten  per  cent,  strength)  are  now  added  from  a  pipette.  The  mixture  is  then 
heated  for  fifteen  minutes  and  the  excess  of  alkali  titrated  back  with  normal 
or  half-normal  hydrochloric  acid.  The  strength  of  the  alkali  used  is  then 
determined  by  measuring  twenty-five  cubic  centimetres  with  the  same 
pipette  and  titrating  it  with  the  same  acid.  The  difference  in  the  two 
titrations  gives  the  amount  of  alkali  consumed  in  saponifying  the  glyceryl 
triacetate,  and  from  this  the  glycerine  can  be  calculated. 

Various  methods  have  been  proposed  for  the  analysis  of  nitro-glycerine, 
based  upon  its  decomposition  by  different  reagents.  One  of  the  simplest 
and  most  satisfactory  is  that  proposed  by  Lunge,  who  uses  for  this  purpose 
his  nitrometer.  (See  p.  300.)  An  accurately-weighed  quantity,  varying  from 
.12  to  .35  gramme,  according  to  the  proportion  of  nitro-glycerine  and  the 
capacity  of  the  apparatus,  is  introduced  into  the  cup  of  a  nitrometer  filled 
with  mercury.  About  two  cubic  centimetres  of  concentrated  sulphuric  acid 
is  then  added,  and  when  the  nitro-glycerine  is  dissolved  the  solution  is 
allowed  to  enter  the  nitrometer  through  the  tap.  The  cup  is  rinsed  with 


BIBLIOGRAPHY  AND   STATISTICS.  87 

successive  portions  of  two  cubic  centimetres  and  one  cubic  centimetre  of 
strong  sulphuric  acid,  which  are  allowed  to  enter  as  before,  and  the  contents 
of  the  nitrometer  are  then  thoroughly  agitated  in  the  usual  way,  and  the 
volume  of  nitric  oxide  evolved  read  off  after  standing  about  fifteen  minutes. 
The  volume  of  gas  in  cubic  centimetres  at  the  standard  pressure  and  tem- 
perature, multiplied  by  3.37,  gives  the  weight  of  nitro-glycerine  in  milli- 
grammes. Hempel  states  that  the  total  volume  of  five  cubic  centimetres 
of  sulphuric  acid  must  not  be  departed  from ;  with  less  than  that  volume 
the  reaction  proceeds  too  slowly,  and  with  more  the  results  are  too  low. 

In  the  analysis  of  dynamite,  the  nitro-glyv  3rine  may  be  conveniently 
determined  by  exhausting  the  dried  sample  with  anhydrous  ether,  prefer- 
ably in  a  Soxhlet  tube  (see  p.  79),  and  weighing  the  insoluble  residue. 
The  nitro-glycerine  is  estimated  from  the  loss,  and,  in  the  absence  of  other 
substances  soluble  in  ether,  such  as  camphor,  resin,  etc.,  this  is  the  most 
satisfactory  way.  A  complete  scheme  for  the  analysis  of  all  nitro-glycerine 
preparations  will  be  found  in  Allen,  3d  ed.,  vol.  ii.,  Part  i.,  p.  339. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1867. — Die  Chemie  der  Austrocknenden  Oele,  G.  J.  Mulder,  Berlin. 

1872. — The  Olive  and  its  Products,  and  the  Manufacture  of  the  Oil,  L.  A.  Bernays,  Bris- 
bane. 

1876. — The  Oil  Seeds  and  Oils  in  the  India  Museum,  M.  C.  Cooke,  London. 
1878. — Die  Industrie  der  Fette,  C.  Deite,  Braunschweig. 
1879. — Commercial  Products  of  the  Sea,  P.  L.  Simmonds,  London. 

Die  Nutzpflanzen  aller  Zonen,  L.  Wittmack,  Berlin. 
1880. — Corps  Gras,  A.  Kenard,  Kouen. 

Die  Fettwaaren  und  fetten  Oele,  C.  Lichtenberg,  "Weimar. 
1881. — Matieres  Premieres  Organiques,  G.  Pennetier,  Paris. 

Soap  and  Candles,  R.  S.  Christiani,  Philadelphia  and  London. 

Die  Fette  und  Oele,  F.  Thalmann,  Leipzig. 
1882. — Die  Trocknenden  Oelen,  L.  E.  Andes,  Braunschweig. 
1883. — Analysis  and  Adulteration  of  Foods,  James  Bell,  London. 

Das  Glycerin,  Koppe,  Wien. 

1885. — Soap  arid  Candles,  W.  L.  Carpenter,  London  and  New  York. 
1886.— Analyse  der  Fette  und  Wachsarten,  K.  Benedikt,  Berlin. 

Das  Wachs  und  seine  technische  Verwendung,  S.  Sedna,  Wien. 
1887. — The  Art  of  Soap-making,  A.  Watt,  London. 

Guide  pratique  du  Fabricant  de  Savons,  etc.,  Calmels  et  Saulnier,  Paris. 

Handbuch  der  Seifenfabrikation,  C.  Deite,  Berlin. 

Theorie  et  pratique  de  la  Fabrication  des  Bougies  et  des  Savons,  Larue  et  Droux, 
Paris. 

Traite  pratique  de  Savonnerie,  E.  Morritz,  Paris. 
1888. — Soap  and  Candles,  J.  Cameron,  London. 

Manufacture  of  Soap  and  Candles,  W.  T.  Brannt,  Philadelphia  and  London. 

Handbuch  der  praktischen  Kerzenfabrikation,  Al.  Englehardt,  Wien. 

Seifenfabrikation,  2  Bds.,  Al.  Englehardt,  Wien. 

Report  of  House  Committee  on  Compound  Lard,  Washington. 
1889.— Lard  and  Lard  Adulteration,  H.  W.  Wiley  (Bulletin  No.  13),  Washington,  D.  C. 

Die  fetten  Oele  des  Pflanzen-  und  Thierreiches,  Bornemann,  Weimar. 

Der  praktische  Seifenseider,  H.  Fischer,  Weimar. 

Die  Fetten  Oele,  G.  Bornemann,  Weimar. 

Tropical  Agriculture,  P.  L.  Simmonds,  3d  ed.,  London  and  New  York. 
1890. — Die  Unterschungen  der  Fette,  Oele,  Wachsarten,  etc.,  C.  Schaedler,  Leipzig. 

A  Dictionary  of  Explosives,  J.  P.  Cundill,  London. 

A  Hand-Book  of  Modern  Explosives,  M.  Eissler,  New  York. 

Les  Corps  Gras,  A.  M.  Villon,  Paris. 
1891. — Les  Matieres  Grasses,  G.  Beauvisage,  Paris. 
1802. — Chemie  analytique  du  Matieres  Grasses,  Ferd.  Jean,  Paris. 

Die  Technologic  der  Fette  und  Oele,  C.  Schaedler,  2te  Auf.,  Leipzig. 


88  INDUSTRY   OF  THE  FATS   AND   FATTY   OILS. 

1893. — Les  Explosives,  Roman,  Paris. 

Soap  Manufacture,  W.  L.  Gadd,  London. 

Vegetabilische  und  Mineral-Maschinenole,  L.  E.  Andes,  Wien. 
1894. — Die  Schmiermittel,  Jos.  Grossmann,  Wiesbaden. 

Oils,  Fats,  and  Waxes,  C.  R.  Alder  Wright,  London. 

Savons  et  Bougies,  J.  Lefevre,  Paris. 
1895. — Die  Industrie  der  Explosivestoffe,  O.  Guttmann,  Braunschweig. 

Die  Explosivestoife,  Fr.  Bockmann,  2te  Auf.,  Wien  and  Leipzig. 
1896.— Animal  and  Vegetable  Fats  and  Oils,  W.  T.  Brannt,  2d  ed.,  Philadelphia. 
1897. — Vegetable  Fats  and  Oils,  L.  E.  Andes,  translated  into  English,  London. 

Lubricating  Oils,  Fats,  and  Greases,  G.  H.  Hurst,  London. 

1898. — Chemical  Analysis  of  Oils,  Fats,  and  Waxes,  J.  Lewkowitsch,  2d  ed.,  London 
and  New  York. 

Animal  Fats  and  Oils,  L.  E.  Andes,  translated  by  C.  Salter,  London. 

Hand-Book  of  Oil  Analysis,  A.  H.  Gill,  Philadelphia. 

Lubricants,  Oils,  and  Greases,  I.  I.  Redwood,  New  York. 
1899.— Die  Seifenfabrikation,  F.  Wiltner,  Wien. 

Soaps :  A  Practical  Treatise,  G.  H.  Hurst,  London. 


STATISTICS. 

1.  OF  OILS,  FATS,  AND  WAXES. — Of  the  production  of  the  various 
vegetable  and  animal  oils,  fats,  and  waxes  the  figures  are  fragmentary. 
While  they  do  not  always  give  a  proper  view  of  these  industries,  they  will 
suffice  to  indicate  in  a  general  way  the  degree  of  their  development. 

Cocoa-nut  Oil. — The  annual  yield  of  nuts  in  Ceylon  may  be  taken  at 
1,100,000,000.  In  1898  the  exports  of  cocoa-nut  oil  from  this  island 
amounted  to  435,000  hundredweight,  and  in  1899  to  400,000  hundred- 
weight, besides  large  quantities  of  "  copra"  (the  dried  pulp  of  the  cocoa- 
nut)  and  cocoa-nuts.  Large  amounts  are  also  exported  from  the  Eastern 
Archipelago,  from  British  India,  and  from  the  Pacific  Islands.  The  nuts 
are  also  exported  from  the  West  Indies,  from  Central  America,  and  from 
Brazil. 

The  English  importations  of  cocoa-nut  oil  in  recent  years  have  been : 

1895 285, 01 6  cwt.,  valued  at  £321, 550 

1896 219,204    "  "       "     249,633 

1897 242,731    "  "       "     265,068 

1898 307,101    "  "       ".    344,108 

1899 458,297     "  "       "     545,642 

Palm  Oil. — The  exportation  of  palm  nuts  from  Southern  Africa,  accord- 
ing to  Dr.  von  Scherzer,  reaches  1,300,000  metric  centners  annually,  of 
which  the  greater  part  goes  to  France.  The  exportation  of  nuts  from 
British  India,  Siam,  Cochin-China,  China,  South-Sea  Islands,  and  Brazil 
together  amounts  to  600,000  metric  centners. 

The  English  importations  of  palm  oil  in  recent  years  have  been  : 

1895 1,262,933  cwt,  valued  at  £1,320,690 

1896 1,146,391  "     "   "  1,204,679 

1897 973,108  "     "   "  1,001,368 

1898 910,900  »     "   "    975,447 

1899 945,472  "    "   «  1,037,265 

Olive  Oil  is  produced  chiefly  in  Mediterranean  lands  and  in  the  East. 
The  area  under  olive  culture  in  Italy  is  now  2,258,000  acres.  The  oil 
production  of  1885  was  stated  to  be  3,338,825  hectolitres.  The  export  of 


BIBLIOGRAPHY  AND  STATISTICS.  89 

olive  oil  from  Italy  ranges  from  50,000,000  kilos,  to  92,000,000  annually, 
according  to  the  crop  of  olives  (Simmonds's  Tropical  Agriculture,  p.  394). 
Spain  has  some  2,500,000  acres  devoted  to  olive  culture,  and  the  average 
annual  production  of  oil  for  the  last  five  years  has  been  2,976,384  metric 
centners.  Of  this  the  home  consumption,  for  food,  lighting,  soap-making, 
etc.,  took  2,754,064  metric  centners,  leaving  222,320  metric  centners  for 
export.  France  had,  a  few  years  ago,  317,800  acres  of  olives  under  culti- 
vation, producing  7,318,352  bushels  of  fruit  and  392,618  hundredweight  of 
oil.  The  total  Greek  export  in  1875  was  12,244,615  okes  (of  2.83  pounds). 
The  Algerian  production  in  1877  was  55,239,000  kilos,  of  fruit,  yielding 
1,543,400  hectolitres  (of  twenty-two  gallons)  of  oil.  (Spon.)  The  ex- 
portation of  Turkey  and  the  Turkish  provinces  is  estimated  at  900,000 
metric  centners  annually.  (Heinzerling.) 

The  importations  of  olive  oil  into  France  is  estimated  at  20,000,000 
kilos,  annually,  and  the  exportation  at  5,000,000  kilos.  (Schaedler.) 

The  English  importations  of  olive  oil  for  recent  years  have  been  as 
follows : 

1895.       1896.      1897.       1898.      1899. 

Olive  oil  in  tuns  (252  wine  gals.)      14,834         18,853         15,440         18,044        15,930 
Valued  at £522,811    £612,876    £515,531    £608,122    £553,286 

The  United  States  importations  of  olive  salad  oil  have  been  as  follows : 

1895.       1896.        1897.      1898.       1899. 

Gallons 775,046          942,598          928,567       736,877          930,042 

Valued  at  ...  $952,405    $1,107,049    $1,134,077     $923,804    $1,090,250 

Corn  Oil. — Within  the  last  few  years  corn  oil  has  become  an  important 
article  of  export.  The  figures  are  as  follows : 

1898 2, 646, 500  gallons,  valued  at  $575, 646 

1899 2,360,623         "  "  565,293 

Rape  or  colza  oil  is  cultivated  in  Germany,  France,  Austria,  Hungary, 
Russia,  Roumania,  and  India.  The  area  in  Germany  planted  with  the  dif- 
ferent varieties  of  brassica  amounted  in  1882  to  445,000  acres,  the  crop 
of  rape  seed  to  1,882,000  metric  centners,  valued  at  50,500,000  marks. 
The  importations  of  rape  seed  into  Germany  were  in  1882,  681,000  metric 
centners,  and  in  1883,  1,154,290  metric  centners.  After  deducting  the  seed 
for  sowing,  some  2,500,000  metric  centners  were  available  for  oil  produc- 
tion, and  from  this  900,000  to  1,000,000  metric  centners  of  oil,  valued  at 
48,000,000  to  56,000,000  marks,  and  1,300,000  metric  centners  of  oil-cake, 
valued  at  17,000,000  marks,  were  obtained. 

England  imports  some  800,000  metric  centners  of  rape  seed  annually, 
and  produces  quite  an  amount.  Austria  presses  for  oil  about  550,000 
metric  centners  of  rape  seed  annually,  obtaining  200,000  to  225,000  metric 
centners  of  oil.  The  total  consumption  of  rape  and  colza  oil  in  Europe  is 
estimated  at  2,800,000  to  3,000,000  metric  centners  per  annum,  valued  at 
170,000,000  to  175,000,000  marks.  (Heinzerling.) 

The  exportation  of  rape  seed  from  Russia  in  1879  amounted  to  1,294,728 
bushels,  and  from  Roumanian  ports,  on  the  Danube,  in  1878,  to  938,376 
bushels.  The  shipments  from  India  in  recent  years  have  been  as  follows : 

1885.  1886.  1887. 

4,521,933  cwt.  3,721,840  cwt.  2,664,693  cwt. 


90  INDUSTKY   OF  THE   FATS  AND   FATTY   OILS. 

Sesame  Oil. — The  seeds  come  chiefly  from  the  East  Indies  and  the 
Levant,  and  the  oil  is  pressed  in  Marseilles  and  Trieste.  British  India 
exported  in  1885,  2,646,484  hundredweight;  in  1886,  1,759,343  hundred- 
weight; and  in  1887,  2,121, 11T  hundredweight.  France  imports  some- 
what more  than  1,000,000  metric  centners ;  England,  250,000  metric 
centners;  Italy,  150,000  metric  centners;  and  Germany,  140,000  metric 
centners  of  sesame  seeds. 

Ground-nut  Oil. — The  ground-nut  (pea-nut),  while  indigenous  to 
America,  is  now  cultivated,  for  the  oil  it  contains,  in  Africa,  India,  the 
West  Indies,  and  Brazil.  The  American  production,  located  chiefly  in  the 
States  of  North  Carolina,  Virginia,  and  Tennessee,  amounts  to  an  average 
of  3,500,000  bushels,  or  77,000,000  pounds.  The  production  of  1899 
exceeded  the  average,  amounting  to  4,500,000  bushels.  The  average  pro- 
duction of  "  Spanish  pea-nuts"  in  the  United  States  amounts  to  16,500,000 
pounds.  About  400,000,000  pounds  are  annually  exported  from  India  and 
Africa,  of  which  about  half  goes  to  Marseilles  to  be  expressed  for  oil.  The 
importations  at  Marseilles,  where  the  oil  is  chiefly  extracted,  have  been  for 
the  last  few  years  : 

Shelled.  Unshelled.  Total. 

1897 8,355  tons.  31,888  tons.  40,243  tons. 

1898 5,466     "  63,286     "  68,752     " 

1899. 9,579     "  61,241     "  70,820     " 

It  is  estimated  that  3,250,000  bushels  are  annually  eaten  in  the  United 
States. 

Cotton-seed  Oil. — In  the  United  States,  it  is  reckoned  that  for  each 
one  pound  of  ginned  cotton  there  are  two  pounds  of  seed.  As  the  cotton 
crop  of  1898  was  11,189,205  bales  of  470  pounds,  or  5,258,926,350  pounds, 
the  production  of  seed  must  have  been  about  10,517,852,700  pounds,  or 
some  4,695,470  tons.  About  one-third  of  this  is  required  for  sowing. 
The  balance,  3,130,313  tons  of  crude  seed,  when  hulled,  would  yield  about 
1,750,000  tons  of  hulled  seeds.  Each  ton  of  hulled  seeds  yields  45  gallons 
of  crude  cotton-seed  oil  and  800  pounds  of  cotton-seed  cake. 

Of  this  annual  production  of  crude  cotton-seed  oil,  perhaps  one-fourth 
goes  into  the  production  of  u  compound  lard,"  and  the  rest  is  partly  ex- 
ported as  cotton-seed  oil,  partly  used  in  admixture  with  drying  oils,  and 
partly  as  soap- stock. 

The  exportations  of  cotton-seed  oil  from  the  United  States  for  the  last 
few  years  have  been  as  follows : 

1895.        1896.        1897.         1898.         1899. 

Cotton-seed  oil  in  gallons  .  21,187,728    19,445,848    27,198,882      40,230,784      50,627,219 
Valued  at $6,813,313    $5,476,510    $6,897,361     $10,137,619    $12,077,519 

In  Europe,  England  is  the  chief  country  extracting  the  oil  from  the 
cotton  seed,  which  comes  chiefly  from  Egypt.  The  imports  of  seeds  into 
England  for  1886  were  255,701  tons;  for  1887,  276,570  tons;  for  1888, 
255,500  tons. 

Hemp-seed  oil  is  produced  chiefly  in  Russia.  The  exports  of  hemp 
seed  from  Riga  in  1878  were  629,520  bushels,  and  in  1879,  725,809  poods 
(of  thirty-six  pounds)  of  seed  and  573  poods  of  the  oil.  (Spon's  "  Encyclo- 
pedia.") 


BIBLIOGRAPHY  AND   STATISTICS.  91 

Linseed  Oil. — The  supplies  of  linseed  come  from  all  countries,  but  most 
largely  from  Kussia,  the  United  States,  and  India.  The  world's  crop  of 
linseed  in  recent  years  has  been  as  follows : 

1896.  1897.  1898. 

Bushels.  Bushels.  Bushels. 

Kussia 39,625,000  27,296,500  28,537,500 

United  States 17,402,000  11,000,000  18,500,000 

British  India 14,795,000  8,839,000  17,839,000 

Argentina 7,500,000  7,000,000  9,000,000 

Austria 743,000  724,000  802,000 

Koumania 674,000  676,000  461,000 

Belgium 394,000  350,000  400,000 

France 523,000  524,000  357,000 

Mexico 108,000  222,500  311,000 

Netherlands 312,000  275,000  308,000 

Manitoba 267,500  255,500  305,500 

Hungary 271,000  278,000  301,000 

Sweden 70,000  73,500  75,000 

82,684,500  57,514,000  77,197,000 

In  1895,  4,166,222  bushels  of  linseed,  valued  at  $4,554,484,  were  im- 
ported into  the  United  States.  This  dropped  off  to  less  than  one-fifth  the 
following  year,  and  has  since  almost  ceased.  In  1897,  4,713,747  bushels, 
valued  at  $3,850,835,  were  exported,  and  again  in  1899,  2,830,991  bushels, 
valued  at  $2,815,449. 

Oil-cake  and  Oil-cake  Meal. — The  exportations  of  vegetable  oil-cake 
from  the  United  States  have  been  during  recent  years  as  follows : 

1895.  1896.  1897.  1898.                   1899. 

Cotton-seed  cake  (Ibs.)  489,716,053  404,937,291  623,386,638  919,727,7011,079,993,479 

Valued  at $4,310,128  $3,740,232  $5,515,800  $8,040,710        $9,253,398 

Linseed  cake  (Ibs. ).    .243,936,442  393,429,432  433,106,448  436,206,321      487,177,390 

Valued  at $2,855,459  $4,209,415  $4,095,244  $4,540,824       $5,277,744 

Fish  Oils. — The  amounts  of  sperm,  whale,  and  fish  oils  of  all  kinds 
obtained  annually,  according  to  Mulhall,*  are :  sperm  and  whale  oil, 
1,485,000  hectolitres  (32,670,000  gallons);  fish  oils  of  other  kinds, 
1,170,000  hectolitres  (25,740,000  gallons),  and  oil  from  sea-birds,  58,500 
hectolitres  (1,287,000  gallons). 

The  English  importations  of  train  and  other  fish  oils  during  the  last 
few  years  were : 

1895.       1896.       1897.       1898.       1899. 

Amount  in  tuns  .    .       24,597          21,961  18,129          20,673          20,358 

Valued  at.    .    .    .£406,448     £366,279      £280,977     £350,348     £346,996 

The  exportations  of  whale  and  fish  oils  from  the  United  States  for  the 
last  five  years  have  been  : 

1895.        1896.        1897.        1898.        1899. 

Gallons  ....     769,179          844,125          853,340          669,227         1,026,125 
Valued  at  .    .  $198,767        $196,701        $176,285        $145,920         $227,312 

Cod-liver  Oil. — The  annual  production  of  Newfoundland  is  said  to 
amount  to  1,250,000  gallons,  valued  at  £200,000. 

The  Norwegian  cod-liver  oil  production  from  the  three  districts  of 

*  Mulhall,  Production  and  Consumption,  p.  142. 


92 


INDUSTRY   OF  THE   FATS  AND   FATTY   OILS. 


Lofoten,  Romsdal,  and  Lodde  is  thus  given  on  the  authority  of  F.  P. 
Moller  (Cod-liver  Oil  and  Chemistry,  London,  1895) : 


YEAR. 

Number  of  fish. 

Barrels  of  com- 
mon liver  oil. 

Barrels  of  steam- 
prepared  liver  oil. 

1890  

51,614  000 

58  535 

21  173 

1891  

40,880  000 

33  815 

22  331 

1892 

44  212  000 

47  OKI 

Ifi  39,1 

1893. 

47  738  000 

41  851 

IQ  7^7 

1894.    .       .               

52,484,000 

34  670 

21  294 

Spermaceti  and  Sperm  Oil. — The  production  of  spermaceti  in  the  Ameri- 
can whale-fisheries  was  1,300,959  gallons  in  1878,  and  1,285,454  gallons 
in  1879.  The  exports  of  sperm  oil  from  New  York  in  1878  were  912,603 
gallons,  and  in  1879,  1,089,137  gallons.  (Spon's  "Encyclopedia.")  The 
exportations  of  sperm  oil  have  much  diminished  in  more  recent  years. 
Thus,  the  exports  for  1889  and  1890  were  given  as  98,823  gallons  and 
162,565  gallons  respectively,  valued  at  $69,628  and  $124,601,  and  have 
since  ceased  almost  entirely. 

Lard  and,  Lard  Oil. — The  production  of  lard  in  the  United  States 
during  recent  years  is  thus  given  by  the  Cincinnati  Price  Current  : 


1884-85. 
Pounds. 


1885-86. 
Pounds. 


1886-87. 
Pounds. 


1887-88. 
Pounds. 


1888-89. 
Pounds. 


1889-90. 
Pounds. 


480,405,000     514,230,000     527,032,000     487,179,000     483,902,000     624,227,000 

Of  this  production  from  one-third  to  one-half  is  "  compound  lard,"  or 
lard  admixed  with  cotton-seed  oil  and  beef  stearine. 

The  exports  of  lard  from  the  United  States  during  recent  years  have 
been  as  follows : 

1895.         1896.         1897.         1898.        1899. 

Pounds  .    .    .  474,895,274     509,534,256     568,315,640     709,344,045     711,259,851 
Valued  at  .  $36,821,608    $33,589,851     $29,126,485    $39,710,672    $42,208,465 

Of  this  amount  approximately  one-third  goes  to  Great  Britain  and 
Ireland  and  one-third  to  Germany. 

The  exports  of  lard  oil  during  the  same  years  were : 


Gallons  .. 
Valued  at 


1895. 

553,421 

$304,093 


1896. 

833,935 

$426,401 


1?97. 

961,407 

$419,803 


1898. 

775,102 

$305,825 


1899. 

917,007 

$412,447 


Tallow.  —  The  production  of  tallow  for  all  European  countries  for  the 
year  1882,  according  to  Mulhall,*  amounted  to  355,700  tons,  for  the  United 
States  to  330,000  tons,  and  all  other  countries,  60,000  tons,  making  a  total 
of  745,700  tons.  The  exportations  of  Russian  tallow  have  greatly  dimin- 
ished in  recent  years  ;  they  were  40,300  tons  in  1860,  21,100  tons  in  1870, 
and  10,400  tons  in  1880.  The  exportations  from  the  United  States,  River 
Plate  in  South  America,  and  Australia,  on  the  other  hand,  have  increased, 
especially  the  first  and  the  last  of  these.  In  the  year  1883  the  exporta- 
tions of  tallow  were  as  follows  :  From  the  United  States,  45,000  tons  ;  from 
Australia,  28,000  tons  ;  from  Argentine  Republic,  10,500  tons,  and  from 
Uruguay,  12,000  tons.  (Heinzerling.) 


*  Mulhall,  Dictionary  of  Statistics,  p.  434. 


BIBLIOGRAPHY  AND  STATISTICS.  93 

The  expectations  from  the  United  States  in  recent  years  have  been : 

1895.         1896.         1897.         1898.         1899. 

Pounds   .    .    .  25,864,300       52,759,212       75,108,834       81,744,809       107,361,009 
Valued  at  .  $1,293,059      $2,323,764      $2,782,595      $3,141,653        $4,367,356 

The  English  importations  of  tallow  and  stearine  during  the  same  period 
have  been : 

1895.         1896.        1897.        1898.        1899. 

Hundredweight  .     2,175,822        2,049,749        1,950,975       2,021,921        2,061,137 
Valuedat.    .    .£2,575,071     £2,178,652     £1,870,289     £2,066,433     £2,380,931 

Chinese  or  Insect  Wax. — The  amount  annually  produced  is  valued  by 
Professor  Thistleton  Dyer,  of  Kew  Gardens,  England,  at  £600,000. 

Carnauba  Wax. — The  exportation  of  this  wax  from  Brazil  was  esti- 
mated in  1876  at  871,400  kilos.,  valued  at  £162,500. 

Japan  Wax. — The  exportations  from  Japan  were  in  1872,  1,230,588 
kilos.;  in  1873,  1,520,751  kilos.,  and  in  1874,  1,302,465  kilos.  The 
London  importations  in  1880  were  564,000  kilos.,  and  in  1881,  666,660 
kilos. 

Soaps. — Sir  Henry  Roscoe  stated,  in  1881,  in  his  inaugural  address 
before  the  Society  of  Chemical  Industry,  that  the  annual  production  of  soap 
in  Great  Britain  and  Ireland  was  about  250,000  tons.  In  a  report  on  the 
exhibits  at  the  Paris  Exposition  of  1878,  it  was  stated  that  the  French  soap- 
trade  had  been  for  some  time  stationary  at  about  220,000  tons  per  annum, 
but  was  then  declining. 

The  English  export  of  soaps  for  the  last  five  years  has  been  : 

1895.       1896.       1897.       1898.       1899. 

Hundredweight  .    .     728,398         719,651         738,564         805,665         930,827 
Valued  at     ...  £756,704      £744,848      £762,248      £831,207      £942,269 

The  United  States  imports  some  soap  (chiefly  toilet  and  fancy  grades) 
and  exports  a  still  larger  amount  (chiefly  plainer  grades).  Thus,  in  recent 
years  the  values  were  : 

1897.  1898.  1899. 

Imports.        $766,376  $498,512  $576,197 

Exports 1,136,880  1,390,603  1,457,610 

Glycerine. — The  total  output  of  crude  glycerine  in  the  world  is  said  to 
be  40,000  tons  per  annum,  of  which  14,000  tons  are  obtained  in  soap 
manufacture  and  26,000  tons  in  stearine  manufacture.  The  glycerine  from 
these  two  sources  is  produced  as  follows : 

From  soap-  From  stearic  acid 

making.  manufacture. 

England  ........      5500  tons.  1200  tons. 

France 3500    »  6000 

Germany 2000    «  3000 

United  States 3000    "  3000 

Holland  ...» .  2000 

Austria 2000 

Russia 2000 

Belgium 1800 

Italy 1800 

Spain 1500 

Other  countries 1700 


94  INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  KESINS. 


CHAPTER    III. 

INDUSTRY   OF   THE   ESSENTIAL   OILS   AND   RESINS. 

I.  Raw  Materials. 

1.  ESSENTIAL,  OILS. — The  essential  or  volatile  oils,  as  they  are  termed, 
are  found  extensively  distributed  throughout  the  vegetable  kingdom. 
They  occur  in  almost  all  parts  of  the  plants  except  the  cotyledons  of  the 
seeds,  in  which,  in  general,  the  fixed  or  fatty  oils  are  contained.  The 
essential  oils  impart  the  peculiar  and  characteristic  odors  to  the  plants ;  they 
furnish  us  our  perfumes,  spices,  and  aromatics,  and  many  of  them  possess 
valuable  medicinal  properties. 

The  essential  or  volatile  vegetable  oils  are  procured  in  several  ways : 
(1)  by  distillation ;  (2)  by  absorption  or  "  enfleurage" ;  (3)  by  means  of 
solvents  ;  (4)  by  expression ;  and  (5)  by  maceration. 

In  the  distillation  method  the  plants  are  put  into  the  still  along  with 
about  an  equal  weight  of  water,  either  with  or  without  previous  soaking, 
and  the  distillation  carried  on  rapidly.  If  necessary,  the  water  that  sepa- 
rates from  the  oil  in  the  receiver  is  returned  to  the  still  and  driven  over  a 
second  or  third  time.  The  separation  of  the  oil  and  water  is  eifected  in 
what  is  termed  a  "  Florentine  receiver,"  from  the  bottom  of  which  the 
water  can  be  siphoned  off  without  disturbing  the  oily  layer.  The  odors  of 
some  flowers,  such  as  jessamine  and  mignonette,  are  too  delicate  to  bear 
heat,  and  for  these  the  process  of  absorption,  or  "  enfleurage,"  as  it  is  called 
in  the  south  of  France,  is  employed.  Sheets  of  glass  in  wooden  frames, 
called  chcissis,  are  coated  on  their  upper  and  lower  surfaces  with  grease 
about  a  tenth  of  an  inch  in  thickness.  The  flowers  are  spread  upon  this 
grease,  and  a  number  of  frames  are  superimposed  on  each  other.  After  a 
day  or  two  the  flowers  are  carefully  removed  and  replaced  by  fresh  ones, 
and  this  is  continued  for  two  or  three  months,  till  the  fat  is  impregnated 
with  the  odors.  It  is  then  removed  and  extracted  with  alcohol.  Recently 
the  grease  has  been  replaced  in  some  cases  by  soft  paraffine,  glycerine,  or 
vaseline. 

For  the  extraction  by  solvents,  alcohol,  ether,  petroleum-naphtha,  and 
notably  carbon  disulphide  are  employed,  and  the  solvent  recovered  by 
distillation.  The  essential  oils  of  lemons  and  oranges  of  commerce,  and  of 
some  other  fruits,  are  chiefly  obtained  by  submitting  the  rind  to  powerful 
pressure.  The  oils  are  more  fragrant  but  not  so  white  as  when  distilled, 
and  the  process  is  only  adapted  for  substances  which  are  very  rich  in  essen- 
tial oils.  Flowers  with  very  delicate  perfume,  such  as  those  of  the  bitter 
orange,  violets,  etc.,  which  would  be  spoiled  by  distillation,  are  treated  by 
this  method.  The  medium  used  for  infusion  is  clarified  beef  or  mutton 
suet  or  lard.  The  fat  is  melted,  the  flowers  immersed,  and  the  mixture 
stirred  occasionally  for  a  day  or  so.  The  exhausted  flowers  are  removed 
and  fresh  ones  introduced,  and  such  renewals  are  continued  till  it  is  judged 
that  the  fat  is  sufficiently  charged  with  the  oil. 


EAW  MATERIALS.  95 

The  essential  oils  are  usually  more  limpid  and  less  unctuous  than  the 
fixed  oils,  but  some  of  them,  when  in  the  crude  state,  may  be  quite  thick  or 
even  semi-solid  from  admixtures  of  solid  and  crystalline  ingredients  with 
the  more  liquid  portion.  Their  odor  is  that  of  the  plants  which  yield  them, 
and  is  usually  powerful ;  their  taste  is  pungent  and  burning.  They 
mix  in  all  proportions  with  the  fixed  oils,  dissolve  in  both  alcohol  and  ether, 
and  are  sparingly  soluble  in  water,  forming  "perfumed"  or  "medicated 
water."  They  are  not  saponifiable.  Their  boiling-points  usually  range 
from  310°  to  325°  F.  (154.5°  to  162.7°  C.),  although  in  some  oils  the 
hydrocarbons  boil  at  356°  F.  (180°  C.)  or  even  higher.  They  are,  how- 
ever, capable  in  most  cases  of  being  distilled  in  a  current  of  steam.  In 
specific  gravity  they  vary  from  oil  of  citron  .850  to  oil  of  winter-green  1.185 
at  15°  C. 

Chemically,  essential  oils  may  be  divided  into  the  three  great  classes, — 
oils  composed  of  hydrocarbons  only ;  oils  containing  oxygenated  compounds, 
and  oils  containing  sulphur  compounds.  We  will  note  briefly  the  more 
important  illustrations  of  each  of  these  three  classes. 

I.  The  oils  which  do  not  contain  oxygen  are  composed  of  hydrocar- 
bons of  what  is  called  the  terpene  series.  These  seem  to  be  of  a  common 
formula,  which  is  C10H16  or  a  multiple  of  this.  We  may  distinguish  several 
groups. 

1.  Hemiterpenes,  C5H8. — A  hydrocarbon  of  this   formula  is  yielded 
when  caoutchouc  is  destructively  distilled. 

2.  Terpenes,  C10H16. — The  true  terpenes.     Of  these  some  six  or  eight 
distinct  compounds  have  been  obtained,  but  they  may  exist  in  different 
physical  modifications  according  as  they  are  right  or  left  rotatory  or  in- 
active to  polarized  light. 

3.  Sesquiter penes ,  C15H24. — This  group  includes  the  hydrocarbons  of 
oils  of  cedar,  cubebs,  and  cloves. 

4.  Diterpenes,  C20H32,  includes  colophene,  obtained  in  the  treatment  of 
oil  of  turpentine,  and  possibly  others. 

5.  Polyterpenes,  (C10H16)n,  includes  the  polymerized  hydrocarbons  of 
caoutchouc  and  gutta-percha. 

II.  The  oils  which  contain  oxygen  may  owe  this  to  one  of  several 
classes  of  oxygen  compounds. 

1.  Camphors. — This  group  includes  common  or  Japan  camphor,  bor- 
neol,  cineol,  or  eucalyptol,  menthol.     These  bodies  are  either  alcohols  or 
ketones  in  chemical  character. 

2.  Unsaturated  Alcohols  and  Aldehydes. — A  number  of  compounds  of 
this  class  have  recently  been  identified  as  constituting  important  odoriferous 
principles  in  oils.     Thus,  geraniol,  or  rhodinol  and  linalool  (coriandrol)  are 
unsaturated  alcohols,  while  citral  and  citronellal  are  unsaturated  aldehydes. 

3.  Esters  or  Compound  Ethers  of  Alcohols. — The  formic,  acetic,  and 
valeric  ethers  of  borneol  and  the  formic  and  acetic  ethers  of  linalool  and 
geraniol  are  all  found  natural  in  essential  oils.    Methyl  salicylate  is  another 
compound  ether,  constituting  the  main  constituent  of  oil  of  wintergreen. 

4.  Phenols. — Thymol,  of  oil  of  thyme,  and  carvacrol,  of  origanum  oil, 
belong  to  this  class. 

5.  Ethers  of  the  Phenols. — Anethol,  of  anise  oil,  eugenol,  of  oil  of  cloves, 
and  safrol,  of  oil  of  sassafras,  belong  here. 

6.  Aromatic  Aldehydes. — Benzaldehyde,  salicyl  aldehyde,  anisic  alde- 
hyde, vanillin,  cumin  aldehyde,  and  cinnamic  aldehyde  belong  to  this  class. 


96  INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

III.  The  oils  which  contain  sulphur  seem  to  belong  to  two  classes. 

1 .  Sulphides  of  Organic  Radicals. — Garlic  oil,  onion  oil,  leek  oil,  and 
similar  oils  contain  allyl  and  vinyl  sulphides. 

2.  Sulphocyanates  of  Organic  Radicals. — Mustard  oil  and  some  others 
contain  allyl  sulphocyanate. 

Oil  of  Turpentine. — This  oil  is  produced  by  all  the  Conifera  in  greater  or 
less  amount.  It  flows  from  cuts  in  the  tree  as  a  balsam  (see  p.  97),  known 
as  turpentine.  This,  on  distillation  with  steam,  yields  the  volatile  oil  of 
turpentine,  and  there  remains  behind  the  resin  (colophony  resin)  commonly 
known  as  "  rosin."  While  a  number  of  minor  varieties  of  turpentine  are 
known,  such  as  Venetian,  Hungarian,  Strasburg,  Chios  turpentines,  and 
Canada  balsam,  which  are  of  pharmaceutical  value,  but  three  commercially 
important  varieties  of  oil  of  turpentine  need  be  noted.  They  are  English 
or  American  oil  of  turpentine,  from  Pinus  australis  and  Pinus  tceda,  col- 
lected in  North  and  South  Carolina  and  Georgia ;  the  French  oil  of  tur- 
pentine from  Pinus  maritimay  collected  in  the  neighborhood  of  Bordeaux  ; 
and  the  Russian  or  German  oil  of  turpentine,  from  Pinus  sylvestris.  Of 
the  American  oil,  only  seventeen  per  cent,  is  obtained  on  distillation  of  the 
crude  turpentine  balsam  ;  of  the  French,  as  much  as  twenty-five  per  cent, 
of  oil  may  be  obtained ;  and  of  the  Russian,  thirty-two  per  cent.  The 
essential  composition  of  all  three  of  these  oils,  when  rectified,  is  C10H16,  but 
distinct  hydrocarbons,  differing  in  physical  if  not  in  chemical  characters,  are 
considered  to  be  present  in  each  of  the  three  oils.  Thus  the  terpene,  C10H16, 
of  French  oil  of  turpentine  is  Isevo-rotatory,  and  is  known  as  Isevo-pinene, 
while  that  of  the  American  oil  is  dextro-rotatory,  and  is  known  as  dextro- 
pinene.  Otherwise  they  are  practically  identical  in  properties.  Russian  oil 
of  turpentine  consists  mainly  of  a  hydrocarbon,  sylvestrene,  which  boils  some 
sixteen  to  twenty  degrees  Centigrade  higher  than  the  others,  and  shows  some 
other  minor  differences.  The  commercial  oil  of  turpentine  is  a  colorless, 
very  mobile,  highly  refracting  liquid,  of  pleasant  odor  when  freshly  rectified, 
but  becoming  disagreeable  by  exposure  to  the  air,  as  it  absorbs  oxygen  and 
becomes  resinous.  It  is  almost  wholly  insoluble  in  water,  glycerine,  and 
dilute  alkaline  and  acid  solutions.  It  is  soluble  in  absolute  alcohol,  ether, 
carbon  disulphide,  benzene,  petroleum  spirit,  fixed  and  essential  oils.  It  is 
itself  a  solvent  for  sulphur,  phosphorus,  resins,  fats,  waxes,  caoutchouc,  eta 

Turpentine  yields  a  number  of  interesting  and  medicinally  important 
derivatives  under  the  influence  of  different  reagents.  Thus,  by  the  action 
of  hydrochloric  acid  gas  is  formed  pinene  hydrochloride,  C10H17C1,  known 
as  "  artificial  camphor/7  because  of  its  appearance  and  odor.  When  heated 
with  soaps  or  weak  alkali,  it  splits  off  hydrochloric  acid  again  and  leaves 
camphene,  C10H16.  When  turpentine  oil  stands  in  contact  with  water,  es- 
pecially in  the  presence  of  nitric  acid  and  alcohol,  it  unites  with  three 
molecules  of  water  to  form  a  hydrate,  C10H18(OH)2  +  H2O,  known  as  terpin 
hydrate.  This  is  in  colorless  rhombic  prisms  of  slightly  aromatic  and 
somewhat  bitter  taste,  melting  at  116°-117°.  When  the  anhydrous  terpin, 
C10H18(OH)2,  obtained  in  this  fusion  is  distilled  with  dilute  sulphuric  acid 
it  loses  a  molecule  of  water  and  yields  terpineol,  C10H17(OH),  an  oil  of 
hyacinthine  odor  which  is  used  in  medicine.  When  sulphuric  acid  is 
allowed  to  stand  in  contact  with  oil  of  turpentine  and  the  mixture  after  a 
day's  standing  is  heated  to  boiling,  the  oil  is  changed  into  an  optically 
inactive  mixture  of  terpenes,  known  as  terebene,  which  boils,  according  to 
the  United  States  Pharmacopoeia,  at  156°-160°. 


KAW  MATERIALS.  97 

Camphor. — This  is  one  of  the  most  important  of  the  oxidized  principles 
which  were  referred  to  as  accompanying  the  hydrocarbons  in  the  crude  essen- 
tial oils.  While  the  name  is  frequently  used  to  designate  a  class  of  com- 
pounds, it  is  commercially  restricted  to  the  laurel  camphor,  C10H16O,  which  is 
obtained  from  the  wood  of  the  Japan  camphor-tree  (Camphor  a  officinarum)  by 
distillation  with  water  and  after  purification  with  sublimation.  It  forms 
a  colorless,  translucent,  tough,  fibrous  mass,  but  may  be  obtained  crystal- 
lized in  prisms.  It  has  a  peculiar,  fragrant  odor  and  burning  jtaste.  It 
melts  at  347°  F.  (175°  C.),  and  boils  at  399.2°  F.  (204°  C.).  It  is  nearly 
insoluble  in  water,  but  readily  soluble  in  alcohol,  ether,  acetone,  carbon 
disulphide,  chloroform,  and  oils. 

Borneol  (or  Borneo  camphor),  cineol  (or  eucalyptol),  linalool,  and  geraniol 
are  camphors  with  the  formula  C10H18O.  They  occur  either  free  or  in  the 
form  of  esters  in  many  of  the  essential  oils. 

Menthol,  C10H20O,  is  a  white,  camphor-like  body  found  in  peppermint 
oil,  from  which  it  may  be  chilled  out.  It  is  largely  used  in  medicine  and 
pharmacy. 

Thymol,  C10HUO,  found  in  a  number  of  essential  oils,  is  a  solid  phenol. 

2.  RESINS. — The  resins  are  products  of  the  oxidation  of  the  terpenes,  and 
either  accompany  them  in  the  crude  essential  oils  or  occur  as  exudations 
from  trees  hardening  on  exposure  to  the  air.  The  classification  of  resins 
usually  adopted  at  present  is  into  (1)  true  resins,  (2)  gum  resins,  and  (3) 
oleo-resins  or  balsams.  The  true  resins  are  hard,  compact  products  of 
oxidation,  made  up  chiefly  of  what  are  termed  "  resin  acids,"  which,  admixed 
with  fatty  acids,  are  capable  of  saponifying  with  alkalies  and  yield  "  rosin 
soaps"  (see  p.  64)  ;  the  gum  resins  differ  from  the  true  resins  only  in  con- 
taining some  gum  capable  of  softening  in  water  ;  and  the  oleo-resins  include 
the  mixtures  of  essential  oil  and  resin  of  whatever  consistency  and  the  mix- 
tures of  benzoic  and  cinnamic  acid  and  salts  of  these  acids.  This  last  class  is 
obviously  much  the  largest  of  the  three.  To  the  first  class  belong  the  hard 
resins,  which  serve  for  the  manufacture  of  varnishes,  such  as  copal,  dammar, 
mastic,  sandarach,  dragon's  blood,  gum  lac,  and  amber ;  to  the  second  class, 
olibanum  or  frankincense,  myrrh,  ammoniacum,  asafcetida,  galbanum,  and 
tragacanth ;  and  to  the  third  class,  crude  turpentine,  benzoin,  storax, 
copaiba,  Peru  and  Tolu  balsams.  Brief  mention  will  be  made  of  a  few  of 
the  commercially  more  important. 

Amber  is  a  fossil  resin  found  in  detached  pieces  on  the  sea-coast,  and 
particularly  in  the  blue  earth  along  the  Baltic  coast  of  Prussia,  between 
Konigsberg  and  Memel.  Its  applications  are  chiefly  as  an  article  for  the 
manufacture  of  mouth-pieces  of  pipes  and  cigar-holders  and  for  beads,  for 
the  preparation  of  a  superior  varnish,  and  for  the  production  of  amber  oil 
and  succinic  acid. 

Gum  Arabic. — This  is  included  among  gum  resins  because  an  exuda- 
tion analogous  to  other  resins,  but  is  almost  wholly  a  gum,  soluble  in  water, 
and  closely  related  chemically  to  the  starch  group.  (See  p.  168.)  It  is 
yielded  by  the  different  species  of  Acacia,  and,  at  present,  comes  chiefly  from 
Central  and  North  Africa,  by  way  of  Egypt,  Senegal,  and  the  Red  Sea.  It 
varies  greatly  in  purity  and  color,  and  is  used,  because  of  its  mucilaginous 
character,  for  a  multitude  of  applications,  as  in  medicine,  confectionery, 
preparation  of  textile  fabrics,  manufacture  of  inks,  etc. 

Copal  and  Anime. — These  terms  include  a  number  of  related  resins,  which 
are  of  both  fossil  and  recent  origin.  The  Zanzibar  copal  or  anime"  is  chiefly 

7 


98  INDUSTRY  OF  THE  ESSENTIAL  OILS  AND   RESINS. 

fossil,  and  is  dug  out  of  the  soil  by  the  natives  for  some  distance  along  the 
southeastern  coast  of  Africa.  Some  freshly-exuded  copal  resin  is  also  gathered 
here.  On  the  west  coast  of  Africa,  for  a  distance  of  seven  hundred  miles, 
copal  resin  is  also  dug  as  a  fossil.  When  of  good  quality  it  is  too  hard  to 
be  scratched  by  the  nail,  has  a  conchoidal  fracture,  and  a  specific  gravity 
ranging  from  1.059  to  1.080.  Unlike  others,  the  copal  resins  are  soluble 
with  difficulty  in  alcohol  and  essential  oils,  and  this  property,  combined 
with  their  extreme  hardness,  renders  them  very  valuable  for  making 
varnishes. 

Dammar  is  obtained  from  the  Dammara  orientalis,  a  coniferous  tree, 
indigenous  in  the  East  Indies  and  Moluccas,  and  also  from  Dammara 
australis,  in  New  Zealand.  The  two  varieties  are  known  as  East  Indian 
and  Australian  dammar,  the  latter  being  also  known  as  Kauri  resin.  The 
former  is  that  commonly  met  with  in  commerce  under  the  simple  name  of 
dammar.  The  resin  occurs  in  masses,  coated  on  the  exterior  with  white 
powder  from  mutual  attrition,  while  the  interior  is  pale  amber-colored  and 
transparent.  It  is  scratched  by  copal,  but  is  harder  than  rosin.  The  resin 
splits  and  cracks  at  the  temperature  of  the  hand.  The  Kauri  variety  is  chiefly 
fossil  in  its  origin.  The  dammar  is  extensively  used  in  the  manufacture  of 
varnishes. 

Lao  is  a  resinous  incrustation  produced  on  the  bark  of  the  twigs  and 
branches  of  various  tropical  trees,  by  the  puncture  of  the  female  "  lac  in- 
sect" (Coccus  lacca).  This  crude  exudation  constitutes  the  stick-lac  of  com- 
merce. Shell-lac  or  shellac  is  prepared  by  spreading  the  resin  into  thin 
plates  after  being  melted  and  strained.  In  the  preparation  of  the  shellac, 
the  resin  is  freed  from  the  coloring  matter,  which  is  formed  into  cakes,  and 
is  known  as  "  lac-dye."  "  Button-lac"  diifers  from  shellac  only  in  form. 
Instead  of  being  drawn  over  a  cylinder,  the  melted  lac  is  allowed  to  fall 
upon  a  flat  surface,  and  assumes  the  shape  of  large  cakes  about  three  inches 
in  diameter  and  one-sixth  inch  thick.  Bleached  lac  is  prepared  by  dis- 
solving lac  in  a  boiling  lye  of  pearl-ash  or  caustic  potash,  filtering  and  pass- 
ing chlorine  through  the  solution  until  all  the  lac  is  precipitated.  This  is  then 
collected,  well  washed,  and  pulled  in  hot  water,  and  finally  twisted  into 
sticks  and  thrown  into  cold  water  to  harden. 

Seed-lac  is  the  residue  obtained  after  dissolving  out  most  of  the  coloring 
matter  contained  in  the  resin.  The  common  shellac  is  used  in  varnishes, 
lacquers,  and  sealing-wax ;  the  bleached  lac  in  pale  varnishes  and  light- 
colored  sealing-wax. 

Mastic  is  the  resin  flowing  from  the  incised  bark  of  the  Pistacia 
lentiscus,  and  comes  exclusively  from  the  Island  of  Chios,  in  the  Mediter- 
ranean. It  comes  into  commerce  in  pale,  yellowish,  transparent  tears, 
which  are  brittle,  with  conchoidal  fracture,  balsamic  odor,  and  softens  be- 
tween the  teeth.  It  is  soluble  in  alcohol,  oil  of  turpentine,  and  acetone. 
It  is  used  in  varnish-making. 

Colophony  Resin  (rosin)  is  the  solid  residue  left  on  distilling  oif  the 
volatile  oil  from  the  crude  turpentine.  The  resins  from  the  Bordeaux  tur- 
pentine and  that  from  the  American  turpentine  are  substantially  identical. 
Rosin  is  a  brittle,  tasteless,  very  friable  solid,  of  smooth,  shining  fracture, 
specific  gravity  about  1.08.  It  softens  at  80°  C.  (176°  F.),  and  fuses  com- 
pletely to  a  limpid  yellow  liquid  at  135°  C.  (275°  F.). 

It  is  insoluble  in  water,  difficultly  soluble  in  alcohol,  but  freely  soluble 
in  ether,  acetone,  benzene,  and  fatty  oils.  With  boiling  alkalies  it  takes  up 


RAW  MATERIALS.  99 

water  to  form  abietic  acid,  and  then  unites  with  the  alkali  to  form  a  rosin 
soap.     (See  p.  63.) 

3.  CAOUTCHOUC  (India-rubber). — This  is  the  chief  substance  contained 
in  the  milky  juice  which  exudes  when  a  number  of  tropical  trees  belonging 
to  the  natural  orders  Euphorbiacete,  Artocarpacece,  and  Apocynacece  are  cut. 
This  juice  is  a  vegetable  emulsion,  the  caoutchouc  being  suspended  in  it  in 
the  form  of  minute  transparent  globules.     The  emulsion  is  easily  coagulated, 
and  the  caoutchouc  caused  to  separate  by  the  addition  of  alum,  saltsojutions, 
and  other  means 

Caoutchouc  belongs  in  the  same  general  category  as  the  essential  oils,  as 
it  possesses  the  general  formula  (C10H16)n,  and  is,  hence,  a  polymer  of  the 
terpene  formula  C10H16.  On  submitting  it  to  destructive  distillation  it 
yields  caoutchin,  C10H16,  boiling  at  171°  C.,  and  isoprene,  C5H8,  boiling  at 
38°  C. 

The  different  species  of  rubber-trees  are  cultivated  in  Mexico,  South 
America,  and  the  West  Indies,  in  the  East  Indies,  Borneo,  Sumatra,  and 
the  African  coast. 

The  commercial  varieties  of  caoutchouc  may  be  grouped  under  four 
heads,  the  relative  value  of  which  accords  with  the  order  in  which  they  are 
placed :  South  American :  Para,  Ceara,  Carthagena,  Guayaquil ;  Central 
American :  West  Indian,  Guatemala  ;  African :  Madagascar,  Mozambique, 
West  African  ;  Asiatic :  Assam,  Borneo,  Rangoon,  Singapore,  Penang,  and 
Java.  The  Para  rubber  (from  the  Hevea  Brasiliensis  or  Siphonia  elastica)  is 
the  best  of  the  many  varieties,  and  commands  the  highest  price. 

Caoutchouc,  when  pure,  is  nearly  white,  but  the  commercial  varieties 
are  discolored  by  smoke  in  the  drying  of  the  freshly-exuded  juice  in  the 
methods  usually  followed.  At  ordinary  temperatures  caoutchouc  is  soft, 
elastic,  and  so  glutinous  that  two  freshly-cut  surfaces  pressed  strongly 
together  will  permanently  adhere.  At  low  temperatures  it  is  harder,  is 
less  elastic  and  adhesive,  while,  on  heating  it,  the  elastic  property  disap- 
pears also,  and  it  becomes  perfectly  soft  and  can  be  kneaded.  In  water 
caoutchouc  swells  up  without  dissolving ;  in  ether,  petroleum-naphtha, 
benzene,  carbon  disulphide,  oil  of  turpentine,  rosin  oil,  and  oils  gotten  by  the 
dry  distillation  of  the  rubber  itself,  the  caoutchouc  swells  up  rapidly,  and 
after  a  time  dissolves  to  a  greater  or  less  degree.  The  best  solvents  are 
carbon  disulphide  and  chloroform,  and  Payen  recommends  carbon  disul- 
phide, to  which  five  per  cent,  of  absolute  alcohol  has  been  added,  as  excel- 
lent. Caoutchouc  is  quite  indifferent  to  most  chemical  reagents,  but  is 
attacked  by  strong  nitric  and  sulphuric  acids.  Fatty  matters  present  in  the 
solvents  used  seem  to  have  a  deleterious  action  upon  the  caoutchouc,  causing 
it  to  become  first  soft  and  afterwards  hard  and  brittle.  Caoutchouc  softens 
at  120°  C.,  melts  at  about  150°  C.,  and  decomposes  at  200°  C. 

4.  GUTTA-PERCHA   AND    SIMILAR  PRODUCTS. — Gutta-percha  is  ob- 
tained from  the  milky  juice  of  different  trees  of  the  genus   Isonandra, 
belonging  to  the  natural  order  Sapotacece.     By  the  coagulation  of  the  col- 
lected juice  the  gutta-percha  globules  mass  together  and  can  be  kneaded 
into  lumps.      The  localities  in  which  the  gutta-percha  is  cultivated  are 
Borneo,  Sumatra,  and  the  Malayan  Archipelago.     It  comes  into  commerce 
in  irregularly-  and  fancifully-formed  blocks.     It  forms  a  fibrous  mass,  vary- 
ing in  color  from  nearly  white  to  reddish  or  brownish,  looking  something 
like  leather  clippings  cemented  together,  and  has  a  specific  gravity  of  .979. 
At  ordinary  temperatures  it  is  hard  and  somewhat  elastic,  at  25°  C.  (77°  F.) 


100          INDUSTRY  OF  THE   ESSENTIAL  OILS  AND   RESINS. 

it  becomes  soft,  and  at  50°  C.  (122°  F.)  it  can  be  kneaded  or  rolled  out 
into  plates.  Between  55°  C.  and  60°  C.  it  is  so  thoroughly  plastic  as  to  be 
drawn  into  tubes,  thread,  plates,  and  at  120°  C.  (248°  F.)  it  melts.  Its 
elasticity  seems  distinctly  greater  in  the  direction  of  its  fibre  than  in  an 
opposite  one,  while  caoutchouc  is  equally  elastic  in  all  directions.  Gutta- 
percha  is  a  poorer  conductor  of  electricity  than  caoutchouc,  and  hence  its 
extensive  use  in  insulating  wires  and  cables.  Its  power  of  softening  at  45° 
C.  is  partly  overcome  by  the  process  of  vulcanization  or  union  with  sulphur. 
Chemically,  gutta-percha  seems  to  be  composed,  like  caoutchouc,  of  a  hydro- 
carbon (C10H16)n,  but  is  always  accompanied  by  a  certain  amount  of  oxida- 
tion products.  Pay  en  found  that  the  crude  gutta-percha,  after  thorough 
exhaustion  with  alcohol,  left  seventy-eight  to  eighty-two  per  cent,  of  a  pure 
hydrocarbon,  that  he  termed  gutta,  which,  at  from  15°  C.  to  30°  C.  (59°  to 
86°  F.),  was  tenacious  and  ductile,  but  not  very  plastic. 

Balata  is  the  dried,  milky  juice  of  the  bully-tree  (Sapota  Miller  i),  which 
flourishes  in  Guiana.  The  balata  is  obtained  from  the  juice  in  a  manner 
similar  to  gutta-percha.  In  its  properties  it  is  intermediate  to  caoutchouc 
and  gutta-percha ;  it  is  more  plastic  and  readily  kneaded  than  the  former 
and  more  elastic  than  the  latter.  At  ordinary  temperatures  it  is  compact 
and  horny,  but  at  49°  C.  already  it  becomes  soft,  and  can  be  shaped. 
Towards  solvents  it  behaves  like  gutta-percha. 

It  is  used  chiefly  in  England  as  a  substitute  for  gutta-percha  and 
caoutchouc,  and  is  also  used  as  an  addition  to  these.  Towards  chloride  of 
sulphur  and  metallic  sulphides  it  acts  like  caoutchouc  and  gutta-percha. 

5.  NATURAL  VARNISHES. — This  term  is  applied  to  a  class  of  natural 
products  which  are  resinous  exudations,  capable  of  direct  use  as  varnishes 
or  lacquers.  The  most  important  are  : 

(1)  Burmese  lacquer,  a  thick,  grayish   terebinthinous  liquid,  collected 
from  the  Melanorrhcea  usitatissima  of  Burmah.     It  dissolves  in  alcohol, 
turpentine  oil,  and  benzene,  assuming  greater  fluidity.     Locally,  it  is  used  in 
enormous  quantities  in  lacquering  furniture,  temples,  idols,  and  varnishing 
vessels  for  holding  liquids. 

(2)  Cingalese  and  Indian  lacquer,  a  black  varnish  obtained  in   Ceylon 
and  India  from  Semicarpus  anarcardium,  and  in   Madras,  Bombay,  and 
Bengal,  from  Holigarua  longifolia.    It  forms  an  excellent  varnish,  adhering 
strongly  to  wood  and  metal. 

(3)  Japanese  and  Chinese  lacquer  is  derived  from  several  species  of  Rhus, 
whose  fruits  form  the  Japan  wax  of  commerce.    (See  p.  51.)    It  is  purified 
by  defecation  and  straining,  and  mixed  with  coloring  matter,  if  needed.     It 
is  most  extensively  used  in  Japanese  and  Chinese  lacquer-work. 

n.  Processes  of  Treatment. 

1.  MANUFACTURE  OF  PERFUMES  AND  SIMILAR  PRODUCTS. — In  the 
use  of  essential  oils  or  mixtures  of  them,  as  the  basis  of  agreeable  smelling 
preparations  or  perfumes,  several  classes  of  preparations  may  be  distin- 
guished :  (1)  Perfumed  waters  or  alcoholic  solutions  of  mixed  essential 
oils  ;  (2)  odoriferous  extracts  or  alcoholic  extracts  from  fatty  oils  charged 
with  odors  by  "  enfleurage"  or  maceration  ;  and  (3)  pomades  and  per- 
fumed soaps.  In  the  manufacture  of  the  first  class  of  preparations,  the 
alcohol  to  be  used  must  be  free  from  fusel-oil  and  thoroughly  deodorized. 
The  essential  oils  may  be  in  part  dissolved  separately  in  the  alcohol  or 


PROCESSES  OF  TREATMENT.  101 

added  together  to  the  proper  quantity  of  the  solvent  according  to  the  nature 
of  the  materials.  Long-continued  standing  of  the  alcoholic  solutions  is  now 
considered  sufficient  to  effect  a  thorough  amalgamation  and  development  of 
the  desired  perfume,  and  distillation  is  dispensed  with.  As  examples  of  such 
perfumes  we  have  the  well-known  cologne  waters  and  eau  de  mille  fleurs. 

The  odoriferous  extracts  are  gotten  by  treating  with  alcohol  the  fatty 
oils  and  fats  which  have  been  charged  with  the  perfumes  of  flowers  by  the 
"  enfleurage"  process.  Glycerine,  soft  paraffine,  and  vaseline  hav.e  latterly 
been  used  too  in  the  extraction  of  the  odors.  On  chilling  the  alcohol  by 
freezing  mixtures  or  other  means  to  18°  C.,  the  fat  is  separated  out  and 
gotten  rid  of. 

Pomades  are  made  from  fatty  oils,  the  basis  usually  being  oil  of  almonds, 
oil  of  ben,  or  olive  oil.  The  processes  for  preparing  these  scented  fats  are 
those  of  infusion  with  warm  fatty  oils  or  melted  fats  at  a  temperature  of 
about  65°  C.,  and  of  "  enfleurage,"  or  cold  perfuming,  as  already  described. 
The  analogous  class  of  compounds,  perfumed  soaps,  have  been  spoken  of 
under  another  heading.  (See  p.  76.) 

2.  MANUFACTURE  OF  VARNISHES. — Very  much  more  important,  in 
an  industrial  sense,  is  this  application  of  essential  oils  and  resins.  Under 
the  name  varnish  is  generally  understood  either  a  solution  of  a  resin  or  a 
rapidly  resinifying  oil,  which,  when  applied  to  solid  bodies,  becomes  dry 
and  hard,  either  by  evaporation  of  the  solvent  or  a  drying  and  oxidation  of 
the  same,  while  the  film  of  resin  left  behind  makes  a  hard,  glossy  coating, 
impervious  to  air  and  moisture.  Varnishes  may  be  of  three  classes,  ac- 
cording to  the  character  of  the  solvent  used  for  the  resin  :  (1)  Linseed-oil 
varnishes,  in  which  boiled  linseed  oil  is  used ;  (2)  spirit  varnishes,  in  which 
alcohol  or  petroleum  spirit  is  used ;  (3)  turpentine-oil  varnishes. 

Linseed-oil  Varnishes. — Linseed  oil  itself,  as  a  drying  oil  (see  p.  49),  is 
capable  of  forming  a  varnish  without  the  addition  of  a  resin.  For  the 
preparation  of  varnish,  the  oil  must  first  be  boiled.  When  heated  to 
130°  C.  it  begins  to  boil,  but  the  heat  is  continued  until  it  shows  about 
260°  C.  (500°  F.),  which  temperature  should  not  be  much  exceeded.  It 
absorbs  oxygen  in  this  process  and  becomes  thick  and  glutinous.  The  ab- 
sorption of  oxygen  and  the  thickening  of  the  oil  are  much  accelerated  by 
the  use  of  driers  like  litharge,  manganese  dioxide,  lead  acetate,  manganese 
borate,  etc.  (See  p.  74.)  Boiling  linseed  oil  over  free  fire,  as  it  is  generally 
carried  on,  is  illustrated  in  Fig.  34.  Care  should  be  taken  that  the  kettle 
is  not  filled  so  full  as  to  allow  it  to  boil  over  when  strongly  heated.  The 
lid  e,  ordinarily  raised,  can  be  lowered  upon  it  if  the  escaping  decomposi- 
tion products  catch  fire. 

In  Fig.  35  is  shown  a  pair  of  kettles  arranged  for  boiling  the  linseed 
oil  by  steam.  Pressures  of  four  and  a  half  to  five  atmospheres  are  used  for 
the  steam  in  this  case,  and  a  temperature  of  132°  C.  (269.6°  F.)  yielding  a 
perfectly  clear,  light-colored  varnish.  When  boiled  so  as  to  have  lost  one- 
twelfth  of  its  weight  it  yields  the  ordinary  boiled  oil  varnish ;  if  heated 
until  it  loses  one-sixth  of  its  weight  it  becomes  thicker  and  yields  a  stiff 
varnish,  which  is  used  as  the  basis  of  printer's  ink.  (See  p.  104.)  The 
specific  gravity  of  boiled  linseed  oil  of  good  quality  varies  from  .940  to 
.950,  and  on  ignition  it  leaves  a  mineral  residue  of  from  .2  to  .4  per  cent. 
Experiment  has  taught  that  oxidation  proceeds  the  more  rapidly  when  it  is 
pushed  rapidly ;  or,  in  other  words,  in  order  to  change  linseed  oil  into  var- 
nish by  atmospheric  exposure,  it  must  be  brought  to  boiling  as  rapidly  as 


102          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

possible.  What  takes  place  in  this  case  is  not  an  evaporation  simply,  but 
a  decomposition  of  the  linolein  (glyceride  of  linoleic  acid)  takes  place, 
whereby  glycerine  separates,  and  a  portion  of  the  linoleic  acid  changes  into 
linoleic  anhydride,  C32HMO31,  an  elastic  and  caoutchouc-like  mass  (see  p. 
Ill),  which  then  dissolves  in  the  undecomposed  linseed  oil  and  gives  the  oil 
its  valuable  varnish-forming  and  drying  character.  Another  part  of  the 


FIG. 


linoleic  acid,  liberated  by  the  boiling,  absorbs  oxygen  and  changes  into 
oxylinoleic  acid,  C16H26O5,  which  at  first  is  of  turpentine-like  character, 
while  all  undecomposed  glyceride  of  linoleic  acid  dries  up  to  elastic  linoxyn, 
CjpH^On.  A  good  varnish,  therefore,  is  made  up  of  three  factors  :  (1)  Lino- 
leic anhydride,  (2)  oxylinoleic  acid,  and  (3)  linoxyn. 

These  views  of  Mulder  as  to  the  changes  which  occur  in  the  boiling  of 


PROCESSES  OF  TREATMENT. 


103 


linseed  oil  are  controverted  by  Bauer  and  Hazura,*  who  consider  that  the 
liquid  fatty  acids  of  linseed  oil  consist  of  eighty  per  cent,  of  linolenic  and 
isolinolenic  acids  (C^H^Og),  together  with  nearly  twenty  per  cent,  of  linoleic 
acid  (C^H^Og),  and  small  quantities  of  oleic  acid  (C18H34O2).  They  con- 


FIG.  35. 


FIG.  36. 


sider  Mulder's  oxylinoleic  acid  to  have  been  a  mixture,  and  state  that  the 
more  linolenic  acid  an  oil  contains,  the  more  quickly  it  dries. 

The  pure  linseed-oil  varnish  so  prepared  may  then  serve  for  the  prepa- 
ration of  what  are  termed  lacquers  or  solutions  of  resins  in  linseed-oil  var- 
nish, thinned  out  ordinarily  with  turpentine  oil  or  benzine.  Of  the  resins, 
amber,  copal,  amine",  dammar,  and  asphalt  are  used  for  these  lacquers.  In 
order  to  prepare  these  varnishes,  the  resins,  amber,  copal,  etc.,  are  fused  in  a 
kettle  placed  over  a  coal-fire  in  such  a  way  that  it  sinks  into  the  fire-chamber 
but  a  slight  distance,  and  the  flame  can  touch  the  bottom  of  the  kettle  only. 
After  the  resin  has  fused,  the  proper  amount  of  boiling  linseed-oil  varnish  is 
added,  care  being  taken  that  the  mixture  does  not  fill  the  kettle  to  more  than 
two-thirds  at  the  most,  and  the  contents  then  boiled  for  ten  minutes.  When 
the  kettle  has  cooled  down  to  about  140°  C.,  the  necessary  amount  of  tur- 
pentine oil  is  added. 

In  the  case  of  the 
two  resins,  amber  and 
copal,  something  more 
than  a  fusion  is  essen- 
tial. They  are  sub- 
mitted to  a  dry  distil- 
lation, and  only  after 
they  have  given  oif 
from  ten  to  twenty  per 
cent,  of  their  weight  in 
oily  distillation  prod- 
ucts does  the  residue 
become  perfectly  solu- 
ble. A  form  of  still  in 
which  this  distillation  of  resins  is  carried  out  is  shown  in  Fig.  36.  The  cop- 
per still  jg,  which  is  heated  in  this  case  over  the  direct  fire,  is  provided  with 

*  Zeit.  fur  Angew.  Chem.,  1888,  pp.  455-458. 


104  INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

mechanical  agitation,  R,  and  a  tube,  A,  for  drawing  off  the  melted  residue. 
This  tube  is  covered  where  it  projects  through  the  fire  by  fire-brick  to 
protect  it  from  the  flame.  The  distillation  products  escape  through  D  and 
are  condensed  by  the  worm  K.  The  dry  distillation  of  copal  proceeds  best 
at  a  temperature  of  340°  to  360°  C.,  while  that  of  amber  requires  380°  to 
400°  C.  If  heated  higher  than  these  temperatures  the  resins  become  dark. 
As  the  melting-point  of  lead  is  334°  C.,  a  lead  bath  is  recommended  for 
the  copal  distillation. 

These  lacquers  are  the  hardest  and  most  durable  of  varnishes,  but  they 
dry  more  slowly  than  simple  linseed-oil  varnish. 

Spirit  varnishes  are  solutions  of  resins,  such  as  sandarach,  mastic,  dammar, 
gum-lac,  and  shellac,  in  alcohol,  although  this  is  sometimes  replaced  by 
other  solvents,  such  as  methyl  alcohol,  acetone,  and  petroleum  spirit.  The 
spirit  varnishes  dry  rapidly,  leaving  a  brilliant  surface,  but  are  more  apt  to 
crack  and  peel  off  than  turpentine  varnishes.  Turpentine  is  often  added  to 
these  varnishes  to  diminish  this  brittleness.  Among  the  most  important 
varnishes  of  this  class  are  shellac  varnish,  of  which  the  finest  grade  is  pre- 
pared from  bleached  shellac  dissolved  in  alcohol,  and  copal  varnish.  In 
the  preparation  of  this  latter,  the  copal  must  be  first  fused,  or  rather  sub- 
mitted to  dry  distillation  in  the  manner  already  described.  (See  p.  103.) 
The  fused  copal  residue  is  afterwards  powdered,  mixed  with  sand  and 
covered  with  strong  alcohol,  heated  to  boiling  for  some  time  and  then  filtered. 
The  addition  of  elemi  resin  imparts  a  toughness  to  the  copal  varnish. 

Colored  spirit  varnishes  are  made  by  the  addition  of  alcoholic  extracts 
of  annatto,  dragon's  blood,  gamboge,  turmeric,  cochineal,  or  even  solutions 
of  the  different  coal-tar  colors. 

Turpentine-oil  Varnishes. — These  are  prepared  in  the  same  way  as  the 
spirit  varnishes.  They  dry  more  slowly,  but  are  more  flexible  and  durable. 
The  most  important  are  copal  varnish  and  dammar  varnish.  Turpentine 
and  linseed  oil  are  frequently  used  jointly  in  the  preparation  of  varnishes, 
so  as  to  obtain  the  best  results.  Thus,  in  the  manufacture  of  copal  and 
amber  varnishes,  described  before  (see  p.  103),  the  relative  amounts  of  ma- 
terials are :  Ten  parts  of  copal  or  amber  (or  the  residue  from  the  distil- 
lation of  amber  oil),  twenty  to  thirty  parts  of  linseed-oil  varnish,  and 
twenty-five  to  thirty  parts  of  oil  of  turpentine. 

3.  MANUFACTURE  OF  PRINTER'S  INK; — Printer's  ink,  of  whatever 
grade,  whether  for  newspaper  print,  for  book,  lithographic,  or  copperplate 
printing,  is  a  very  stiff,  rapidly-drying  linseed-oil  varnish,  to  which  has  been 
added  lamp-black  or  charcoal  in  the  finest  state  of  division.  For  its  prepara- 
tion, linseed,  poppy,  or  nut  oil  is  heated  in  copper  vessels,  over  a  free  fire  to  a 
temperature  beyond  the  boiling-point,  so  that  inflammable  vapors  are  given 
off.  These  are  frequently  ignited,  or,  as  is  now  preferred,  they  may  be 
allowed  to  escape  into  a  draught  chimney.  The  heating  is  continued  until 
the  oil  becomes  quite  thick  and  a  film  forms  on  the  surface,  which  causes  it 
to  swell  up  with  escaping  bubbles  of  vapor.  A  sample  taken  out  and  tested 
between  the  fingers  should  draw  out  in  long  filaments.  In  this  condition, 
with  the  addition  of  about  sixteen  per  cent,  of  lamp-black,  the  varnish  will 
dry  very  easily  and  rapidly.  If  the  varnish  has  not  been  boiled  long 
enough,  the  printed  characters  will  run  together  and  oil  will  be  absorbed 
in  the  paper  fibre,  so  that  the  printed  letters  will  show  a  yellowish 
border. 

For  the  ink  to  be  used  in  book-printing,  an  addition  of  soap  is  absolutely 


PROCESSES  OF  TREATMENT.  105 

necessary ;  it  allows  the  inked  type  to  be  withdrawn  from  the  moist  paper 
clear  and  sharp  without  any  adhering  or  smearing.  The  finer  the  printed 
work  required  the  stiifer  and  more  thoroughly  boiled  the  varnish  must  be, 
so  that  for  copperplate  and  lithographic  inks  a  much  stiifer  ink  is  needed 
than  that  which  is  used  for  newspaper  or  even  book  printing.  The  ex- 
pensive linseed  oil  is  frequently  replaced  by  hemp-seed,  poppy,  or  nut  oil. 
In  order  to  obviate  the  necessity  of  boiling  the  oil  down  so  thick,  rosin  is 
sometimes  added  to  the  varnish.  Thus,  to  one  hundred  and  twenty  parts  of 
linseed  oil  forty  to  fifty  parts  of  rosin  are  added  and  twelve  to  fourteen  parts 
of  soap.  Rosin  oil  is  also  used  in  place  of  a  part  of  the  linseed  oil ;  indeed, 
cheap  printing  ink  can  be  made  composed  of  rosin  oil,  rosin,  soap,  and 
lamp-black  alone,  without  the  addition  of  linseed  oil  at  all. 

Colored  printing  inks  are  obtained  by  adding  to  the  boiled-oil  varnish 
vermilion,  Prussian  blue,  indigo,  and  other  colors. 

4.  MANUFACTURE  OF  OIL-CLOTH,  LINOLEUM,  ETC. — In  the  manufac- 
ture of  oil-cloths,  the  basis  is  a  coarse  canvas,  of  jute  or  cotton  stuff  usually, 
which  is  coated  with  repeated  layers  of  linseed  oil,  which  has  been  pre- 
viously boiled  sufficiently  with  litharge,  and  to  which  the  coloring  matter 
has  been  added,  or,  in  other  words,  a  linseed-oil  paint.     Before  putting  on 
the  coatings  of  paint,  the  canvas  is  primed  with  a  coating  of  size.     The 
object  of  this  is  not  only  to  give  a  body  to  the  cloth,  but  also  to  protect  the 
fibre  from  the  injurious  action  of  the  acid  products  generated  during  the 
oxidation  of  the  linseed  oil  which  is  subsequently  applied.     Cloth  which  is 
covered  with  paint  without  a  protective  coating  of  size  soon  becomes  rotten 
and  brittle.     Both  sides  of  the  canvas  are  painted  in  this  way.     After  thor- 
ough drying  of  this  layer  a  second  coat  is  applied  to  both  sides.     This 
suffices  for  the  back  of  the  oil-cloth.     The  painting  of  the  face  side  is  con- 
tinued until  it  is  sufficiently  built  up  for  the  printing  of  the  pattern.     Most 
of  the  printing  is  hand-printing  done  by  blocks,  the  number  of  which  cor- 
respond to  the  number  of  colors  to  be  used. 

Linoleum  is  a  name  often  given  to  a  form  of  oil-cloth  in  which 
powdered  cork  and  pigment  are  incorporated  with  a  thoroughly  oxidized 
linseed  oil.  A  pattern  may  then  be  printed  on  and  a  transparent  varnish 
to  cover  all. 

The  oxidized  oil  used  in  linoleum  manufacture  has  sometimes  both 
rosin  and  kauri  gum  added  to  it  to  give  it  toughness.  The  proportions 
for  ordinary  linoleum  are  :  Oxidized  oil,  eight  and  one-half  hundredweight ; 
rosin,  one  hundredweight;  kauri  gum,  one-half  hundredweight.  A  variety 
of  linoleum  containing  wood  fibre  instead  of  ground  cork  has  of  late  years 
been  introduced  as  a  substitute  for  wall-papering  under  the  name  of 
"  lincrusta." 

5.  PROCESSES  OF  TREATMENT  OF  CAOUTCHOUC  AND  GUTTA-PERCHA. 
— The  -crude  rubber  as  brought  into  commerce  is  quite  impure  from  acci- 
dental causes,  and,  in  many  cases,  from  intentional  adulteration.     It,  there- 
fore, must  undergo  a  thorough  mechanical  cleaning  before  being  submitted 
to  any  chemical  treatment.     It  is  first  boiled  with  water  (to  which  a  little 
slaked  lime  is  advantageously  added)  until  thoroughly  softened,  then  cut 
into  slices  and  passed  repeatedly  between  grooved  rollers,  known  as  washing 
rollers,  while  a  stream  of  cold  water  flows  over  it.     This  crushes  and  carries 
away  any  solid  impurities  as  well  as  those  which  are  soluble.     Under  this 
treatment  Para  rubber  loses  from  twelve  to  fifteen  per  cent,  of  its  weight ; 
the  African  variety,  twenty-five  to  thirty-three  per  cent.     After  this  wash- 


106          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

ing,  the  rubber  is  carefully  and  thoroughly  dried.  Neglect  of  this  frequently 
causes  the  wares  when  subsequently  vulcanized  to  appear  spongy.  The 
caoutchouc  is  now  to  be  worked  over  and  agglomerated  thoroughly,  which 
is  done  either  by  passing  it  repeatedly  between  rollers  heated  to  70°  or  80° 
C.,  or  by  the  aid  of  the  so-called  masticating  or  kneading  machine,  which 
consists  of  a  hollow  cylinder  within  which  revolves  another  cylinder  with 
a  fluted  or  corrugated  surface.  The  rubber  being  placed  in  the  annular 
space  between  the  two  cylinders,  the  inner  one  is  made  to  revolve,  whereby 
the  mass  is  worked  over  and  over  and  thoroughly  kneaded.  The  rubber  is 
now  to  be  mixed  with  the  sulphur  needed  for  its  vulcanization  and  with 
whatever  coloring  or  weighting  materials  are  to  be  used.  This  mixing  is 
effected  by  the  aid  of  horizontal  rollers  heated  internally  with  steam,  and  so 
geared  as  to  move  in  contrary  directions  at  unequal  speed.  This  mixed 
rubber  so  obtained  can  readily  be  softened  by  heat,  and  can  now  be  shaped, 
moulded,  or  rolled  into  any  desired  shape,  and  then  submitted  to  the  heat 
necessary  for  vulcanization. 

The  vulcanization  of  rubber  consists  in  effecting  a  combination  of  the 
caoutchouc  with  sulphur  or  sulphides  whereby  the  behavior  of  the  caout- 
chouc towards  heat  and  towards  solvents  is  changed.  Its  value  for  tech- 
nical purposes  is  greatly  increased  by  this  change. 

Two  methods  of  vulcanization  are  to  be  noted :  (1)  the  vulcanizing 
by  mixing  with  sulphur  or  metallic  sulphides  and  heating  to  125°  to  140° 
C. ;  (2)  the  cold  vulcanization  process  of  Alexander  Parkes,  consisting  of 
immersing  the  rubber  articles  in  a  solution  of  chloride  of  sulphur  in  carbon 
disulphide  or  benzene.  The  latter  process  is  only  used  for  small  articles  or 
those  consisting  of  thin  layers  of  caoutchouc,  as  the  action  of  the  chloride 
of  sulphur,  even  in  the  two  and  one-half  per  cent,  solution  usually  em- 
ployed, is  very  rapid,  while  at  the  same  time  it  is  superficial,  so  that  it  is 
difficult  to  control  the  action  properly.  In  vulcanizing  by  the  first  process, 
that  of  "  burning/7  as  it  is  termed,  the  crude  caoutchouc  is  mixed  with 
varying  amounts  of  sulphur ;  for  soft  rubber  goods  with  about  ten  per  cent., 
for  hard  rubber  or  vulcanite  with  thirty  to  thirty-five  per  cent.,  of  sulphur. 
Instead  of  sulphur,  metallic  sulphides  are  used,  such  as  alkaline  sulphides, 
sulphide  of  lead,  and  sulphide  of  antimony.  For  red  rubber  goods  the 
latter  is  always  used.  For  soft  rubber  articles  the  proper  temperature  for 
vulcanization  lies  between  120°  and  136°  C.;  for  hard  rubber,  from  140° 
to  142°  C.  In  vulcanizing,  only  a  part  of  the  sulphur  is  chemically  com- 
bined, a  part  remaining  mechanically  mixed.  This  can  be  largely  removed 
by  boiling  the  finished  articles  in  a  solution  of  caustic  soda.  Both  air-baths 
and  steam-baths  are  in  use  for  heating,  the  latter  at  present  in  the  majority 
of  cases.  A  form  of  vulcanizing  vessel  for  smaller  articles  is  shown  in 
Fig.  37.  The  lid  can  be  removed  by  the  mechanism  shown  at  a,  and  the 
manometer  m  shows  the  pressure  existing  in  the  vulcanizer  A.  This  final 
heating  which  effects  the  change  in  the  rubber  is  frequently  called  the 
"  curing"  of  the  rubber.  Vulcanized  rubber  goods  can  be  manufactured  in 
the  greatest  variety  of  shapes  and  for  a  multitude  of  uses,  the  rubber  being 
in  almost  all  cases  "  cured"  after  the  shaping. 

In  the  manufacture  of  hard-rubber  articles,  the  East  Indian,  and  spe- 
cially the  Java  and  Borneo,  caoutchouc  is  used,  the  Para  rubber  being  too 
expensive,  and  besides  not  so  well  adapted.  While  in  the  manufacture 
of  soft  rubber,  the  burning  or  curing  was  the  last  process,  following  the 
shaping  of  the  articles,  in  the  manufacture  of  the  hard  rubber  the  curing  is 


PEOCESSES  OF  TREATMENT. 


107 


generally  done  before  the  articles  are  finally  shaped.  Only  in  the  manufac- 
ture of  moulded  goods  is  the  curing  done  last.  Gutta-percha,  balata,  and 
colophony  resin  are  often  added  to  modify  the  hardness  and  elasticity,  while 
a  large  number  of  mineral  substances,  such  as  chalk,  gypsum,  calcined  mag- 
nesia, zinc  oxide,  asphalt,  etc.,  are  added  chiefly  for  cheapening  purposes. 


FIG.  37. 


A  kind  of  vulcanite  or  hard  rubber  which  contains  a  very  large  proportion 
of  vermilion  is  used,  under  the  name  of  dental  rubber,  for  making  artificial 
gums. 

The  working  over  of  scrap  rubber  has  in  recent  years  assumed  much 
importance.  Although  scraps  of  raw  caoutchouc  can  easily  be  kneaded  or 
rolled  together,  vulcanized  rubber  cannot  be.  The  insolubility  of  the  vul- 
canized rubber  in  ordinary  solvents  presents  another  difficulty.  Although 
the  problem  is  not  yet  solved,  numerous  proposals  have  been  made.  These 
all  involve  one  of  three  lines  of  treatment :  (1)  mechanical  subdivision  of 
the  scrap  and  the  adding  of  the  powder  so  obtained  to  fresh  caoutchouc; 
(2)  heating  the  vulcanized  scrap  to  fusion  and  use  of  the  pitchy  mass  so 
obtained  as  mixing  material ;  (3)  partial  desulphurization  of  the  caoutchouc, 
solution  in  suitable  solvents,  driving  off  the  solvent,  and  use  of  the  residuum 
so  obtained. 

Treatment  of  Gutta-percha. — This  is  quite  similar  to  that  described 
under  caoutchouc.  The  crude  gutta-percha  must  be  thoroughly  washed 
and  freed  from  dirt  and  mechanically  mixed  impurities.  It  is  then  cut  or 
torn  into  fine  shreds,  which  are,  after  washing,  heated  so  as  to  ball  them 
together.  It  is  now  kneaded  and  compacted  so  as  to  drive  out  the  air- 
bubbles. 

Gutta-percha  is  used  both  in  the  vulcanized  and  unvulcanized  condition. 
The  vulcanization  is  carried  out,  as  in  the  case  of  caoutchouc,  by  the  addi- 
tion of  sulphur  and  curing.  The  amount  of  sulphur  varies  from  six  to 
ten  per  cent.,  and  the  temperature  for  vulcanization  lies  between  135°  and 


108          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND   RESINS. 

1 50°  C.  The  gntta-percha  scraps  are  worked  up  generally  by  desulphurizing 
the  vulcanized  material  by  boiling  for  five  to  six  hours  in  a  six  to  eight 
per  cent,  solution  of  caustic  soda,  washing,  drying,  dissolving  in  carbon 
disulphide,  benzene,  or  turpentine,  and  then  distilling  off  the  solvent. 


IE.  Products. 

1.  PERFUMES. — The  general  character  of  the  several  classes  of  perfumes 
has  already  been  indicated  in  the  previous  section,  while  the  products  are 
so  extremely  numerous  and  special  in  character  that  any  attempt  at  detailed 
description  would  be  beyond  the  province  of  this  work. 

2.  VARNISHES. — We  have  to  note  here   both  the  natural  varnishes, 
already  referred  to  (see  p.  100),  and  manufactured  varnishes.     The  classi- 
fication of  manufactured  varnishes,  already  given,  was:     (1)  Linseed-oil 
varnishes,  including  both  plain  boiled  linseed-oil  varnish  and  solutions  of 
resins  in  the  boiled  oil,  or  lacquers,  as  they  are  often  called ;  (2)  spirit 
varnishes,  including  not  only  alcoholic  solutions  of  resins,  but  solutions 
of  the  latter  in  benzol,  petroleum  spirit,  wood-naphtha,  and  other  volatile 
liquids,  and  (3)  turpentine-oil  varnishes. 

Natural  Varnishes. — With  regard  to  the  Burmese  and  Indian  lacquers, 
little  is  known  except  as  to  their  production  as  crude  materials.  The 
Japanese  lacquer  has  been  more  fully  described,  and  the  methods  of  ap- 
plying it  attentively  followed.  As  the  varnish  flows  from  the  incisions 
in  the  trees  of  the  Rhus  species  it  is  a  milky  juice,  which,  on  exposure, 
quickly  darkens  and  blackens  in  color.  After  resting  in  tubs  for  some 
time  the  juice  becomes  thick  and  viscous,  the  thicker  portions  settle  at  the 
bottom  of  the  vessel,  and  from  it  the  thinner  top  stratum  is  separated  by 
decanting.  Both  qualities  are  strained  to  free  them  from  impurities,  and 
when  ready  for  use  they  have  a  rich  brown-black  color,  which,  however, 
in  thin  layers  presents  a  yellow,  transparent  aspect.  This  varnish,  when 
applied  to  any  object,  becomes  exceedingly  hard  and  unalterable,  and  with 
it  as  a  basis  all  the  colored  lacquers  of  Japan  are  prepared.  The  black 
variety  of  the  lacquer  is  prepared  by  stirring  the  crude  varnish  for  a  day 
or  two  in  the  open  air,  by  which  it  becomes  a  deep  brownish-black. 
Towards  the  completion  of  the  process,  a  quantity  of  highly  ferruginous 
water,  or  of  an  infusion  of  gall-nuts  darkened  with  iron,  is  mixed  with  the 
varnish,  and  the  stirring  and  exposure  are  continued  till  the  added  water 
has  entirely  evaporated,  leaving  a  rich  jet-black  varnish  of  proper  consistency. 
In  preparing  the  fine  qualities  of  Japanese  lacquer,  the  material  receives 
numerous  coats,  and  between  each  coating  the  surface  is  carefully  ground 
and  smoothed.  The  final  coating  is  highly  polished  by  rubbing,  and  the 
manner  in  which  such  lacquered  work  is  finished  and  ornamented  presents 
endless  variations.  The  durability  of  Japanese  lacquer-work  is  such  that 
it  can  be  used  for  vessels  to  contain  hot  tea  and  other  food,  and  it  is  even 
unaffected  by  highly-heated  spirituous  liquors. 

Linseed-oil  Varnishes. — The  method  of  burning  linseed  or  similar  drying 
oil  in  order  to  develop  its  varnish-forming  character  has  been  described 
(see  p.  102).  The  use  of  metallic  oxides  and  salts  as  driers  has  also 
been  referred  to.  In  this  connection  an  additional  word  may  be  had.  While 
litharge  and  lead  acetate  are  commonly  used,  they  must  be  replaced  by 
manganese  or  other  driers  when  the  boiled  oil  is  to  be  used  as  the  basis  of  zinc 


PRODUCTS.  109 

oxide  paint.  Lately,  manganous  borate  has  been  strongly  recommended  as 
a  drier,  and  it  is  asserted  that  it  is  capable  of  giving  rapid  drying  qualities  to 
linseed  oil  when  it  is  heated  a  sufficient  length  of  time  (from  ten  to  fourteen 
days)  at  a  temperature  of  only  40°  C.  Such  a  boiled  oil  would,  of  course,  be 
lighter  in  color  than  if  treated  at  a  higher  temperature.  Liquid  driers  are 
also  in  use  at  present  which  have  the  advantage  of  acting  gradually  upon 
the  linseed  oil  without  the  aid  of  heat,  so  that  a  boiled  oil  of  very  light 
color  is  obtainable.  These  driers  contain  manganese  and  lead-Jinoleates 
and  resi nates,  and  concentrated  solutions  in  oil  or  turpentine  are  prepared 
for  addition  to  the  oil  to  be  oxidized.  Boiled  oil  is  often  bleached  by  sun- 
light, and  always  improves  by  keeping,  as  impurities  gradually  settle  out, 
and  its  drying  qualities  develop  by  age. 

The  most  important  of  the  linseed-oil  resin  varnishes  are :  Amber  var- 
nish, the  most  durable  and  resisting  oil  varnish,  but  unfortunately  of  dark 
color  ;  copal  varnish,  the  finest  of  all  the  oil  varnishes,  nearly  as  hard  and 
durable  as  amber  varnish,  much  paler  in  color,  and  drying  more  quickly  ; 
and  kauri  resin  and  colophony  resin  for  inferior  varnishes.  The  best  oil 
varnishes  are  made  from  "  fused"  copal  or  amber,  with  boiled  linseed  oil, 
subsequently  thinned  out  with  oil  of  turpentine. 

Spirit  varnishes  are  easily  obtained  perfectly  clear ;  they  dry  very 
rapidly,  and  leave  smooth,  lustrous  films,  which  appear  at  first  unexcep- 
tionable. But  slight  vibrations  and  changes  of  temperature  soon  develop 
innumerable  small  cracks,  in  consequence  of  which  it  loses  its  lustre,  and 
if  the  varnish  layer  was  thick  it  begins  to  peel  off.  The  reason  of  this  is 
that  the  film  consisted  simply  of  unaltered  resin,  spread  in  a  thin  layer, 
and  as  most  of  the  resins  are  brittle  by  nature,  slight  shocks  or  changes 
of  temperature,  inducing  contraction  or  expansion  of  the  article  varnished, 
will  cause  the  resin  film  to  break.  What  is  true  of  alcoholic  varnishes 
applies,  of  course,  also  to  all  varnishes  where  the  solvent  of  the  resin  takes 
no  part  in  the  formation  of  the  film.  The  more  volatile  the  solvent  the 
quicker  the"  film  is  deposited  and  the  easier  it  cracks.  Two  methods  of 
obviating  this  difficulty  are  in  use  :  first,  to  mix  with  the  brittle  resin  a  soft, 
balsam-like  resin,  and,  second,  to  mix  spirit  varnish  with  one  prepared  with 
turpentine  oil. 

Turpentine  varnishes  are  seldom  used  exclusively  as  such  because  of  the 
strong  and  persistent  turpentine  odor.  When  used  alone  they  give  films 
as  perfect  as  those  gotten  by  the  use  of  spirit  varnishes,  but  tougher  and 
drying  more  slowly  than  these  latter.  Usually,  however,  turpentine  oil 
is  used  in  connection  with  boiled  linseed  or  other  drying  oil  in  varnish 
manufacture,  as  in  the  case  given  of  copal  varnish,  before  described  (see 
p.  104).  The  resins  used  for  turpentine-oil  varnishes  are  the  varieties  of 
copal,  amber,  sandarach,  dammar,  mastic,  and  coniferous  resins. 

Japans  are  simply  varnishes  that  yield,  on  drying,  very  hard,  brilliant 
coatings  upon  paper,  wood,  or  metal,  analogous  to  the  natural  lacquer  of 
Japan,  before  described.  The  effecting  of  this  result  is  gotten  in  general 
by  exposing  the  articles  to  high  temperatures  in  stoves  or  hot  chambers 
subsequent  to  the  application  of  the  varnish.  This  supplementary  heating 
process  is  called  "japanning."  It  is  done  with  clear,  transparent  varnishes, 
in  black  and  in  colors,  but  black  japan  is  the  most  characteristic  and  com- 
mon style  of  work.  Black  japan  varnish  contains  asphaltum  as  the  basis, 
and  when  applied  in  several  layers,  each  of  which  is  separately  dried  in  the 
stove  at  a  heat  rising  to  300°  F.  (149°  C.),  is  susceptible  of  a  high  polish. 


110          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

Japanning  may  be  regarded  as  a  process  intermediate  between  ordinary 
painting  and  enamelling.  It  is  very  extensively  applied  in  the  finishing  of 
ordinary  hardware  goods  and  domestic  iron-work,  deed-boxes,  clock-dials, 
and  papier-mache"  articles.  The  process  is  also  applied  to  blocks  of  slate 
for  making  imitation  of  black  and  other  marbles  for  chimney-pieces,  etc., 
and  a  modified  form  of  japanning  is  employed  for  prepared  enamel,  japan, 
or  patent  leather. 

3.  PRINTING  INKS. — The   character  of  printing  inks  has  been  suffi- 
ciently indicated  in  the  description  of  its  manufacture.     (See  p.  104.) 

4.  MISCELLANEOUS  PRODUCTS  FROM  RESINS  AND  ESSENTIAL  OILS. 
— (1)  Sealing-wax  is   a  valuable   product    of  manufacture    from   shellac. 
Venice  turpentine  is  always  added  to  the  shellac  to  make  it  more  fusible 
and  less  brittle,  and  some  mineral  coloring  matter,  which,  in  the  case  of 
the  common  red  variety,  is  always  vermilion.      For  black  sealing-wax  the 
best  ivory-black  is  used,  for  golden-colored  wax,  "  mosaic  gold"  (stannic  sul- 
phide), for  green  wax,  powdered  verdigris.      For  the  commoner  varieties, 
earthy  materials,  like  chalk,  magnesia,  burnt  plaster,  barytes,  or  infusorial 
earth,  are  added  for  the  double  purpose  of  making  it  less  fusible  and  to 
weight  it.      Perfumed  sealing-waxes  are  scented  with  benzoin,  Peru  and 
Tolu  balsams,  and  storax.      As  a  substitute  for,  or  adulterant  of,  shellac 
in  the  manufacture  of  sealing-wax,  gum  acaroides  has  recently  come  into 
use. 

J2)  Rosin  Oil. — In  recent  years  great  importance  has  attached  to  the 
ucts  of  the  dry  distillation  of  common  colophony  resin  or  "  rosin."  It 
yields,  on  distillation,  two  valuable  products :  first,  from  three  to  seven  per 
cent,  of  a  light  fraction  known  as  rosin  spirit,  or  "  pinoline,"  and,  second, 
from  seventy  to  eighty-five  per  cent,  of  rosin  oil,  a  violet-blue  fluorescing 
liquid,  varying  in  specific  gravity  from  .98  to  1.1.  The  pinoline  is  used  as 
an  illuminant  and  as  a  substitute  for  turpentine  oil  in  varnish  manufacture. 
The  rosin  oil  has  a  large  use  as  a  lubricant,  especially  for  machinery  and 
wagon-wheels.  It  is  used  in  the  condition  of  "  rosin  grease"  (made  by 
stirring  rosin  oil  with  milk  of  lime),  and  largely  as  a  substitute  for  linseed  oil 
in  the  manufacture  .of  printer's  ink.  (See  p.  104.)  Moreover,  as  it  can  be 
deprived  of  its  fluorescence  or  "  bloom"  in  various  ways  (exposure  to  sun- 
light, treatment  with  hydrogen  peroxide,  nitro-benzene,  dinitro-naphtha- 
lene,  etc.),  it  can  be  used  in  adulterating  olive,  rape,  and  sperm  oils.  The 
best  mineral  lubricating  oils  are  also  adulterated  with  it  at  times. 

(3)  Oil-cloth  and  Linoleum. — The  general  outlines  of  the  manufacture 
of  these  products  as  given  on  page  105,  allow  one  to  form  an  idea  of  the 
character  of  them. 

Oil-cloth  is  a  firm  but  flexible  fabric,  which  by  its  treatment  has  been 
made  water-proof  and  impervious  to  atmospheric  influences.  It  can  be 
washed  and  cleansed,  and,  under  ordinary  wear,  retains  for  a  considerable 
time  its  lustre  and  brilliancy  of  printed  pattern.  It  is,  however,  cold  and 
hard,  and,  unless  well  seasoned,  the  pattern  is  liable  to  wear  off.  The 
covering  film  will  not  stand  much  bending  without  cracking,  and  then  it 
rapidly  disintegrates. 

Linoleum  is  softer  and  more  elastic  to  the  feet,  and,  if  the  composition 
has  been  properly  made,  shows  great  elasticity  and  toughness,  so  that  its 
wearing  powers  are  notably  greater  than  those  of  oil-cloth.  In  laying  down 
linoleum,  the  edges  may  be  cemented  to  the  floor  by  using  a  thick  solution 
of  shellac  in  methylated  spirit. 


PRODUCTS.  Ill 

(4)  Linseed-oil  Caoutchouc. — For  the  preparation  of  this  substitute  for 
caoutchouc,  linseed  oil  is  heated  to  a  high  temperature  for  a  considerable 
time  until  it  becomes  dark  and  has  changed  into  a  tough  mass.  It  is  stated 
that  when  vulcanized  by  the  acid  of  sulphur  chloride  it  can  be  used  as  a 
substitute  or  adulterant  of  genuine  caoutchouc. 

5.  INDIA-RUBBER  AND  GUTTA-PERCHA  PRODUCTS. — In  noting  the 
properties  of  crude  caoutchouc  it  was  stated  that  the  raw  caoutchouc,  while 
elastic  at  ordinary  temperatures,  did  not  show  the  same  character  when 
chilled,  as  it  became  hard,  and  when  heated  it  lost  the  elastic  feature  en- 
tirely. On  the  other  hand,  vulcanized  caoutchouc  or  manufactured  rubber 
shows  no  change  in  its  elasticity,  even  within  very  wide  limits  of  tempera- 
ture. Freshly-cut  surfaces,  on  being  pressed  together,  will  not  adhere  as 
was  the  case  with  raw  caoutchouc ;  it  swells  up  only  slightly  in  bisulphide 
of  carbon,  oil  of  turpentine,  and  other  solvents,  while  the  raw  caoutchouc 
swells  up  greatly  and  even  dissolves  in  part.  The  vulcanized  rubber  is 
much  more  impervious  to  water  than  the  raw  material.  As  stated  before, 
not  all  of  the  sulphur  present  in  the  vulcanized  rubber  is  chemically  com- 
bined. A  large  excess  of  uncombined  sulphur  is,  however,  deleterious  to 
the  goods,  as  it  causes  them  to  lose  their  elasticity  when  they  are  stored  for 
a  few  years.  If  such  goods  are  treated  with  alkaline  solutions,  the  free 
sulphur  can  be  removed  without  impairing  the  elastic  character  of  the  vul- 
canized caoutchouc.  Hard  rubber,  prepared,  as  described  before,  from 
crude  caoutchouc,  with  a  larger  percentage  of  sulphur,  has  a  black  color 
and  takes  a  high  degree  of  polish.  Articles  of  this  material  can  also  be 
gotten  of  any  desired  color,  as  in  the  case  of  the  dental  rubber  previously 
referred  to.  Besins,  like  shellac,  are  often  added  to  give  elasticity  to  the 
hard  rubber,  die  amount  of  resin  capable  of  being  taken  up  being  consider- 
able, equalling  at  times  fifty  per  cent,  of  the  combined  weight  of  the 
caoutchouc  and  sulphur.  Hard  rubber  becomes  strongly  electrified  by  rub- 
bing, and  hence  is  used  in  various  plate  electrical  machines,  while  its  non- 
conducting qualities  make  it  valuable  for  insulators  in  various  forms  of  tele- 
graphic apparatus.  Hard  rubber  is  unacted  upon  by  strong  mineral  acids 
and  other  chemicals,  and  hence  is  used  for  acid-pumps  and  connections,  for 
spatulas,  photographic  dishes,  etc. 

Rubber  substitute,  or  so-called  "artificial  rubber,"  is  made  by  acting 
upon  linseed,  rape,  poppy,  hemp,  and  cotton-seed  oils  with  sulphur  chloride, 
and  removing  the  hydrogen  chloride  formed  by  after-treatment  with  milk 
of  lime.  The  result  is  a  tough  rubber-like  mass,  which,  however,  becomes 
more  or  less  brittle  on  keeping. 

It  is  asserted  that  a  better  product  is  obtained  by  using  oxidized  or 
"blown"  oils  for  the  treatment  with  the  sulphur  chloride.  The  acid 
"  sludge"  from  the  refining  of  petroleum  is  also  converted  into  a  rubber 
substitute  by  heating  and  removal  of  the  free  acid. 

Gutta-percha,  in  the  pure  as  well  as  the  vulcanized  condition,  has  been 
adapted  to  a  multitude  of  uses.  One  of  the  most  important  uses  of  gutta- 
percha  is  as  a  material  for  the  matrices  or  moulds  for  coins,  medals,  smaller 
art  castings,  etc.,  and  all  forms  of  galvano-plastic  work.  The  pure  gutta- 
percha  serves  very  well  to  take  imprints,  but  for  overlaying  matrices  or 
moulds  compositions  of  gutta-percha  and  caoutchouc  must  be  used,  to  unite 
plasticity  when  heated  with  sufficient  elasticity  to  allow  of  the  matrix  being 
removed  without  injury  to  the  impression.  The  chief  use  for  gutta-percha, 
however,  is  for  telegraphic  cable  insulation  (every  nautical  mile  of  cable  re- 


112          INDUSTRY  OF  THE   ESSENTIAL   OILS   AND   EESINS. 

quiring  about  one-half  of  a  ton  of  gutta-percha),  and  the  chief  purchaser 
and  worker  in  gutta-percha,  therefore,  is  the  "  Telegraph  Construction  and 
Maintenance  Company/'  of  London,  who  buy  up  the  crude  gutta-percha 
through  their  agents  in  Singapore.  The  gutta-percha  is  covered  upon  the 
wires  by  pressing.  The  partly  vulcanized  and  warm  gutta-percha  mass  is 
forced  out  of  a  powerful  press  along  with  and  around  the  wire  or  wires  to 
be  covered.  The  gutta-percha  must  have  previously  been  well  kneaded  to 
remove  the  air  thoroughly  from  it,  so  that  it  may  pack  uniformly. 

Gutta-percha  is  also  incorporated  with  powdered  wood  and  sawdust, 
making  a  composition  Avhich  is  very  hard  and  can  be  worked  by  means  of 
the  saw  and  turning-lathe  into  a  variety  of  shapes. 


IV.  Analytical  Tests  and  Methods. 

1.  FOR  ESSENTIAL  OILS. — Essential  oils  are  extremely  liable  to  adul- 
teration, the  high  price  of  many  of  the  finer  ones  lending  to  this  tendency. 
The  usual  adulterations  are  with  alcohol,  chloroform,  oil  of  turpentine,  fixed 
oils,  both  vegetable  and  mineral,  and  spermaceti,  and  by  mixing  the  cheaper 
essential  oils  with  the  more  expensive.  In  addition  to  the  above  intentional 
adulterants,  volatile  oils  are  apt  to  contain  water  and  resinous  and  other 
oxygenated  bodies,  produced  by  their  exposure  to  air. 

The  detection  of  fatty  oils,  resins,  or  spermaceti  can  often  be  effected  by 
simply  placing  a  drop  of  a  suspected  oil  upon  a  piece  of  white  paper  and 
exposing  it  for  a  short  time  to  heat.  If  the  oil  is  pure  it  will  entirely 
evaporate ;  but  if  one  of  these  adulterants  be  present,  a  greasy  or  translu- 
cent stain  will  be  left  on  the  paper.  These  substances  will  also  remain 
nndissolved  when  the  oil  is  agitated  with  thrice  its  volume  of  rectified 
spirit. 

Alcohol  in  essential  oils  may  be  detected  by  agitating  the  oil  with  small 
pieces  of  dry  calcium  chloride.  These  remain  unaltered  in  a  pure  essential 
•oil,  but  dissolve  in  one  containing  alcohol,  and  the  resulting  solution  sepa- 
rates, forming  a  distinct  stratum  at  the  bottom  of  the  vessel.  When  only  a 
very  little  alcohol  is  present,  the  pieces  merely  change  their  form  and  exhibit 
the  action  of  the  solvent  on  their  angles  or  edges,  which  become  more  or 
less  obtuse  or  rounded.  If  the  experiment  be  performed  in  a  graduated 
tube  and  a  known  measure  of  the  oil  employed,  the  diminution  in  its  vol- 
ume will  give  that  of  the  alcohol  mixed  with  it.  Dragendorff  recommends 
the  use  of  metallic  sodium,  which  does  not  act  on  hydrocarbons,  and  but 
slightly  in  the  cold  on  oxygenated  essential  oils  if  pure  and  dry,  but  in  the 
presence  of  ten  or  even  five  per  cent,  of  alcohol  a  small  piece  of  the  sodium 
is  dissolved,  while  a  brisk  evolution  of  gas  takes  place.  Aniline-red  (ma- 
genta) is  insoluble  in  essential  oils  if  pure  and  dry,  but  in  the  presence  of 
a  small  proportion  of  alcohol  they  acquire  a  pink  or  red  color.  This  adul- 
teration with  alcohol  is  said  to  be  very  common,  as  it  is  a  frequent  practice 
of  druggists  to  add  a  little  of  the  strongest  rectified  spirit  to  their  essential 
oils  to  render  them  transparent,  especially  in  cold  weather.  Oil  of  cassia 
is  a  notable  example  of  an  oil  treated  in  this  way. 

The  adulteration  of  essential  oils  with  fixed  oils  is  best  distinguished  by 
what  is  termed  "  steam  distillation."  The  essential  oils  all  distil  over  with 
steam  at  100°  C.,  while  resinous  matters  and  fixed  oils,  added  as  adulterants, 
ivill  remain  in  the  retort.  The  adulteration  of -the  finer  essential  oils  with 


ANALYTICAL   TESTS   AND   METHODS. 


113 


cheaper  essential  oils  is  constantly  met  with.  Thus,  the  expensive  oil  of 
cassia  is  adulterated  with  oil  of  cedarwood  ;  oil  of  rose  with  oil  of  geranium  ; 
and  oil  of  geranium  with  oil  of  turpentine.  Noting  the  specific  gravity 
carefully  where  that  is  characteristic,  and  noting  the  odor  on  evaporating,  are 
methods  most  generally  resorted  to  for  the  detection  of  these  fraudulent 
admixtures.  The  adulteration  of  essential  oils  with  oil  of  turpentine  is, 
unfortunately,  one  of  those  difficult  of  detection,  and  no  method  of  testing 
has  as  yet  been  suggested  that  will  always  show  it. 

The  determination  of  the  saponification  equivalent  has  been-shown  to 
be  of  importance  in  such  oils  as  contain  esters,  like  bornyl  acetate,  etc. 
As  some  oils  contain  free  alcohols,  the  determination  of  the  acetyl  figure 
is  also  of  importance  as  a  test  for  purity.  Benedikt  and  Griessner  also 
recommend  the  determination  of  the  methyl  figure  in  such  cases  as  the 
analysis  of  oil  of  cloves,  anise,  or  fennel. 

The  essential  oils  give  a  variety  of  color-tests  with  such  reagents  as  con- 
centrated sulphuric  acid,  fuming  nitric  acid,  bromine,  picric  acid,  etc.,  which, 
however,  are  not  sufficiently  characteristic  to  allow  of  their  being  used  to 
recognize  adulterations.  The  purity  of  oil  of  turpentine,  as  commercially 
the  most  important  of  the  essential  oils,  is  often  a  question  to  be  deter- 
mined. The  most  usual  adulterants  of  oil  of  turpentine  are  light  petro- 
leum-naphtha, known  as  "  turpentine  substitute,"  "  rosin  spirit,"  and  of  late 
a  so-called  "  light  camphor  oil,"  gotten  as  a  side-product  in  the  manufacture 
of  safrol.  The  following  tabular  statement  of  Allen  *  shows  the  characters 
of  oil  of  turpentine,  rosin  spirit,  and  petroleum-naphtha  under  the  influence 
of  different  reagents : 


Turpentine  oil. 

Rosin  spirit. 

Petroleum-naphtha. 

1.  Optical  activity  .  .  . 

Active. 

Usually  none. 

None. 

2.  Specific  gravity  .   .    • 

.860  to  .872. 

.856  to  .880. 

.700  to  .740. 

3.  Temperature  of  dis- 

156° to  180°. 

Gradual  rise. 

Gradual  rise. 

tillation,  C.  °. 

4.  Action    in  the   cold 
on  coal-tar  pitch. 

Readily  dissolves  pitch 
to  a  deep-brown  solu- 

Readily dissolves  pitch 
to  a  deep-brown  solu- 

Very slight  action,  lit- 
tle or  no  color. 

tion. 

tion. 

5.  Behavior  with  abso- 

Homogeneous     m  i  x- 

Homogeneous      m  i  x- 

No  apparent  solution. 

lute    phenol,   3    of 

ture. 

ture. 

sample  to  1  of  phe- 

nol, at  20°  C. 

6.  Behavior   on    shak- 
ing 3  parts  of  cold 
sample  with  1  part 

Homogeneous      m  i  x- 
ture. 

Homogeneous     m  i  x- 
ture. 

Liquid   separates  into 
two  layers  of  nearly 
equal  volume. 

castor  oil. 

7.  Bromine  absorption. 

203  to  236. 

184  to  203. 

10  to  20. 

8.  Behavior    with   sul- 

Almost completely 

Polymerized. 

Very  little  action. 

phuric  acid. 

polymerized. 

It  will  be  seen  that  the  presence  of  petroleum  spirit  can  be  indicated 
by  almost  all  of  these  reagents,  while  that  of  rosin  spirit  would  hardly  be 
shown.  H.  E.  Armstrong  f  recommends  a  process  which  consists  of  agi- 
tating the  suspected  turpentine  sample  first  with  sulphuric  acid  and  water 
(2:1),  carefully  avoiding  too  high  a  rise  of  temperature.  This  gradually 
polymerizes  the  genuine  oil  of  turpentine,  changing  it  to  a  viscid  non- 
volatile oil.  The  sample  is  then  distilled  with  steam,  and  that  which  is 
volatile  at  this  temperature  is  now  treated  with  4:1  sulphuric  acid  and 
water.  The  polymerization  of  the  turpentine  is  usually  completed  by  this 

*  Allen,  Commercial  Org.  Anal.,  2d  ed.,  ii.  p.  439. 
f  Journ.  Soc.  Chem.  Ind.,  i.  p.  480. 
8 


114          INDUSTKY  OF  THE   ESSENTIAL   OILS  AND   EESINS. 

treatment,  while  any  petroleum-naphtha  present  is  not  affected,  and  remains 
as  volatile  as  before.  A  final  steam  distillation  will  give  the  petroleum- 
naphtha  originally  present  in  the  turpentine  sample.  Rosin  spirit  is  partly 
polymerized  in  this  treatment,  while  volatile  hydro-carbons  remain,  but  its 
presence  is  much  harder  to  indicate  certainly  than  that  of  petroleum. 

Dunwoody  has  shown  that  mixtures  of  turpentine  and  petroleum  are 
much  less  soluble  in  ninety-nine  per  cent,  acetic  acid  than  pure  turpentine. 
While  ten  cubic  centimetres  of  pure  turpentine  are  soluble  in  an  equal 
volume  of  a  mixture  of  ninety-nine  parts  glacial  acetic  acid  and  one  part 
water,  it  requires  forty  cubic  centimetres  of  such  mixture  when  the  turpen- 
tine contains  ten  per  cent,  of  petroleum,  sixty  cubic  centimetres  if  twenty 
per  cent,  of  petroleum  be  present,  and  so  on  in  increasing  rates. 

The  Prussian  custom  regulations  prescribe  a  similar  test  with  aniline 
oil.  Ten  cubic  centimetres  of  the  sample  are  shaken  tip  in  a  stoppered 
jar  with  ten  cubic  centimetres  of  aniline  oil.  If  pure  turpentine  is  used,  a 
clear  solution  follows ;  if  petroleum  is  present,  two  layers  are  formed. 

The  oxidizing  effect  of  fuming  nitric  acid  is  also  availed  of  to  detect 
the  presence  of  mineral  oil  in  turpentine,  as  the  latter  is  entirely  oxidized, 
while  the  former  is  not  affected.  It  is  stated  that  this  test  is  perfectly 
accurate  with  the  higher  boiling  fractions  of  petroleum,  but  that  the  lighter 
fractions  are  slightly  attacked. 

The  bromine  absorption  of  oil  of  turpentine  (see  p.  81)  is  higher  than 
that  of  any  of  these  adulterants,  and  that  may  in  many  cases  serve  to  indi- 
cate its  purity. 

The  iodine  absorption  percentages  with  HubFs  reagent  (see  p.  82)  for 
a  large  number  of  essential  oils  have  been  determined  by  R.  H.  Davies,* 
who  finds  that  the  differences  in  absorption  power  are  very  much  greater  in 
the  case  of  essential  than  in  that  of  fixed  oils.  Some  volatile  oils  do  not 
absorb  any  appreciable  amount  of  iodine,  while  others  will  remove  from 
solution  four  times  their  weight,  or  four  hundred  per  cent.  Thus,  oil  of 
turpentine  shows  an  absorption  equivalent  of  three  hundred  and  seventy- 
seven  per  cent. 

2.  FOR  RESINS. — The  tests  for  resins  or  resin  acids,  when  admixed 
with  fats  or  fatty  oils,  have  been  referred  to  under  the  discussion  of  the 
latter.  (See  p.  83.) 

From  admixture  with  the  neutral  fixed  oils  resins  may  be  separated 
by  treating  the  mixture  with  alcohol  of  about  .85  specific  gravity.  The 
alcohol  is  subsequently  separated,  and  the  dissolved  resin  recovered  by 
evaporating  it  to  dryness.  Acid  resins,  such  as  common  colophony,  may  be 
separated  from  the  neutral  fats  by  boiling  the  substance  with  a  strong  solu- 
tion of  sodium  bicarbonate  or  borax.  After  cooling,  the  aqueous  liquid  is 
separated  from  the  oil  and  the  resin  precipitated  from  its  solution  in  the 
sodium  salt  by  adding  hydrochloric  acid. 

Resins  may  be  separated  from  the  essential  oils  and  camphors  in  admix- 
ture with  which  they  so  frequently  occur  by  distilling  in  a  current  of  steam. 

The  resins  show  some  considerable  differences  when  examined  by  the  two 
methods  of  bromine  absorption  and  saponification  equivalent,  before  referred 
to  under  the  fatty  oils.  (See  p.  81.)  Mills  and  Muter  f  have  determined 
the  bromine  absorptions,  and  E.  J.  Mills  J  the  proportions  of  potash  neu- 

*  Phar.  Journ.  and  Trans.,  April,  1889,  p.  821,  and  Amer.  Journ.  of  Phar.,  1889,  p.  301. 
t  Journ.  Soc.  Chem.  Ind.,  iv.  p.  97.  J  Ibid.,  v.  221. 


ANALYTICAL   TESTS   AND   METHODS. 


115 


tralized  by  various  resins.     The  following  table  gives  a  summary  of  their 
results : 


KIND  OF  RESIN. 

KOH  neutralized 
per  cent. 

Saponification 
equivalent. 

Bromine  absorp- 
tion. 

Hydrobromic 
acid  formed. 

Kosin  (refined)  .... 
Shellac         

18.1 
23.0 

308.6 
242.7 

112.7 
5.2 

.    .    . 

Shellac  (bleached)    .    . 
Benzoin   

18.2 
223 

306.9 
256.0 

4.6 
38.9 

~8ome. 

16.1 

347.6 

53.5 

Some. 

Anime 

9  5 

5855 

60.2 

Much. 

Gamboge            . 

15.5 

361.1 

71.6 

Much. 

Copal                          .    . 

12.4 

450.8 

89.9 

Much. 

Copal  (reduced  to  £  by 
boiling)        

12.9 

433.4 

84.5 

Much. 

Sandarach   

16.4 

340.6 

96.4 

Very  much. 

Kauri 

12  9 

433  4 

108.2 

Thus 

21  0 

340.6 

108.6 

Dammar                      . 

52 

1068  1 

117.9 

Much. 

Elemi 

3  3 

1697.9 

122.2 

Very  much. 

Mastic             

11  7 

4786 

124.3 

Much. 

The  chief  feature  attracting  attention  is  the  low  bromine-absorption 
figure  gotten  with  shellac.  Mills's  method  could  probably  be  used  to  ad- 
vantage for  the  analysis  of  varnishes  after  evaporating  off  the  volatile  solvent. 

Hirschsohn  *  has  elaborated  a  systematic  scheme  for  the  identification  of 
resins,  gum-resins,  and  balsams  analogous  to  the  schemes  for  plant  analysis, 
in  which  he  uses  a  succession  of  solvents  and  reagents.  It  is  too  lengthy  to 
be  given  here  in  detail.  The  constantly-widening  use  of  rosin  oil  makes  the 
tests  for  its  presence  of  considerable  importance.  Rosin  oil  gives  a  character- 
istic violet  color,  with  anhydrous  stannic  chloride  or  bromide.  If  it  is- 
mixed  with  fatty  oils,  A.  H.  Allen  points  out  that  the  test  may  still  be  suc- 
cessfully applied  by  distilling  the  mixture  and  applying  the  test  to  the  first 
fraction  which  passes  over. 

Demski  and  Morawski  f  recommend  the  use  of  acetone  for  the  detection 
and  rough  determination  of  rosin  oil  in  mineral  oils.  According  to  these 
chemists,  rosin  oils  are  miscible  with  acetone  in  all  proportions,  while 
mineral  oils  require  several  times  their  volume  of  acetone  to  effect  solution. 
The  test  is  applied  by  agitating  fifty  cubic  centimetres  of  the  sample  with 
twenty-five  cubic  centimetres  of  acetone.  If,  on  allowing  the  mixture  to 
stand,  it  separates  into  two  layers,  ten  cubic  centimetres  of  the  upper  or 
acetonic  layer  should  be  removed  with  a  pipette  and  evaporated,  and  the 
residual  oil  weighed.  In  the  case  of  pure  American  or  Galician  lubricating 
oil  the  residue  will  weigh  about  two  grammes,  but  only  half  this  quantity 
will  be  obtained  from  Wallachian  or  Caucasian  oil.  It  is  stated  that  mix- 
tures of  rosin  oil  with  the  lubricating  oils  from  American  and  Galician 
petroleum  are  permanently  soluble  in  half  their  volume  of  acetone,  if  the 
proportion  of  rosin  oil  exceeds  thirty-five  per  cent,  of  the  mixed  oil,  but 
that  complete  solution  is  not  effected  in  the  case  of  Wallachian  and  Caucasian 
oils  unless  the  rosin  oil  constitutes  at  least  fifty  per  cent,  of  the  mixture. 
Ragosine  cylinder  oil  requires  an  addition  of  rosin  oil  equal  to  fifty-three 
per  cent,  of  the  mixture  to  become  soluble  in  half  its  volume  of  acetone. 


Watts 's  Diet,  of  Chem.,  viii.  p.  1743. 
Ding.  Polytech.  Journ.,  cclviii.  p.  82. 


116  INDUSTKY  OF  THE   ESSENTIAL   OILS   AND   RESINS. 

3.  FOR  VARNISHES. — The  most  important  constituent  which  enters 
into  the  manufacture  of  varnishes  is  undoubtedly  the  linseed  or  other  drying 
oil.     Linseed  oil  (see   p.    49)  is  liable  to  be  adulterated  with  other  vege- 
table oils,  with  fish  oils,  with  mineral  and  rosin  oils,  and  with  rosin  itself. 
As  mineral  and  foreign  seed  oils  are  lighter  in  specific  gravity  than  linseed 
oil,  while  rosin  and  rosin  oil  are  much  heavier,  by  the  judicious  use  of  a 
suitable  mixture  of  mineral  and  rosin  oils  extensive  adulteration  can  be 
effected  without  alteration  of  the  density.     The  analysis  of  a  linseed  oil  sup- 
posed to  be  adulterated  would  be  made  according  to  the  scheme  given  be- 
fore (see  p.  84)  for  the  analysis  of  a  fatty  oil  containing  foreign  admixtures. 
A.  H.  Allen  gives  also  a  rather  elaborate  method,  which  he  states  is  better 
adapted  for  a  boiled  linseed  oil,  for  the  details  of  which  the  reader  is  referred 
to  Allen's  "  Commercial  Organic  Analysis/'  3d  ed.,  vol.  ii.,  Part  ii.,  p.  155. 

4.  FOR   CAOUTCHOUC    AND   GUTTA-PERCHA. — The   adulterations  of 
caoutchouc  are  both  mineral,  or  inorganic,  and  organic  in  character.     A 
careful  incineration  of  a  given  specimen  in  a  porcelain  crucible  will  leave 
any  mineral  admixture,  as  ash.    Oxide  of  zinc,  gypsum,  and  such  admixtures 
are  thus  recognized.     To  determine  the  amount  of  sulphur,  the  specimen  is 
burned  in  a  current  of  oxygen,  the  gaseous  products  of  combustion  passed 
through  water  acidulated  with  nitric  acid,  so  that  the  sulphurous  acid  re- 
tained is  changed  into  sulphuric  acid,  which  is  then  determined  by  chloride 
of  barium  in  the  usual  way.    If  the  mass  contain  metallic  sulphide,  this  pro- 
cedure does  not  answer.     The  mass  must  be  deflagrated  in  a  crucible  with 
saltpetre  and  acid,  then  the  sulphur  determined  in  the  sulphate  of  potassium 
produced. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY, 

1874. — Gums,  Resins,  Oleo-resins,  etc.,  of  India,  M.  C.  Cooke,  London. 

Complete  Practical  Treatise  on  Perfumery,  A.  J.  Cooley,  Philadelphia. 
1875. — Notice  sur  la  Fabrication  et  PEmploi  du  Caoutchouc,  L.  Ogier,  Paris. 

Rohmaterialen  fur  Lack  und  Firniss  Fabrikation,  L.  E.  Andes,  Wien. 
1876. — Lehrbuch  der  Lackierkunst,  Creuzburg,  bearbeitet  von  Poppinghausen,  "Weimar. 
1877. — Die  Fabrikation  der  Aetherische  Oele,  Askinson,  Wien. 

Perfumery  and  Kindred  Arts,  Christiani,  Philadelphia. 
1879.— The  Art  of  Perfumery,  S.  Piesse,  London. 

Pharmacographia,Fluckiger  and  Hanbury,  2d  ed.,  London. 

Die  Kautchuk  Industrie,  F.  Clouth,  Weimar. 
1880. — Die  Fabrikation  des  Wachstuches,  R.  Esslinger,  Leipzig. 

Kautchuk  und  Gutta-percha,  R.  Hoifer,  Leipzig. 
1882. — Handbuch  der  Oelmalerei,  Bouvier,  Braunschweig. 
1883. — Die  Rohstoffe  des  Pflanzenreiches,  J.  Wiesner,  Leipzig. 

Caoutchouc  and  Gutta-percha,  Hoffer,  Philadelphia  and  London. 

Die  Fabrikation  der  Kaoutchuk  und  Gutta-percha  Waaren,  Heinzerling,  Braun- 
schweig. 

Painting  and  Painter's  Materials,  Condit  and  Scheller,  New  York. 
1884. — Handbuch  fur  Anstreicher  und  Lackirer,  L.  E.  Andes,  Leipzig. 

Die  Pflanzenstoife,  Huseman  und  Hilger,  2nd  Auf.,  Berlin. 
1885. — Die  Fabrikation  der  Siegel-  und  Flaschenlacke,  L.  E.  Andes,  Leipzig. 

Chemische  Reactionen  zum  Nachweise  des  Terpentinols,  H.  Hager,  Berlin. 
1887. — India-Rubber  and  Gutta-percha  and  their  Cultivation,  R.  Ferguson,  Colombo. 
1888. — Pharmaceutische  Chemie,  Fliickiger,  2te  Auf.,  Berlin. 
1890. — Fabrikation  der  Lacke  und  Firnisse,  P.  Lohmann,  Berlin. 

Practical  Treatise  on  the  Raw  Material  and  Manufacture  of  Rubber,  G.  N.  Nesien- 
son,  New  York. 

Treatise  on  the  Manufacture  of  Perfumes,  etc.,  J.  H.  Snively,  New  York. 
1891. — Rubber  Hand-Stamps  and  Manipulation  of  Rubber,  J.  O  C.  Sloane,  New  York. 

Die  Fliictigen  Oele  des  Pflanzenreich's,  G.  Bornemann,  Weimar. 


BIBLIOGRAPHY   AND   STATISTICS.  117 

1891.—  Fossil  Eesins,  Lawn  and  Booth,  New  York. 

Handbuch  der  Parfiimerie  und  Toilettenseifen,  C.  Deite,  Berlin. 

The  Art  of  Perfumery,  C.  H.  Piesse,  5th  ed.,  London. 
1892. — Practical  Treatise  on  Manufacture  of  Perfumery,  W.  T.  Brannt,  Philadelphia. 

Odorographia :  A  Natural  History  of  Perfume  Drugs,  J.  Ch.  Sawer,  London. 

Le  Caoutchouc  et  la  Gutta-percha,  E.  Chapel,  Paris. 

Perfumes  and  their  Preparation,  G=  W.  Askinson,  J.  Furst,  trans.  Spon,  London 
and  New  York. 

The  Chemistry  of  Paints  and  Painting,  A.  H.  Church,  2d  ed.,  London. 

The  Manufacture  of  Volatile  and  Fat  Varnishes,  Lacquers,  Siccatives,  and  Sealing 

Waxes,  E.  Andres,  translated  hy  W.  T.  Brannt,  Philadelphia.  -^ ^ 

1893. — Fabrication  des  Essences  et  des  Parfums,  P.  Durvelle,  Paris. 

Le  Caoutchouc  et  la  Gutta-percha,  R.  Bobet,  Paris. 

Pigments,  Paints,  and  Painting,  G.  Terry,  London. 

Varnishes,  Lacquers,  Printing  Inks,  etc.,  W.  T.  Brannt,  Philadelphia. 

The  Practical  Polish  and  Varnishmaker,  H.  C,  Standage,  London. 

Fabrication  des  Vernis,  L.  Naudin,  Paris. 
1894.— Descriptive  Catalogue  of  Essential  Oils,  etc.,  F.  B.  Power,  New  York. 

Das  Harz  der  Nadelhdlzer,  H.  Mayr,  Berlin. 

Die  Riechstoffe  und  ihre  Verwendung,  St.  Nicrozwiski,  7th  Auf.,  "Weimar. 

Odorographia,  Second  Series,  J.  Ch.  Sawer,  London. 
1895. — Couleurs  et  Vernis,  G.  Halphen,  Paris. 

Leinoel  und  Leinoel  Firniss,  H.  Amsel,  Zurich. 

Die  Fabrikation  der  Copal,  Turpentinol,  und  Spiritus  Lacke,  L.  E.  Andes,  2te  Auf., 

Wien. 
1896. — Oils  and  Varnishes,  Jas.  Cameron,  3d  ed.,  London. 

Die  Harze  und  ihre  Producte,  G.  Thenius,  Wien. 

Painter's  Colours,  Oils,  and  Varnishes,  G.  H.  Hurst,  2d  ed.,  London. 
1897. — Linseed  Oil  Manufacture  and  Varnishes,  John  Bannon,  New  York  and  Chicago. 
1898. — Essai  des  Huiles  Essentielles,  H.  Labbi,  Paris. 

Chemistry  of  Essential  Oils  and  Artificial  Perfumes,  E.  J.  Parry,  London. 
1899. — Die  Aetherischen  Oele,  Gildemeister  und  Hoffmann,  Berlin. 

Die  Gutta-percha,  Dr.  Eugen  Obach,  Dresden,  Blasewitz. 

Les  Huiles  Essentielles,  etc.,  Charalot,  Dupont  et  Pillet,  Paris. 

Manufacture  of  Varnishes,  A.  Livache,  translated  by  J.  G.  Mclntosh,  London. 
1900. — Analyse  der  Harze,  Balsame,  etc.,  K.  Dieterich,  Berlin. 

India-rubber,  Gutta-percha,  and  Balata,  W.  T.  Brannt,  Philadelphia. 

The  Chemistry  of  Essential  Oils  and  Artificial  Perfumes,  E.  J.  Parry,  London  and 
New  York. 

STATISTICS. 

No  attempt  will  be  made  to  take  up  the  essential  oils  in  detail.  The 
statistics  of  the  entire  class  will  be  given,  and  only  a  few  of  the  more 
important  substances  will  be  specially  mentioned. 

Essential  Oils. — The  export  of  essential  oils  (bergamot,  lemon,  etc.)  from 
Sicily  and  Calabria  in  recent  years  has  been : 

Kilos.  Value  in  lire  =  0.19&. 

1895 554,191  8,081,870 

1896 514,067  7,579,424 

1897 732,092  9,719,133 

1898 667,293  9,015,083 

1899 797,145  10,722,445 

Peppermint  oil  is  exported  from  Japan  in  three  forms :  as  dementhol- 
ized  oil,  as  mixed  oil  containing  about  forty  per  cent,  of  menthol,  and  as 
menthol  crystals.  The  statements  of  production,  therefore,  include  all 
three  of  these  sources. 

The  yield  and  stock  on  hand  of  Japanese  peppermint  oil  in  recent  years 
is  given  as  follows  by  Schimmel  &  Co. 

1896 .  223, 300  catties  (298, 664  Ibs.) 

1897 140,000   "   (187,250  "  ) 

1898 100,000   "   (133,750  "  ) 

1899 102,000   "   (136,425  "  ) 


118 


INDUSTKY  OF  THE   ESSENTIAL   OILS   AND   EESINS. 


The  American  production  of  peppermint  oil  for  1897  rose  to  251,000 
pounds.  The  production  for  1898  continued  about  the  same,  but  in  1899 
it  fell  to  180,000  pounds. 

An  estimate  of  the  world's  production  of  peppermint  oil  in  1899  was 
175,000  kilos.,  of  which  America  furnished  90,000  kilos,  and  Japan  70,000 
kilos. 

The  exports  of  cinnamon  chips,  for  the  extraction  of  oil  of  cinnamon, 
from  Ceylon  for  the  last  five  years  have  been  : 


1895 920,136  pounds. 

1896 808,502       " 

1897 1,067,051       " 


1898 1,414, 165  pounds. 

1899 1,829,127       " 


The  total  exports  of  chips  average  about  one-half  by  weight  of  the 
total  exports  of  Ceylon  cinnamon  bark.  The  world's  consumption  of  bark 
and  chips  together  during  the  last  few  years  has  been  in  round  numbers 
3,500,000  pounds  a  year. 

The  exports  of  citronella  oil  from  Ceylon  (Colombo  and  Galle)  have 
been  as  follows  for  the  past  five  years : 


1895 1,1 82, 255  pounds. 

1896 1,132,141       " 

1897    ......  1,182,867       " 


1898 1,365,917  pounds. 

1899 1,478,756       « 


The  production  of  spirit  of  turpentine  in  the  United  States  amounts 
at  present  to  about  25,000,000  gallons,  of  a  value  of  about  $8,500,000. 

The  exportations  of  turpentine  spirit  from  the  United  States  during 
the  last  five  years  were : 


Gallons    .    . 
Valued  at 


1895. 

14,652,738 
$3,998,277 


1896. 

17,431,566 
$4,613,811 


1897. 

17,302,823 
$4,447,551 


18,351,140 
$5,380,806 


17,760,533 
$6,100,419 


The  British  importations  of  turpentine  during  the  same  years  have 
been : 

1895.        1896.        1897.        1898.        1899. 

Hundredweight.     503,683          498,791          502,790          573,087          495,808 
Valued  at    .    .  £520,065       £490,381       £516,887       £652,740       £809,906 

Germany  and  Belgium  each  import  from  a  quarter  to  a  third  as  much 
turpentine  spirit  as  the  United  Kingdom. 

Camphor. — The  exportations  of  camphor  from  Japan  during  recent 
years  have  fallen  off  considerably.  They  were  for  1897, 1,552,000  pounds, 
and  for  1898,  1,448,000  pounds.  Considerable  additional  quantities  are 
exported  from  Formosa,  besides  the  Chinese  exportation,  for  which  no 
figures  are  attainable. 

The  quantities  imported  into  the  United  States  for  the  last  five  years 
have  been : 

1895.        1896.        1897.        1898.        1899. 

Pounds  .    .    .    .1,500,739        945,629       1,469,601       2,047,234       1,807,889 
Valued  at.    .    $284,968       $328,457         $332,748         $365,652         $322,100 

Resins. — The  exportations  of  rosin  (colophony  resin)  from  the  United 
States  for  the  last  five  years  have  been  as  follows  : 

1895.        1896.       1897.        1898.       1899. 

Barrels.    .    .    .    1,862,394       2,172,991       2,429,116       2,206,203       2,563,229 
Valued  at   .  $3,351,250     $4,151,748     $4,688,163     $3,689,252     $3,741,581 


BIBLIOGRAPHY  AND   STATISTICS.  119 

The  English  importations  of  rosin  for  the  last  three  years  were :  for 
1897,  1,640,745  hundredweight,  valued  at  £407,771  ;  for  1898,  1,662,279 
hundredweight,  valued  at  £361,169  ;  for  1899,  1,708,630  hundredweight, 
valued  at  £399,556. 

The  importations  of  shellac  for  the  last  five  years  to  the  United  States 
have  been  as  follows : 

1895.        1896.        1897.        1898.        1899. 

Pounds  ....    6,401,060      6,056,957       7,151,459     6,984,395      9,830,111 
Valued  at  .    .  $1,288,501     $1,210,802     $1,082,401      $939,361     $1,397^35 

The  English  importations  during  the  same  period  were : 

1895.        1896.        1897.        1898.        1899. 

Hundredweight  .     114,122          157,352         177,557  96,678         108,757 

Valued  at    .    .  £629,459       £776,117      £751,099       £333,326       £372,585 

The  exportations  of  kauri  (dammar)  resin  from  New  Zealand  within 
recent  years  have  been  as  follows : 

1888 .8,482  tons,  valued  at  £380,933 

1889 7,519  '       "     329,590 

1890 7,438  '        "     378,563 

1891 8,388  '        "     437,056 

1892 8,705  '        «     517,678 

1893 8,317  <       "     510,775 

An  estimate  of  the  present  annual  production  of  caoutchouc  throughout 
the  world,  which  appeared  in  the  Monthly  Bulletin  of  the  Bureau  of  the 
American  Republics,  is  as  follows  : 

Brazil  and  Peru  (yield  of  Para  rubber) 45,000,000  pounds. 

Brazil  (yield  of  Ceara  rubber) 9,400,000  " 

Brazil  (yield  of  Mangabeira  rubber) 6,500,000  " 

Guiana 600,000  " 

Bolivia 3,000,000  " 

Kest  of  South  America 4,000,000  " 

Total  for  South  America   .    .    .  68,500,000  pounds. 

Central  America  and  Mexico 5,000,000  " 

Java,  Borneo,  and  Malayan  Islands 2,000,000  " 

East  and  "West  Africa 48,000,000  " 

Madagascar  and  Mauritius 1,000,000  " 

India  and  Burmah 800,000  " 

Ceylon 15,000  " 


Total  world's  production 125,315,000       " 

Of  this  amount,  the  United  States  and  Canada  use  40,000,000  pounds, 
Great  Britain  and  colonies  (Canada  excepted),  45,000,000,  and  the  conti- 
nent of  Europe,  40,000,000  pounds. 

Gutta-percha. — The  entire  world's  production  of  gutta-percha  in  1890 
was  estimated  at  4,500,000  kilos.  This  amount  has  decreased  notably 
since  1890,  amounting  in  1896  to  only  2,600,000  kilos. 

The  United  States  importations  of  crude  caoutchouc  and  gutta-percha 
for  the  last  five  years  have  been  : 

1895.  1896.  1897.  1898.  1899. 

Caoutchouc  (Ibs.)    .    39,741,607  36,774,460  35,574,449  46,055,497  51,063,066 

Valued  at.    .    .    .$18,353,121  $16,603,020  $17,457,976  $25,386,010  $31,707,630 

Gutta-percha  (Ibs.)       1,326,794  3,843,854  1,117,665  636,477  518,939 

Valued  at.    .    .    ,       $122,261  $178,513  $100,187  $159,381  $167,577 


120          INDUSTRY  OF  THE   ESSENTIAL   OILS   AND   EESINS. 

The  English  importations  of  caoutchouc  and  gutta-percha  have  been 
for  the  same  period  : 

1895.  1896.  1897.  1898.                    1899. 

Caoutchouc  (cwt.)  .          341,553  431,164  396,929  489,601           449,647 

Valued  at.    .    .    .    £3,760.178  £4,993,186  £4,553,416  £6,215,183  £5,925,643 

Gutta-percha  (cwt.)          48,077  43,805  41,442  63,222             82,487 

Valued  at  ....      £389,258  £401,490  £400,975  £676,274  £1,005,913 

The  German  importations  of  caoutchouc  and  gutta-percha  for  the  past 
two  years  have  been  : 

1898.  1899. 

10, 097, 700  kilos.  13,916,400  kilos. 

Valued  at  54,528,000  marks.  Valued  at  75,149,000  marks. 

The  French  importations  for  the  same  period  were : 

1898.  1899. 

5, 312, 000  kilos.  6,128,200  kilos. 

Valued  at  32, 722,000  francs.  Valued  at  37,750,000  francs. 


RAW   MATERIALS. 


121 


CHAPTER  IV. 


THE   CANE-SUGAR   INDUSTRY. 

I.  Raw  Materials. 

ALTHOUGH  sucrose,  or  cane-sugar,  is  present  in  a  great  many  plants,  it 
is  usually  accompanied  by  relatively  large  quantities  of  other  carbohydrates, 
such  as  glucose,  starch,  etc.,  so  that  its  extraction  on  a  commercial  scale  is 
practically  impossible.  In  order  to  extract  the  cane-sugar  advantageously, 
glucose,  invert  sugar,  and  other  dissolved  solids  must  not  be  present  in 
amount  relatively  large  as  compared  with  the  sucrose.  If  this  ratio  of 
sucrose  to  total  dissolved  solids,  called  the  "coefficient  of  purity/'  falls 
below  a  certain  percentage  (usually  put  at  sixty-five),  the  plant-juice  can- 
not be  economically  worked  for  the  extraction  of  crystallized  cane-sugar. 
At  the  present  time  the  sucrose  is  extracted  from  four  diiferent  sources,  and 
on  what  may  be  termed  a  commercial  scale  from  two  only. 

1.  THE  SUGAR-CANE. — The  sugar-cane  belongs  to  the  family  of  grasses, 
growing,  however,  to  an  exceptionally  large  size.  The  plant  is  known 
as  Saccharum  officinarum,  and  the  best  known  varieties  are  called  by  such 
names  as  Bourbon  cane,  Otaheite  purple  cane,  ribbon  cane,  crystalline  cane, 
and  Java  cane.  It  has  a  wide  range,  succeeding  in  almost  all  tropical  and 
sub-tropical  countries,  and  requires  a  warm,  moist  climate,  developing  most 
luxuriantly  on  islands  and  sea-coasts  in  the  tropics.  It  is  the  richest  in 
sugar  of  all  the  plants  cultivated  for  this  purpose.  Under  ordinary  favor- 
able conditions  it  yields  about  ninety  per  cent,  of  juice,  which  contains 
eighteen  to  twenty  per  cent,  of  cry  stall  izable  cane-sugar.  The  following 
analyses  of  sugar-canes  from  several  sources  illustrate  its  composition : 


Martinique. 
(Peligot.) 

Guadeloupe. 
(Dupuy.) 

Mauritius, 
(leery.) 

Martinique. 
(Popp.) 

MiddleEgypt. 
(Popp.) 

Upper  Egypt. 
(Popp.) 

Water  .  . 
Sucrose  .  . 
Glucose 

72.1 
1      18.0 

72.0 
17.8 

69.0 
20.0 

72.22 
17.80 
0  28 

72.15 
16.00 
2  30 

72.13 
18.10 
0  25 

Cellulose  . 
Salts  .  .  . 

|    9.9 

9.8 
0.4 

10.0 
0.7  to  1.2 

9.30 
0.40 

9.20 
0.35 

9.10 
0.42 

100.00 

100.00 

99.  7  to  100.2 

100.00 

100.00 

100.00 

The  most  successful  cultivation  of  the  sugar-cane  is  at  present  carried 
on  in  Cuba  and  other  West  Indian  islands,  although  largely  produced  in 
almost  all  tropical  countries. 

2.  SUGAR-BEET. — The  sugar-beet  is  a  source  of  sucrose  that,  while 
first  mentioned  as  long  ago  as  1747,  when  Marggraf  called  the  attention 
of  the  Berlin  Academy  of  Sciences  to  its  importance  as  a  sugar-yielding 
material,  has  only  in  the  last  few  decades  advanced  to  great  importance  and 


122 


THE  CANE-SUGAR  INDUSTRY. 


taken  position  as  a  successful  rival  of  the  sugar-cane  in  the  matter  of  pro- 
duction. It  has  been  greatly  improved  by  careful  selection  and  cultivation, 
and  its  richness  in  sugar  notably  increased.  Marggraf  could  only  extract 
6.2  per  cent,  of  sugar  from  the  white  and  4.5  per  cent,  from  the  red  beet ; 
it  has  now  been  brought  to  an  average  of  eleven  per  cent.,  and  in  excep- 
tional cases  has  been  found  to  contain  sixteen  per  cent.  Some  six  varieties 
are  now  cultivated  in  Germany,  where  the  beet-sugar  industry  has  reached 
its  highest  development :  the  white  Silesian,  the  Quedlinburg,  the  Siberian, 
the  French,  the  Imperial,  and  the  Electoral.  (The  beet  is  relatively  much 
more  complex  in  its  chemical  composition  than  the  sugar-cane,  and  the  ex- 
pressed juice  contains  a  number  of  organic  impurities  not  present  in  the 
juice  of  the  cane,  notably  of  the  class  of  nitrogenous  or  albuminoid  sub- 
stances. On  the  other  hand,  glucose,  or  invert  sugar,  which  is  frequently 
present  in  the  cane,  is  practically  absent  in  the  juice  of  fresh  beets.)  The 
detailed  composition  of  the  sugar-beet  is  seen  from  the  accompanying 
scheme  of  Scheibler.*  At  the  same  time  the  three  accompanying  analyses 
by  R.  Hofmann  gives  the  composition  of  three  types  of  beets  :  those  poor  in 
sugar,  those  of  medium  richness,  and  those  containing  the  largest  percentage. 


First  type. 

Second  type. 

Third  type. 

Water  

8920 

83.20 

75.20 

4.00 

9.42 

15.00 

Nitrogenous  compounds  

1.00 

1.64 

2.20 

4.13 

3.34 

4.23 

1.01 

1.50 

2.07 

Ash   •  

0.66 

0.90 

1.30 

100,00 

10000 

100.00 

3.  SORGHUM  PLANT. — The  sorghum  plant  (Sorghum  saccharatum  and 
other  species)  has  been  known  and  valued  in  China  for  ages,  and  small 
quantities  have  been  cultivated  in  the  United  States  for  the  sake  of  the 
syrup  for  a  number  of  years  past.     It  is  only  of  recent  years,  however, 
that  attention  has  been  drawn  to  it  as  a  source  of  crystallized  sugar,  chiefly 
by  the  experiments  of  the  United  States  Bureau  of  Agriculture,  and  its 
systematic  cultivation  has  been  attempted  in  several  parts  of  the  United 
States.     The  composition  and  saccharine  strength  of  the  juice  seems  to  be 
quite  variable,  and  dependent  upon  conditions  of  cultivation  to  a  much 
greater  extent  than  is  the  case  with  either  the  sugar-beet  or  the  sugar-cane. 
Thus,  in  1883  the  mean  per  cent,  of  sucrose  in  the  sorghum  juice,  analyzed 
by  the  chemists  of  the  department,  was  8.65,  in  1884  the  mean  was  14.70 
per  cent.,  in  1885  it  was  9.23,  and  in  1886  it  was  8.60  per  cent.     The 
sorghum  plant  grows  easily  over  a  very  wide  range  of  climate,  and  if  its 
cultivation  can  be  established  definitely  upon  correct  principles,  it  may  prove 
to  be  a  most  valuable  addition  to  the  world's  sugar-producing  materials. 

4.  THE    SUGAR-MAPLE. — The  sap  of  Acer  saccharinum  and  other 
species  of  the  genus  Acer  is  a  source  of  sugar  and  syrup  more  esteemed 
for  confectionery  and  table  use  than  because  of  its  commercial  importance. 
The  sugar  is  never  refined,  and  only  comes  into  use  as  a  raw,  small-grained 

*  Bericht  iiber  Entwick  Chem.  Ind.,  von  Hofmann,  1877,  3te  Heft,  p.  187. 


EAW  MATERIALS. 


123 


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Solid  substance  of  the  juice. 


124 


THE  CANE-SUGAR  INDUSTRY. 


sugar  of  peculiar  and  characteristic  flavor ;  the  syrup  is  a  thin,  sweet 
syrup  of  the  same  characteristic  maple  flavor,  differing  considerably,  too,  in 
its  composition  from  both  cane-  and  beet-sugar  syrups.  The  freshly-collected 
sap  contains  from  two  to  four  per  cent,  of  sucrose,  with  traces  of  glucose. 

We  may  now  compare  the  chemical  composition  of  the  freshly-expressed 
juice  from  the  three  sources  of  sugar  manufacture  above  described,  and  note 
those  differences  which  are  of  importance  in  determining  the  successful  ex- 
traction and  crystallization  of  the  cane-sugar. 

The  composition  of  the  fresh  juice  of  the  sugar-cane  is  illustrated  in  the 
following  table.  The  first  four  analyses  are  by  the  United  States  Bureau  of 
Agriculture  and  were  made  in  connection  with  its  experimental  work,  and  the 
last  six  from  experimental  cultivation  of  certain  varieties  of  cane  in  Cuba 
on  the  Soledad  estate  of  Mr.  E.  Atkins. 


LOUISIANA. 

CUBA. 

1884. 

1885. 

1886. 

1887. 

Crystalline 
cane. 

Red  ribbon 
cane. 

Black  Java 
cane. 

Specific  gravity  . 
Total  solids  .  .  . 
Sucrose  .... 

1.068 
16.54 
13.05 
0.67 

0.19 
78.97 

15!80 
12.11 
1.02 

0.16 
76.64 

1.066 
16.20 
13.50 
0.61 

0.167 
83.33 

1.066 
16.37 
13.69 
0.77 

83.48 

11.6°  B. 
20.9 
19.2 
0.66 
Non- 
sugar. 
1.04 

91.8 

12.5°  B. 
22.6 
20.5 
0.20 
Non- 
sugar. 
1.90 

907 

11  2°  B. 
20.2 
18.5 
0.14 
Non- 
sugar. 
1.56 

91.5 

12.1°  B. 
21.9 
20.0 
0.31 
Non- 
sugar. 
1.69 

91.3 

12.2°  B. 
22.0 
21.3 
Trace. 
Non- 
sugar. 
0.70 

96.8 

11.8°  B. 
21.4 
20.6 
0.08 
Non- 
sugar. 
071 

96.3 

Glucose 

Albuminoids  .  . 
Coefficient        of 
Duritv 

The  average  composition  of  the  fresh  beet  juice  is  shown  in  the  follow- 
ing analyses,  the  method  of  obtaining  the  juice  being  also  indicated.  The 
first  four  are  from  "  Stammer's  Lehrbuch,"  and  represent  each  the  average 
of  a  German  beet-sugar  factory  for  the  season  ;  the  fifth  is  from  beets  culti- 
vated at  Washington,  D.  C.,  by  the  Bureau  of  Agriculture ;  the  sixth  the 
average  of  a  week's  work  at  Alvarado,  California,  in  1888,  and  the  last 
from  a  beet  grown  at  Grand  Island,  Nebraska,  and  analyzed  at  the  State 
Agricultural  Experiment  Station. 


German. 
By  press- 
ure. 

German. 
By  diffu- 
sion. 

German. 
By    cen- 
trifugat- 
ing. 

German. 
By    ma- 
ceration. 

Washing- 
ton. 
By  press- 
ure. 

Alvarado, 
Cal.* 
By   diffu- 
sion. 

Grand 
Island,  Neb.f 
H.  H.  Nichol- 
son. 

Total  solids  (degree 
Brix) 

1627 

17  20 

14  99 

18  77 

11.78 

17  20 

23  70 

Sucrose  

1302 

1463 

11  98 

14  64 

7  61 

14  80 

21  41 

Reducing  sugar    .    . 

0.39 

0  138 

Non-sugar     .... 
Coefficient  of  purity 

3.25 
80.02 

2.57 
85.14 

3.01 
79.92 

4.13 
77.99 

3.78 
64.60 

2.4 
85.5 

2.152 
90.3 

The  composition  of  the  sorghum  juice  of  different  seasons,  as  cultivated 
by  the  United  States  Department  of  Agriculture,  is  shown  in  the  following 
table: 

*  Many  beets  grown  near  Alvarado  in  the  fall  of  1888  polarized  twenty  per  cent.,  and 
the  average  coefficient  of  purity  for  the  season  was  estimated  to  be  from  eighty-five  to 
eighty-seven  per  cent. 

f  Individual  beets  grown  in  Nebraska  have  shown  a  percentage  of  22.08  sucrose,  and 
a  coefficient  of  purity  of  ninety-three  per  cent. 


PROCESSES  OF  TREATMENT. 


125 


1883. 

1884. 

1885. 

1886 

18 

87. 

Fort  Scott. 

Rio  Grande. 

Total  solids    ^    .    . 

13.59 

19.75 

1507 

17  08 

16  14 

14  02 

8.65 

14.70 

9.23 

9  59 

9  54 

8  98 

4.08 

1.27 

3.04 

4  25 

3  40 

3  24 

Non-suo'ar                            .    . 

086 

3  78 

2  80 

3  24 

3  20 

1  80 

Coefficient  of  purity 

63  65 

7443 

61  25 

56  15 

59  1,1 

64  05 

Analyses  of  fresh  maple-sap  made  at  Lunenburg,  Vermont,  by  one  of 
the  chemists  of  the  Department  of  Agriculture,  in  the  spring  of  1885,  shows 
that  it  contains  an  average  of  3.50  per  cent,  of  sucrose,  traces  only  of  glu- 
cose, about  .01  per  cent,  of  albuminoids,  and  has  a  mean  coefficient  of  purity 
of  95. 

n.  Processes  of  Treatment. 

1.  PRODUCTION  OF  SUGAR  FROM  THE  SUGAR-CANE. — As  the  cultiva- 
tion of  the  sugar-cane  is  chiefly  carried  on  in  the  tropical  countries,  parts 
of  which  are  dependent  upon  totally  unskilled  labor,  there  is  very  great 
diversity  in  the  development  which  the  industry  has  reached.  In  some 
countries  the  work  is  still  done  by  hand  or  with  the  simplest  kind  of  ma- 
chinery, with  corresponding  small  yield  of  inferior  products,  while,  in 
others,  as  in  Louisiana,  Demerara,  Cuba  and  other  West  Indian  islands, 
there  are  many  sugar  plantations  equipped  with  the  very  latest  and  best  of 
sugar-making  machinery,  and  producing  direct  from  the  juice  raw  sugars 
that  are  almost  equal  to  the  refined  product.  In  general,  however,  the 
sugars  produced  on  the  plantation  are  not  in  a  sufficiently  pure  condition  for 
consumption  and  are  termed  "  raw  sugars,"  having  therefore  to  undergo  a 
process  of  refining,  by  which  the  impurities  are  eliminated  and  the  sucrose 
obtained  in  a  pure,  well-crystallized  state.  We  shall  note  first  the  method 
of  producing  raw  sugar,  and  afterwards  the  methods  of  refining  the  same  at 
present  in  use. 

The  canes  must  be  cut  when  they  have  arrived  at  maturity,  and  must  be 
promptly  used  to  prevent  the  fermentation  of  the  albuminoid  constituents 
and  other  non-sugar  of  the  cane,  which  in  turn  rapidly  change  sucrose  into 
invert  sugar  and  lessens  the  possible  yield  of  crystallizable  sugar.  At  least 
this  immediate  use  of  the  cut  cane  is  necessary  in  Cuba,  Demerara,  and  dis- 
tinctly tropical  countries,  where  the  juices  must  be  expressed  within  forty- 
eight  hours  after  the  cutting  to  prevent  an  excessive  inversion  taking  place. 
In  Louisiana,  the  experiments  of  the  Department  of  Agriculture  have 
shown  *  that  sound  canes  can  be  kept  btored  under  cover  for  two  or  three 
months  without  appreciable  diminution  in  the  sucrose  per  cent,  or  loss  in 
the  coefficient  of  purity. 

The  expression  of  the  juice  has  been,  and  in  most  cases  still  continues 
to-  be,  effected  by  the  process  of  crushing  the  canes  between  heavy  rolls, 
which  may  vary  from  the  crude  stone  or  iron  rolls,  driven  by  water  or 
horse-power,  to  the  perfected  sugar-mills  now  in  use,  in  which  enormous, 
hollow,  steam-heated  rolls,  driven  by  steam,  are  used  to  do  the  same  work.  - 
Large,  slow-moving  rolls  have  been  found  in  practice  to  yield  better  results 

*  Bulletin  No.  5,  p.  57. 


126 


THE   CANE-SUGAR   INDUSTRY. 


than  smaller,  rapid-moving  rolls.  While  four,  five,  and  even  nine-roll 
mills  have  been  constructed,  the  mill  in  general  use  is  a  three-roll  mill,  an 
example  of  which  is  shown  in  Fig.  38.  The  canes  pass  by  the  carrier,  down 
the  slide,  through  the  rolls,  and  the  "  bagasse"  (exhausted  canes)  emerging 
below  is  carried  away  for  fuel  purposes,  while  the  juice  as  expressed  collects 
in  a  receptacle  and  is  run  to  the  evaporators. 

While  the  analyses  of  sugar-canes,  given  on  a  previous  page,  show  that 
the  cane  contains  ninety  per  cent,  of  juice,  the  percentage  of  extraction  of 
juice  by  this  roller-crushing  process  on  the  best-managed  Cuban  estates 
does  not  exceed  seventy  or  seventy-one,  and  generally  ranges  from  sixty 
to  sixty-five,  per  cent.  This  imperfect  liberation  of  the  cane  juice  by  the 
crushing  process  has  led  to  experiments  in  other  directions.  One  result  has 
been  the  frequent  introduction  of  a  second  or  supplementary  crushing  of 
the  cane  in  a  two-roll  mill  following  the  use  of  the  three-roll  mill  before 

FIG.  38. 


described.  These  second  rolls  are  heavier,  and  the  pressure  is  greater  than 
in  the  first  crushing.  The  total  percentage  of  juice,  and  consequently  of 
sugar  extracted  from  the  cane,  is  raised,  although  the  juice  from  the  second 
and  heavier  pressure  is  less  rich  in  sucrose  than  the  first  juice,  which  came 
from  the  softer  pulp  of  the  cane. 

It  has  also  been  sought  to  increase  the  yield  of  saccharine  juice  by  sub- 
mitting the  cane  to  the  action  of  hot  water  or  steam  at  an  intermediate  stage 
between  the  two  crushings.  It  is  stated  that  a  "  maceration"  process  of  this 
kind,  known  as  Duchassing's,  has  been  in  quite  successful  use  in  Guadeloupe, 
raising  the  yield  of  sugar  from  9.40  per  cent,  on  the  cane  to  11.04  per  cent. 

All  the  processes  hitherto  described  for  extracting  the  juice  from  the 
cane  have  depended  for  success  upon  the  rupture  of  the  juice-containing 
cells.  "  Diffusion,"  which  has  been  so  successful  in  the  extraction  of  the 
-juice  of  the  sugar-beet,  differs  from  them  essentially  in  dispensing  with 
the  breaking  up  of  the  cells,  and  in  substituting  therefor  a  displacement  by 
osmosis  or  diffusion  of  the  saccharine  juice  by  pure  water.  As  a  descrip- 
tion of  this  method  follows  when  speaking  later  of  the  treatment  of  the 


PEOCESSES  OF  TREATMENT. 


127 


128  THE  CANE-SUGAR  INDUSTRY. 

sugar-beet,  we  will  at  this  stage  speak  only  of  the  advantages  and  disad- 
vantages of  its  application  to  the  sugar-cane  work.  It  has  not  met  at  all 
with  general  favor  from  sugar-cane  planters.  Difficulties  were  met  with  in 
cutting  the  chips  needed  for  the  diffusion-cells.  The  sugar-cane  differs  so 
radically  in  its  structure  from  the  sugar-beet  that  totally  different  forms  of 
slicing  apparatus  had  to  be  used.  The  cane-chips  tended  to  pack  in  the  cells, 
and  so  impeded  the  circulation  of  the  warm  water.  When  this  took  place, 
fermentation  and  inversion  of  the  sucrose  rapidly  followed.  The  cane-chips, 
after  exhaustion,  do  not  make  as  good  a  fuel  as  the  bagasse  of  the  cane-mill. 
The  first  of  these  difficulties  has  been  overcome  both  in  the  use  of  diffusion 
apparatus  in  Guadeloupe  and  by  the  United  States  Department  of  Agricul- 
ture in  its  experiments  on  diffusion,  as  applied  to  the  sugar-cane  made  at 
Fort  Scott,  Kansas,  in  1886.  The  second  difficulty  has  in  part  been  over- 
come by  using  hotter  diffusion  water  (at  90°  C.),  and  working  more  rapidly 
with  a  sufficient  pressure.  But  it  is  more  effectually  prevented  by  the  use, 
in  the  diffusion-cells,  of  either  carbonate  of  lime,  as  proposed  and  patented 
by  Professor  M.  Swenson,  or  of  dry-slacked  lime,  as  proposed  by  Professor 
H.  W.  Wiley,  the  chemist  of  the  Department  of  Agriculture.  Of  these, 
the  latter  seems  to  meet  with  more  general  approval  of  those  who  have  tried 
diffusion  with  either  the  sugar-cane  or  the  sorghum-cane.  In  answer  to 
the  third  difficulty,  it  is  remarked  that  the  bagasse  burns  better  largely  be- 
cause of  the  notable  quantity  of  sugar  left  in  it,  and  that  when  the  diffusion- 
chips  are  dried  they  will  burn  fairly.  They  can  also  be  used  to  great  ad- 
vantage for  paper  stock  and  for  manure,  as  they  still  contain  most  of  the 
nitrogenous  constituents  of  the  cane.  On  the  other  hand,  if  successfully 
carried  out,  it  undoubtedly  effects  a  more  complete  extraction  of  the  sugar 
than  any  other  process.  At  Monrepos,  Guadeloupe,  with  Bouscaren's  ap- 
paratus, consisting  of  six  diffusors,  juice  having  a  density  nearly  equal  to 
that  of  the  natural  juice  is  obtained,  one  and  a  half  hours  being  sufficient 
for  extracting  the  sugar.  The  yield  of  white  sugar  amounts  to  twelve  and  a 
half  to  thirteen  per  cent,  of  the  weight  of  the  cane.*  At  Fort  Scott,  Kansas, 
the  chemists  of  the  Department  of  Agriculture,f  in  their  experiments  with 
diffusion  as  applied  to  sugar-canes,  succeeded  in  obtaining  a  yield  the  highest 
ever  got  from  sugar-cane.  The  mean  loss  of  sugar  in  the  chips  at  Fort 
Scott  was  .38  per  cent.,  and  the  quantity  of  sugar  present  was  9.56.  The 
percentage  of  extraction  was,  therefore,  ninety-six  per  cent.,  or,  reckoned  on 
the  weight  of  cane,  86.4  per  cent,  of  a  possible  ninety,  which,  if  compared 
with  the  best  figures  obtained  in  mill-crushing,  shows  a  decided  advantage 
for  diffusion. 

The  treatment  of  the  expressed  juice  is  next  to  be  noted.  This  has  also 
undergone  considerable  improvement  in  recent  years,  although  on  small 
isolated  sugar  plantations  the  primitive  and  wasteful  methods  of  the  "cop- 
per-wall," or  open-pan,  boiling  are  still  in  use.  The  general  outlines  of  the 
treatment  of  the  juice  which  is  followed  in  the  main,  if  not  always  in  detail, 
is  given  in  the  accompanying  scheme. 

The  juice  of  the  sugar-cane  must  be  properly  "defecated,"  or  treated 
with  milk  of  lime,  in  order  to  neutralize  the  organic  acids  of  the  juice,  and 
so  prevent  their  starting  a  fermentation  and  consequent  inversion  of  the 
sucrose  when  the  juice  is  heated.  This  has  the  effect,  as  soon  as  the  juice 
is  heated,  of  bringing  to  the  surface  a  thick  scum  of  lime  salts,  holding 

*  Spon's  Encyclopedia,  p.  1881.  f  Bulletin  No.  14,  p.  53. 


PROCESSES   OF   TREATMENT.  129 

mechanically  entangled  much  of  tne  albuminoids  and  suspended  particles  of 
fibre  of  the  juice.  This  is  known  as  the  "  blanket-scum."  This  is  removed 
by  skimming,  and  the  boiling  continued,  when  additional  greenish  scum 
forms,  which  is  similarly  removed.  When  the  scum  ceases  to  form,  the 
steam  is  shut  off  and  the  sediment  allowed  to  settle,  and  the  clarified  juice 
gradually  drawn  off.  The  amoant  of  lime  to  be  added  in  the  case  of  cane 
juice  is  usually  .2  to  .3  per  cent.,  or  about  four  ounces  of  quicklime  to  the 
gallon  of  juice,  but  is  always  carefully  controlled,  so  that  the  acid^  of  the 
juice  are  not  entirely  neutralized  and  a  faint  acid  reaction  still  remains. 
Should  the  lime  be  in  excess,  the  glucose  almost  always  present  in  the  cane 
juice  is  rapidly  acted  upon  and  decomposed,  yielding  dark-colored  products. 
An  excess  of  lime  is  always  corrected  before  further  treatment  by  the  addi- 
tion of  sulphurous,  sulphuric,  or  phosphoric  acids.  In  the  older  process  of 
open-pan  boiling,  this  defecating  and  clarifying  takes  place  in  the  first  of 
five  connected  kettles  or  pans,  walled  in  and  heated  by  the  same  fire,  and 
known  technically  as  the  "  copper-wall."  From  this  first  pan  the  juice,  after 
the  removal  of  the  blanket-scum,  goes  to  the  second,  in  which  it  receives 
more  heat.  A'fter  it  is  thoroughly  clarified  and  both  scum  and  sediment 
removed,  the  juice  goes  to  the  third  and  fourth  pans  successively,  in  which 
it  is  concentrated  to  30°  B.,  and  then  goes  to  the  fifth,  or  "  strike-pan,"  to 
be  brought  to  the  crystallizing  point.  It  may  still  require  some  treatment 
here,  as  it  first  becomes  thick.  If  "  sticky"  or  sour,  some  buckets  of  lime- 
water  are  let  in,  or  if  too  dark-colored,  dilute  sulphuric  acid  is  added  to 
clear  it.  When  the  "  masse-cuite,"  or  thick  mass,  full  of  separating  crys- 
tals, has  been  sufficiently  heated,  it  is  "  struck  out"  into  large,  shallow,  crys- 
tallizing vessels  and  allowed  to  cool,  and  so  complete  the  crystallization. 
The  older  open-pan  sugars  are  generally  "cured,"  or  freed  from  syrup, 
simply  by  draining  in  vessels  with  perforated  bottoms,  or,  in  a  limited 
number  of  cases,  by  the  process  of  "claying,"  or  covering  the  sugar  in 
cones  with  a  batter  of  clay  and  water,  through  which  water  percolates, 
slowly  displacing  the  darker  syrup.  The  first  method  gives  the  common 
"  muscovado"  sugar,  a  moist,  brown  sugar,  which  goes  from  the  West  Indies 
to  the  United  States  and  Europe  for  refining ;  the  second  method  gives  a 
lighter-colored  but  soft-grained  sugar,  which  similarly  must  be  refined  for 
use.  This  older  and  cruder  method  has  given  place  most  generally  now  to 
improved  methods,  whereby  the  yield  is  notably  increased  and  grades  of 
raw  sugars  are  produced  that  are  much  purer  and  finer  in  appearance.  The 
chief  improvements  consist  in  the  use  of  vacuum-pans  for  concentration  of 
the  juice  and  centrifugals  for  curing  the  crystallized  sugar.  At  the  same 
time  other  minor  improvements  contribute  no  little  to  the  better  results. 
The  juice,  unless  it  has  been  gotten  by  diffusion,  is  generally  run  through  a 
strainer  into  the  clarifier.  In  addition  to  very  careful  and  exact  measuring 
of  the  amount  of  "  temper-lime"  needed,  sulphurous  acid  or  sulphites  are 
often  used  now  to  bleach  the  juice.  In  case  sulphurous  acid  is  used, 
more  lime  is  needed  for  tempering.  The  thin  clarified  juice  is  then  filtered 
through  bone-black  filters  before  it  goes  to  the  vacuum-pan.  This  filtra- 
tion removes  the  vegetable  coloring  matters  as  well  as  the  finely  suspended 
impurities  that  remain. 

The  use  of  powdered  lignite  as  a  means  of  clarifying  and  improving  the 
raw-sugar  juices,  first  introduced  by  Kleeman,  has  been  tried  in  recent  years, 
and,  it  is  claimed,  with  success  and  profit.  It  is  added  after  the  juice  has 
been  limed  and  defecated,  and  the  juice,  together  with  the  accumulated 

9 


130 


THE   CANE-SUGAR   INDUSTRY. 


skimmings  and  bottoms  and  the  lignite,  are  thoroughly  mixed  and  then  im- 
mediately filter-pressed.  A  clear,  bright  juice  is  thus  obtained,  which  needs 
no  sulphuring  or  bone-black  filtration,  but  can  be  at  once  concentrated,  and 


FIG.  39. 


the  press-cakes,  after  washing,  make  excellent  fertilizer  material.  Lignite 
filtration  has  also  been  tried  in  the  clarifying  of  molasses,  but  with  little 
success  as  far  as  cane-sugar  molasses  is  concerned. 


PROCESSES   OF  TREATMENT. 


131 


The  most  important  improvement  in  the  preparing  of  a  better-grade 
sugar,  however,  consists  in  the  use  of  the  vacuum-pan,  by  means  of  which 
the  concentration  can  be  effected  with  the  least  heating,  and  hence  least 
discoloring  of  the  sugar-containing  juice.  The  vacuum-pan,  invented  in 
1813  in  England  by  Howard,  allows  of  the  concentration,  or  "  boiling  to 
grain/'  being  effected  at  temperatures  varying  from  130°  to  170°  or  180°  F., 
instead  of  the  240°  or  250°  F.  reached  in  the  open-pan.  They  are  of  vary- 
ing forms,  but  consist  essentially  of  a  spherical,  cylindrical,  or  dome-shaped 
copper  or  iron  vessel,  such  as  is  shown  in  Fig.  39.  The  contents  of  this 
vessel  are  heated  by  the  steam-coils  shown  in  the  cut,  and  the  vacuum  is 
maintained  by  the  connection  with  an  injector  air-pump,  as  shown.  The 
vacuum-pan  is  connected  first  with  an  overflow  vessel,  or  "  save-all,"  to 

FIG.  40. 


collect  saccharine  juice  thrown  over,  and  thence  with  the  exhaust-pump. 
Through  suitable  openings  in  the  side  of  the  pan  the  interior  can  be  illu- 
minated and  the  operations  watched ;  samples  can  be  withdrawn  by  the  aid 
of  the  "  proof-stick"  for  examination,  and  fresh  juice  can  be  admitted  when 
the  grain  is  to  be  built  up. 

In  concentrating  the  raw  juice,  considerable  use  is  made  of  what  are 
called  "  triple  effect"  vacuum-pans,  a  series  of  three  connected  pans,  in  the 
first  of  which  the  thin  juice  boils  under  a  slightly-reduced  pressure  and,  of 
course,  at  a  slightly  lower  temperature  than  in  the  air ;  the  vapor  from  the 
boiling  juice  here  passes  into  the  steam-drum  of  the  second  pan,  and 
readily  boils  the  liquor  here,  which,  though  denser,  is  under  a  greater 
vacuum,  and  similarly  the  vapor  from  this  liquor  boils  the  most  concen- 


132 


THE   CANE-SUGAR   INDUSTRY. 


FIG.  41. 


trated  juice  in  the  third  pan,  in  which,  by  the  aid  of  the  condensing-pump, 
a  very  perfect  vacuum  is  maintained.  Thus  large  quantities  of  juice  are 
evaporated  with  great  economy  of  fuel.  "  Double  effects"  are  also  used  in 
the  same  way.  These  triple  effects  have  been  much  improved  in  the  last 
few  years  by  the  modifications  introduced  by  Yaryan  and  Lillie,  both  of 
whom  adopt  the  plan  of  sending  the  sugar  juice  to  be  concentrated  through 
the  series  of  coils  while  the  steam  circulates  around  these  tubes.  A  general 
view  of  a  Yaryan  quadruple  effect  is  given  in  Fig.  40,  in  which  the  com- 
pact arrangement  of  the  evaporators  is  well  shown,  while  the  action  of 
the  Yaryan  apparatus  will  be  understood  from  Fig.  41,  giving  a  simplified 
section  through  one  of  the  pans  and 
"  catch-alls."  The  heating-tubes,  sur- 
rounded by  steam,  are  divided  into 
units  or  sections,  consisting  of  five 
tubes  coupled  at  the  ends  so  as  to 
form  one  passage.  Of  such  sections 
there  may  be  any  number.  The 
liquor  enters  the  first  tube  of  the  coil 
in  a  small  but  continuous  stream,  and 
immediately  begins  to  boil  violently. 
It  is  thus  formed  into  a  mass  of 
foam,  which  contains,  as  it  rushes 
along  the  heated  tubes,  a  constantly- 
increasing  portion  of  steam.  The 
mixture  is  thus  propelled  forward  at 
a  high  velocity,  and  finally  escapes  into  an  end  chamber  known  as  a  "  sep- 
arator," which  is  provided  with  baffle-plates. 

The  "  masse-cuite"  having  been  brought  to  sufficient  thickness,  the  whole 
or  a  part  of  the  contents  of  the  pan  are  "  struck  off."  If  half  the  contents 
of  the  pan  are  discharged  and  fresh  syrup  then  admitted  to  be  concentrated, 
the  crystals  obtained  at  first  grow  by  the  deposit  from  the  new  portion  of 
syrup.  This  process  of  admitting  successive  portions  of  fresh  syrup  after 
the  "  grain"  has  once  formed  is  used  in  the  development  of  large  crystals. 
It  must  be  used  with  judgment  though,  or  the  new  syrup  starts  a  new  set 
of  minute  crystals,  making  what  is  called  "  false  grain."  The  large  yellow 
Demerara  crystals  are  given  the  light  yellow  bloom  by  admitting  sulphuric 
acid  in  small  amount  after  the  grain  is  complete  and  just  before  the  "  strike." 
It  destroys  the  gray-green  color  of  the  raw-sugar  crystals  and  gives  instead 
a  pale  straw  color. 

After  the  "  masse-cuite"  has  left  the  pan,  the  crystallization,  except  in 
the  case  of  the  large  crystals,  is  completed  by  cooling,  and  the  sugar  must 
then  be  "  cured."  This  is  now  generally  effected  in  centrifugals  or  rotary 
perforated  drums.  A  form  in  common  use  for  sugar-work  is  shown  in  Fig. 
42.  Over  each  centrifugal  is  a  discharge-pipe  from  the  coolers ;  the  brown 
or  yellow  magma  is  let  in,  the  inner  drum  is  started  revolving,  and  the 
mass  heaping  against  the  perforated  sides  becomes  rapidly  lighter  in  color 
as  well  as  more  compact ;  the  syrup  flies  off,  and  from  the  space  between 
the  inner  and  outer  drums  runs  off  below  into  the  proper  receptacle.  The 
centrifugal  is  emptied  through  the  bottom  of  the  drums  by  raising  the  cen- 
tral spindle  and  with  it  the  detachable  plates  around  it,  so  that  a  circular 
opening  is  made  in  the  middle  of  the  apparatus. 

A  serious  loss  of  sugar  in  the  usual  method  of  working  is  in  the  scums, 


PROCESSES   OF  TREATMENT. 


133 


which  are  frequently  thrown  away.  Professor  Wiley,  the  chemist  of  the 
Department  of  Agriculture,  has  shown  *  that  in  working  a  crop  of  9063 
tons  of  cane  the  loss  of  sugar  in  the  scums,  if  thrown  away,  would  have 

amounted  to  120,316 

FIG.  42.  pounds,  of  which  94,- 

545  pounds  would 
have  gone  in  the 
blanket-scums,  -  and 
25,771  pounds  in  the 
subsequent  scums.  To 
save  this  sugar,  the 
scums  are  steamed  and 
then  pressed  and 
washed  in  a  filter- 
press  (see  p.  144), 
whereby,  practically, 
the  whole  of  the  sugar 
can  be  recovered.  The 
scums  are  generally 
filter-pressed  now  in 
the  best  Cuban  and 
Louisiana  sugar- 
houses,  although  a 
cruder  method  of 
pressing  them  in  bags 
is  used  on  some  plan- 
tations. The  applica- 
tion to  cane  juice  of 
the  method  so  gener- 
ally followed  in  the 
case  of  beet-sugar  of 
adding  an  excess  of 
lime,  which,  after  the 
the  first  boiling  up,  is 
removed  by  the  pro- 
cess of  carbonatation 
or  saturating  with  car- 
bonic acid  gas,  has 
generally  been  consid- 
ered to  be  impossible, 
because,  as  was  stated 
before,  an  excess  of 
lime  acts  injuriously 
upon  any  glucose  present  and  darkens  the  juice.  But  if  the  juice  is  from 
sound  canes  in  which  the  glucose  percentage  is  not  large,  the  advantages  of 
the  carbonatation  process  may  exceed  the  injurious  eifects.  This  seems  to 
have  been  shown  by  the  experiments  of  the  Department  of  Agriculture  at 
Fort  Scott,  Kansas,  in  the  fall  of  1886.  f  The  yield  of  sugar  in  the  ex- 
periments in  which  both  diffusion  and  carbonatation  were  followed  was,  as 
mentioned  before,  larger  than  had  ever  been  gotten  from  sugar-canes. 


*  Bulletin  of  Department  of  Agriculture,  No.  5,  p.  59.     f  Ibid.,  No.  14,  pp.  52  and  53. 


134 


THE   CANE-SUGAR   INDUSTRY. 


Professor  Wiley  sums  up  the  advantages  of  the  process  as  follows :  "  The 
process  of  carbonatation  tends  to  increase  the  yield  of  sugar  in  three  ways : 
(1)  It  diminishes  the  amount  of  glucose.  This  diminution  is  small  when 
the  cold  carbonatation,  as  practised  at  Fort  Scott,  is  used ;  yet  to  at  least 
one  and  a  half  its  extent  it  increases  the  yield  of  crystallized  sugar.  (2) 
By  the  careful  use  of  the  process  of  carbonatation  there  is  scarcely  any  loss 
of  sugar.  The  only  place  where  there  can  be  any  loss  at  all  is  in  the  press- 
cakes,  and  when  the  desucration  of  these  is  properly  attended  to  the  total  loss 
is  trifling.  The  wasteful  process  of  skimming  is  entirely  abolished,  and  the 
increased  yield  is  due  to  no  mean  extent  to  this  truly  economical  proceeding. 
(3)  In  addition  to  the  two  causes  of  increase  already  noted  and  which  are 
not  sufficient  to  produce  the  large  rendement  obtained,  must  be  mentioned 
a  third,  the  action  of  the  excess  of  lime  and  its  precipitation  by  carbonic 
acid  on  the  substances  in  the  juice  which  are  truly  melassigenic.  Fully 
half  of  the  total  increase  which  the  experiments  have  demonstrated  is  due 
to  this  cause.  It  is  true,  the  coefficient  of  purity  of  the  juice  does  not 
seem  to  be  much  affected  by  the  process,  but  it  is  evidence  that  the  treatment 
to  which  the  juice  is  subjected  increases  in  a  marked  degree  the  ability  of 
the  sugar  to  crystallize.  This  fact  is  most  abundantly  illustrated  by  the 
results  obtained.  Not  only  this,  but  it  is  also  evident  that  the  proportion 
of  first  sugars  to  all  others  is  largely  increased  by  this  method.  This  is  a 
fact  which  may  prove  of  considerable  economic  importance." 

It  only  remains  to  notice  in  connection  with  raw  sugars  two  forms  of 
apparatus  for  concentrating  raw-sugar  juice  which  have  had  considerable  use 

FIG.  43. 


in  the  tropics.  The  first  of  these  is  the  "  Wetzel  pan,"  an  apparatus  shown 
in  Fig.  43.  As  seen,  it  consists  of  a  pan  containing  the  liquor,  in  which  dip 
pipes  heated  by  steam  passing  through  them ;  while  the  cylinder,  formed 
by  these  pipes,  is  caused  to  revolve  by  power  applied  from  the  end  as  shown 
in  the  cut.  The  large  heating  surface  enables  steam  at  very  low  pressure 
to  be  used,  exhaust  steam  from  the  cane-mill  engine  being  sometimes  used 
for  the  purpose.  Such  pans  are  used  on  some  plantations,  in  the  absence 
of  a  vacuum-pan,  to  finish  the  concentration  begun  in  the  battery  or  copper- 
wall.  The  liquor  is  brought  to  them  at  a  density  of  26°  to  27°  B.  The 
other  form  of  apparatus  referred  to  is  the  "  Fryer  Concretor,"  in  which  no 


PROCESSES   OF  TREATMENT.  135 

attempt  is  made  to  produce  a  crystalline  article,  but  only  to  evaporate  the 
liquor  to  such  a  point  that  when  cold  it  will  assume  a  solid  (concrete)  state. 
The  mass  is  removed  as  fast  as  formed,  and  being  plastic  while  warm  it  can 
be  cast  into  blocks  of  any  convenient  shape  and  size,  hardening  as  it  cools. 
In  this  state  it  can  be  shipped  in  bags  or  matting,  suffering  neither  deli- 
quescence nor  drainage.  The  "  concretor"  consists  of  a  series  of  shallow 
trays  placed  end  to  end  and  divided  transversely  by  ribs  running  almost 
from  side  to  side.  At  one  end  of  these  trays  is  a  furnace,  the  flue  of  which 
runs  beneath  them,  and  at  the  other  end  a  boiler  and  an  air-heater,  which 
utilize  the  waste  heat  from  the  flue,  employing  it  both  to  generate  steam  and 
to  heat  air  for  the  revolving  cylinder.  The  clarified  juice  flows  first  upon 
the  tray  nearest  the  furnace,  and  then  flows  down  the  incline  towards  the 
air-heater,  meandering  from  side  to  side.  While  flowing  thus  it  is  kept 
rapidly  boiling  by  means  of  the  heat  from  the  furnace,  and  its  density  is 
raised  from  about  10°  B.  to  30°  B.  From  the  trays  it  goes  into  a  hollow 
revolving  cylinder  full  of  scroll-shaped  iron  plates,  over  both  sides  of  which 
the  thickened  syrup  flows  as  the  cylinder  revolves,  and  thus  exposes  a  very 
large  surface  to  the  action  of  hot  air  which  is  draAvn  through  by  a  pan. 
In  this  cylinder  the  syrup  remains  for  about  twenty  minutes  and  then  flows 
from  it  at  a  temperature  of  about  91°  to  94°  C.,  and  of  such  consistency 
that  it  sets  quite  hard  on  cooling. 

Raw  sugars  are  often  gotten  now  of  sufficient  purity  to  allow  of  their 
immediate  use  without  further  treatment.  Such  is  not  the  usual  rule,  how- 
ever, but  they  have  to  undergo  a  purifying  or  refining  in  order  to  bring 
them  to  the  requisite  purity  for  consumption.  The  sugar-refining  process 
is  simpler  in  its  theory  than  the  process  of  preparing  the  raw  sugars,  but 
requires  more  exactitude  in  its  execution,  and  more  elaborate  and  costly  ma- 
chinery and  equipment.  The  problem  as  stated  is  a  much  simpler  one  than 
was  that  of  handling  the  raw  cane  juice ;  it  is  now  simply  a  redissolving  of 
the  impure  crystalline  mass  of  raw  sugar,  freeing  the  solution  from  impuri- 
ties, and  then  crystallizing  afresh  the  pure  sugar  from  it.  The  sugar  refinery 
located  in  a  large  commercial  centre  is  almost  always  a  building  of  consid- 
erable height,  so  as  to  allow  of  the  descent  by  gravity  of  the  sugar  solutions 
from  floor  to  floor  as  the  process  of  treatment  proceeds.  The  general  out- 
line of  the  treatment  will  be  easily  followed  with  the  aid  of  the  diagram  in 
Fig.  44.  The  raw  sugars  as  they  arrive  are  discharged  from  hogsheads  or 
bags  in  the  mixing  room  on  the  ground  floor  through  wide  gratings  into 
the  melting  tanks,  or  "  blow-ups,"  just  below,  where  boiling  water  and  steam 
rapidly  dissolve  all  that  is  soluble  in  the  sugars.  These  tanks  hold  from 
three  thousand  to  four  thousand  five  hundred  gallons,  and  treat  from  nine 
to  thirteen  tons  of  sugar  at  a  time.  The  hogsheads  and  bags  are  similarly 
cleaned  out  by  live  steam.  The  crude-sugar  solution,  run  through  a  coarse 
wire  strainer  to  remove  mechanically-mixed  impurities,  is  then  pumped  to 
the  defecating  tanks  at  the  top  of  the  building.  The  defecating  is  not  done, 
as  was  the  case  with  raw  juice,  with  lime,  but  with  some  form  of  albumen, 
as  bullock's  blood,  which,  coagulating  by  the  heat,  encloses  and  carries  with 
it  much  of  the  fine  suspended  impurities.  Fine  bone-black  is  also  some- 
times added  along  with  the  blood.  The  contents  of  these  defecating  tanks 
are  boiled  up  and  agitated  thoroughly  for  from  twenty  minutes  to  half  an 
hour,  when  the  clear  liquor  is  run  off  in  the  troughs  leading  to  the  bag- 
filters.  These  are  of  coarse,  thick  cotton  twill,  four  or  five  feet  long,  and 
but  a  few  inches  through.  These  filters  collect  the  fine  suspended  slime 


136 


THE   CANE-SUGAR   INDUSTRY. 


FIG.  44. 


DEFECATING 
Ull'l         TANKS. 


PROCESSES   OF   TREATMENT.  137 

which  would  not  settle  in  the  defecating  tanks.  It  has  been  found  impossi- 
ble to  replace  them  by  filter-presses  in  the  working  of  the  raw  cane  sugars 
at  present  in  the  market,  on  account  of  the  slimy  character  of  the  separated 
matter.  The  liquor,  now  containing  soluble  impurities  only,  has  a  brown 
color.  It  goes  from  the  storage-tanks  below  the  bag-filters  to  the  bone- 
black-filters.  These  filters,  immense  iron  tanks,  twenty  feet  high  and  eight 
feet  in  diameter,  open  through  man-holes  at  the  top  to  the  filter-room  floor. 
They  have  false  bottoms,  perforated,  over  which  a  blanket  is  fitted  to  pre- 
vent the  bone-black  from  flowing  through  with  the  liquid.  The  largest 
filters  hold  thirty  to  forty  tons  of  the  bone-black.  When  they  are  filled 
with  bone-black  the  man-hole  is  closed,  and  the  syrup  from  the  cisterns 
below  the  bag-filters  is  turned  on.  It  percolates  slowly  down,  is  allowed 
some  time  to  settle,  and  after  about  seven  hours  the  drawing  off  begins 
through  a  narrow  discharge-pipe.  The  filtered  syrup  is  caught  in  different 
tanks  as  it  becomes  deeper  in  color,  and  the  colorless  syrup  first  obtained 
used  for  the  finest  sugars,  and  so  on.  When  the  charge  has  run  out,  the 
sugar  remaining  in  the  charcoal  is  washed  out  by  running  through  fresh  or 
"  sweet"  water,  and  the  bone-black  must  be  reburned  before  it  can  again  be 
used.  From  three-quarters  to  one  and  a  quarter  tons  of  black  are  needed 
per  ton  of  sugar  decolorized,  according  to  the  quality  of  the  raw  sugars.  The 
liquor  is  now  ready  to  be  concentrated  in  the  vacuum-pan  and  brought  to 
the  crystallizing  point.  This  vacuum-pan  boiling  has  already  been  de- 
scribed under  raw  sugars.  The  processes  of  boiling  are  somewhat  different 
for  "  mould"  and  for  "  soft"  sugars.  The  best  grades  of  syrup  boiled  to  an 
even,  good-sized  grain  are  used  for  the  former,  whether  loaf,  cut,  crushed, 
or  pulverized.  As  the  "  masse-cuite"  cools  it  is  run  into  conical  moulds 
with  a  small  aperture  at  the  bottom,  or  smaller  end,  through  which  the  un- 
crystallized  liquid  may  drain  off.  After  this  has  been  allowed  to  drain, 
water  or  white  syrup  is  poured  in  at  the  top,  which  washes  the  crystals  as 
it  slowly  filters  through.  After  a  sufficient  time  allowed  for  drainage,  the 
moulds  are  turned  over,  so  that  the  small  quantity  of  syrup  in  the  point  of 
the  cone  shall  distribute  itself  through  the  mass.  The  result  is  the  hard 
white  "  sugar-loaf,"  or  conical  form  of  sugar.  The  process  of  draining  in 
moulds  is,  however,  very  generally  replaced  by  the  use  of  large  centrifugals, 
in  which  several  cones  can  be  dried  at  a  time  in  a  few  minutes,  saving  enor- 
mously in  time  and  in  the  room  previously  occupied  by  the  large  number  of 
moulds  needed  for  several  days'  working.  Such  a  hydro-extractor  for  cones 
is  shown  in  Fig.  45.  The  "  soft"  sugars,  the  crystallization  of  which  is 
completed  in  the  cooler  after  the  "  masse-cuite"  leaves  the  vacuum-pan,  are 
cured  mostly  by  centrifugals,  and  are  ready  for  barrelling  on  leaving  them. 

2.  PRODUCTION  OF  SUGAR  FROM  THE  SUGAR-BEET. — In  considering 
the  question  of  the  production  of  sugar  from  the  sugar-beet,  two  things 
must  be  noticed  :  first,  the  soft,  pulpy  character  of  the  beet,  which  allows  of 
much  more  complete  extraction  of  the  juice,  and,  second,  the  more  complex 
composition  of  the  juice,  which  necessitates  more  elaborate  methods  of  puri- 
fication of  the  juice. 

The  cultivation  and  working  of  the  sugar-beet  has  been  developed  to 
so  much  greater  an  extent  in  Germany  than  any  other  country  that  we  shall, 
in  describing  the  extraction  of  sugar  from  the  beet,  notice  German  methods 
chiefly.  The  beets  are  first  washed,  brushed  and  deprived  of  the  tops,  and 
then  made  to  yield  their  juice  by  one  of  four  methods  :  (1)  by  pulping  them 
and  pressing  the  pulp  either  in  hydraulic  presses  or  between  rolls ;  (2)  by 


138 


THE   CANE-SUGAR   INDUSTRY. 


centrifugating  the  pulp ;  (3)  by  the  maceration  process,  in  which  the  pulp 
is  exhausted  with  either  warm  or  cold  water,  and  the  residue  pressed ;  and 
(4)  by  the  diffusion  process,  in  which  the  beets  are  not  pulped  at  all,  but 
are  cut  into  thin  transverse  sections,  known  in  Germany  as  "  schnitzel,"  in 
France  as  "  cosettes,"  and  in  English  as  "  chips."  These  are  then  put  into 
a  series  of  vessels,  in  which  a  current  of  warm  water  is  made  to  displace 
the  sugar  juice  by  the  principle  of  "  osmosis,"  or  diffusion,  as  it  is  more 
generally  called.  The  first  three  processes  are  now  almost  entirely  displaced 
in  Germany  by  the  diffusion  process.  It  is  obvious  that  in  this  latter  the 
juice  will  be  freer  from  the  fine  mechanically  suspended  impurities  and 

FIG.  45. 


solid  particles  than  in  the  processes  that  rupture  the  cell-walls.  In  this 
country  the  beet-sugar  factories  have  all  been  equipped  with  diffusion 
batteries  of  approved  construction,  and  that  method  has  been  the  one  ex- 
clusively employed.  In  France  the  diffusion  method  has  not  become  so 
generally  popular.  As,  however,  it  yields  a  purer  juice  and  a  higher  per- 
centage of  the  same  than  the  older  methods,  and  is,  as  just  stated,  the  one 
that  is  displacing  the  others,  we  shall  confine  ourselves  to  it. 

In  the  diffusion  method  of  Robert,  the  fresh  beets  are  cut  into  slices  or 
"chips"  of  about  one  millimetre  thickness,  which  are  digested  with  pure 
water  at  from  50°  C.  to  60°  C.  This  allows  the  saccharine  beet  juice  to  pass 
through  the  cell- walls  and  mix  .with  the  water  and  the  water  to  replace  it 


PROCESSES   OF  TREATMENT. 


139 


in  the  cells,  while  the  colloid  non-sugar  remains  behind.  The  vessels  used 
for  this  diffusion  are  mostly  upright  iron  cylinders,  as  shown  in  Fig.  46, 
which  are  provided  with  a  man-hole  above  for  charging  them  with  the  chips. 
A  series  of  these  diffusors  connected  together  is  known  as  a  battery.  They 
are  brought  to  the  proper  temperature  either  by  a  small  steam-coil  on  the 
bottom  of  the  vessel  or  by  so-called  "  calorisators,"  or  juice- warmers,  de- 
tached upright  heating  vessels  inserted  between  every  two  diffusors.  A 

FIG.  46. 


diffusion-battery  of  ten  cells,  with  juice-warmers,  is  shown  in  plan  in  Fig. 
47.  From  the  bottom  of  each  cell,  I  to  Jf,  goes  a  delivery-tube,  5,  to  the 
bottom  of  the  juice-warmer,  where  it  divides  into  seven  tubes.  From  the 
top  of  each  juice- warmer  a  tube,  a,  bent  at  right  angles,  connects  with  the 
next  cell.  The  connection  of  the  opposite  cells,  V  and  FJ,  as  well  as  the 
cells  X  and  I  at  the  other  end,  is  effected,  as  shown  in  the  ground-plan,  by 
longer  tubes  making  these  bends  at  right  angles.  By  suitable  valves  in  the 
supply-  and  delivery-tubes  each  cell  can  be  shut  off  from  the  others.  The 
upper  man-holes  of  the  cells  are  all  reached  from  the  platform  e,  which  runs 
along  just  above  them ;  the  valves  1,  2,  3  are  reached  from  the  platform  /, 
which  runs  along  lower  down,  supported  on  cross-pieces,  as  shown  in  Fig. 
48  ;  and  the  third  platform,  g,  gives  access  to  the  lower  valves.  A  sunken 
canal,  h,  in  this  lowest  platform  allows  of  the  exhausted  chips  being  dis- 
charged from  the  lower  man-holes  on  to-  an  endless  band,  which  passes 


140 


THE   CANE-SUGAR   INDUSTRY. 


around  two  wheels  and  delivers  them  into  ascending  buckets,  whence  they 
go  to  the  chip-press,  which  dries  them.     The  filling  of  the  cells  is  effected 


FIG.  47. 


by  means  of  a  swinging  trough,  not  shown  in  the  cut,  connecting  with 
chip-cutter  placed  on  a  higher  level. 


PROCESSES   OF  TREATMENT.  141 

In  operating  the  battery,  water  at  66°  C.  is  rim  into  the  first  cell,  which 
has  been  previously  filled  with  fresh  chips.  For  every  cubic  metre  of  space 
four  hundred  and  fifty  kilos,  of  chips  and  five  hundred  kilos,  of  water  are 
to  be  reckoned.  The  cell  remains  quiet  for  twenty  minutes,  during  which 
time  the  temperature  falls  to  45°  C.  The  connection  with  the  neighboring 
juice- warmer  is  now  opened,  and  the  thin  juice  made  to  pass  into  this  by 
forcing  fresh  cold  water  into  the  first  diffusion-cell.  The  juice,  brought  in 
the  warmer  to  66°  C.,  is  then  passed  into  the  second  cell,  which  has  been 
filled  with  chips.  After  twenty  minutes  the  juice  in  No.  2  is  passed  into 
the  adjoining  juice- warmer,  while  the  cell  fills  up  with  the  juice  from  No.  1, 
and  this  in  turn  with  fresh  water.  No.  3,  which  had  been  filled  meantime 
with  chips,  is  now  brought  into  the  connection.  After  the  juice  has  been 
kept  in  contact,  at  66°  C.,  with  the  contents  of  each  of  the  three  cells  in 
turn  for  twenty  minutes,  it  is  sufficiently  concentrated  to  go  to  the  defecating 
pan.  This  juice  is  therefore  sent  to  be  purified,  while  No.  3  fills  up  with 
the  thin  juice  from  No.  2.  In  twenty  minutes  this  is  displaced,  and,  after 
being  warmed  to  66°  C.,  goes  to  No.  4,  a  freshly-filled  cell.  After  suitable 
action  here  it  goes  direct  to  the  defecating  pan,  as  it  is  the  second  diifusate 
of  three  cells  and  the  first  of  a  fourth.  From  this  time  on,  as  a  new  cell 
comes  into  operation  the  juice  from  one  cell  goes  to  the  defecating  pan  until 
the  ninth  is  in  connection,  when  the  first  cell  is  disconnected  and  emptied  of 
the  exhausted  chips  and  then  filled  with  fresh.  While  this  is  going  on  the 
tenth  cell  has  been  connected ;  and  then  the  second  is  to  be  emptied,  while 
the  first  cell  is  brought  into  connection  with  the  tenth.  Thus  nine  cells  are 
always  working  together  in  the  battery,  while  the  tenth  is  disconnected  for 
emptying  and  filling. 

The  diffusion-cells  are  sometimes  arranged  in  a  semicircle  or  a  circle 
instead  of  a  straight  line,  as  this  arrangement  is  thought  to  be  more  con- 
venient when  the  cells  are  to  be  filled  and  emptied.  Such  a  circular  diffusion- 
battery  is  shown  in  Fig.  48,  and  the  method  of  filling  the  cells  with  the  chips 
or  slices  is  shown,  as  well  as  the  endless  belt  carrying  up  the  buckets  of 
exhausted  chips  to  be  emptied.  A  continuous  diffusor,  consisting  of  one 
long  cell,  in  which  the  chips  and  water  move  in  opposite  directions,  so  that 
as  the  juice  becomes  more  concentrated  it  shall  meet  chips  richer  and  richer 
in  sugar,  has  also  been  devised. 

As  stated,  the  percentage  of  extraction  by  these  methods  is  higher  and 
the  juice  is  purer  than  by  any  other  method,  while  the  dried  chips  also  serve 
as  most  valuable  fertilizer  material  or  for  cattle  food.  Their  average  com- 
position is  :  ash,  5.67  ;  fat,  .49  ;  crude  fibre,  23.36  ;  crude  protein,  8.70 ; 
and  non-nitrogenous  extractives,  61.78.  A  modification  of  this  diffusion 
process  by  Bergreen,  already  found  advantageous  in  practice,  is  to  exhaust 
the  cells  of  air  after  filling  them  with  fresh  beet-chips,  and  then  to  allow 
expanded  steam  to  enter,  so  as  to  coagulate  the  albuminoids.  The  usual 
procedure  then  follows.  The  exhausted  chips  gotten  this  way  make  a  good 
cattle  food,  as  they  are  richer  in  nitrogenous  matter.  The  beet  juice,  by 
whichever  of  the  four  methods  before  mentioned  it  may  be  gotten,  is  now  to 
be  purified.  The  general  outlines  of  the  method  of  working  up  the  juice  is 
shown  on  the  accompanying  diagram,  based  on  that  of  Post,*  but  modified 
to  accord  with  recent  improvements.  Except  in  the  case  of  the  diffusion 
juice  of  Bergreen's  process  mentioned  above,  the  crude  juice  is  heated  by 

*  Post,  Chemische  Technologie,  ii.  p.  274. 


142 


THE   CANE-SUGAR   INDUSTRY. 


FIG.  48. 


•pr 


PROCESSES   OF   TREATMENT. 


143 


s 


gs 

K  Oj 

J3  MJ 

2.^ 

Clipped  into  slices  (wi 
ing  the  cell-walls),  i 
diffused. 

i| 

II 


w 

c 
r 


w 


w 

3 

o 

» 

K 


o 
o 


w 
w 
w 
^ 

CO 

c 

Q 

» 


144 


THE   CANE-SUGAR   INDUSTRY. 


indirect  steam  to  80°  C.  to  coagulate  the  albuminoids,  and  then  two  to 
three  or  even  four  per  cent,  of  caustic  lime,  in  the  form  of  milk  of  lime,  is 
added.  This  lime  saturates  the  free  acids  and  throws  out  nitrogenous  com- 
pounds as  in  the  case  of  cane  juice,  and,  because  of  its  excess,  forms  soluble 
calcium  saccharates  with  some  of  the  sugar.  Carbonic  acid  gas  is  then 
added  until  the  precipitated  carbonate  of  lime  becomes  granular  and  settles 
readily.  At  this  time  there  still  remains  a  slight  excess  of  free  lime, — about 
.1  to  .2  per  cent.  The  contents  of  the  saturation-pan  are  now  pumped  into  the  • 
filter-presses  and  the  press-cakes  washed  free  from  sugar  by  steam.  A  filter- 
press,  such  as  is  adapted  for  sugar-scums  and  carbonatation  press-cakes,  is 
shown  in  Fig.  49.  This  treatment  is  called  the  first  carbonatation.  The  juice 
may  be  filtered  now  at  once  through  bone-black,  which  will  withdraw  the 
remaining  lime  as  well  as  decolorize  it,  but  in  most  German  sugar-houses 
it  is  subjected,  boiling  hot,  to  a  second  treatment  with  one-half  per  cent,  of 
lime,  and  then  completely  neutralized  with  carbonic  acid.  This  is  called  the 
second  carbonatation,  or  the  saturation.  After  again  going  through  the  filter- 
press  the  juice  goes  to  the  bone-black-filters.  In  many  of  the  newer  German 
sugar-houses  the  filtration  of  the  thin  juice  through  bone-black  is  no  longer 

FIG.  49. 


practised,  as  repeated  saturations  with  lime  and  carbonic  acid  or  treatment 
with  sulphurous  acid  and  sulphites  have  so  clarified  it  as  to  make  bone-black 
unnecessary.  It  is  stated  that  at  Watsonville,  California,  in  the  beet-sugar 
factory  of  Spreckels,  bone-black  filtration  is  thus  dispensed  with.  The  thin 
filtered  juice  is  concentrated  in  double  or  triple  effect  vacuum-pans  to  24° 
or  25°  R,  and  then  filtered  again  as  thick  juice  through  bone-black.  This 
second  filtration  takes  the  last  traces  of  nitrogenous  materials  out,  and  the 
remnant  of  lime  which  remained  in  solution.  It  is  then  concentrated  in 
the  vacuum-pan  to  crystallization. 

In  the  preparation  of  raw  sugar,  the  "  masse-cuite"  is  dropped  from  the 
vacuum-pan  into  small  coolers  of  about  two  hundred  kilos,  capacity,  in 
which  it  becomes  cold  and  crystallization  is  completed.  The  contents  of 
these  coolers  are  then  mixed  and  broken  up  and  rubbed  to  a  paste  with  the 
aid  of  some  syrup,  and  the  whole  centrifugated.  The  sugar  so  obtained  is 
the  raw  beet-sugar  of  commerce.  The  syrup  obtained  is  concentrated  in  a 
vacuum-pan,  and  the  sugar  from  this  forms  the  second  product,  which  some- 
times goes  into  commerce  and  sometimes  is  returned  to  the  thick  juice  to  be 
worked  up  with  it. 


PROCESSES   OF   TREATMENT.  145 

As  was  stated  before,  raw  cane-sugar  can  be  obtained  by  care  and  with 
the  best  vacuum-pan  practice  so  nearly  pure  as  to  be  directly  available  for 
use  without  any  special  refining.  In  the  case  of  raw  beet-sugar  this  is 
much  more  difficult.  The  raw  beet-sugar,  though  it  may  be  well  crystal- 
lized, usually  contains  substances  of  decidedly  unpleasant  odor  and  taste, 
chiefly  decomposition  products  of  the  betaine  of  the  juice  (see  composi- 
tion of  the  beet,  p.  123),  which  are  in  the  syrup  adhering  to  the  crystals. 
The  production  of  a  well-crystallized  sugar  for  consumption  direct  from 
the  beet  juice  requires,  therefore,  a  thorough  cleansing  of  the  crystals  in  the 
centrifugating  process.  This  is  accomplished  by  the  purging  of  the  crystals 
with  a  clear  white  syrup,  which  displaces  the  impurer  syrup  adhering,  or 
very  generally  by  the  use  of  steam  of  low  tension  either  admitted  into  the 
inner  drum  of  the  centrifugal  or  to  the  space  between  the  revolving  drum 
and  the  mantel.  In  this  last  case  the  steam  does  not  so  much  cleanse  the 
crystals  as  it  warms  the  mass  and  liquefies  thoroughly  the  syrup  in  the 
spaces  between  the  crystals.  The  production  for  direct  consumption  of  a 
commoner  sugar,  known  in  Germany  as  "  melis,"  or  lump-sugar,  is  an  im- 
portant branch  of  the  raw  sugar-working.  In  this  case  the  contents  of  the 
vacuum-pan  brought  to  grain,  but  without  the  special  building  of  crystals, 
are  discharged  into  shallow  vessels  with  false  bottoms,  which  may  be  called 
"  warmers,"  in  which  the  "  masse-cuite"  is  heated  up  from  60°  to  90°  C., 
which  has  the  eifect  of  redissolving  most  of  the  small  crystals.  The 
warmed  syrup  is  now  filled  into  the  moulds,  in  which  it  crystallizes  uni- 
formly to  a  compact  whole.  This  grade  of  sugar  would  have  as  so  pro- 
duced a  light  yellow  color,  which  is  usually  corrected  by  the  addition  of 
ultra-marine  blue. 

Of  course,  raw  beet-sugar  can  be  most  advantageously  purified  by  a 
complete  refining  process,  analogous  to  that  described  under  cane-sugar,  in 
which  they  are  redissolved,  clarified,  decolorized,  and  again  crystallized. 
The  procedure  is  so  similar  to  that  described  under  the  refining  of  cane- 
sugar  that  it  need  not  be  specially  noticed  here. 

3.  THE  WORKING  UP  OF  THE  MOLASSES. — It  is  stated  in  the  tabular 
view  of  the  working  of  cane-sugar  on  p.  127,  that  the  molasses  is  used 
for  syrup  or  worked  over  into  molasses  sugars.  We  should  distinguish, 
however,  between  the  several  grades  of  molasses.  In  working  up  the  raw 
sugar  reference  was  made  to  first,  second,  and  third  sugars.  Corresponding 
to  each  of  these  three  grades,  of  course,  is  a  different  molasses,  sometimes 
known  as  first,  second,  and  third  molasses,  and  sometimes  as  second,  third, 
and  fourth  molasses.  The  average  percentage  of  sucrose  and  of  reducing 
sugars  in  these  is  shown  from  the  analyses  of  the  United  States  Department 
of  Agriculture  *  made  at  Magnolia,  Louisiana,  in  1884. 

First  molasses  .  .  Sucrose,  37.97  per  cent.  Reducing  sugar,  8.13  per  cent. 
Second  molasses  .  Sucrose,  41.23  per  cent.  Reducing  sugar,  18.82  per  cent. 
Third  molasses  .  .  Sucrose,  21.87  per  cent.  Reducing  sugar,  21.06  per  cent. 

The  percentage  of  solid  non-sugar  in  the  first  and  second  of  these 
molasses  will  nearly,  if  not  quite,  equal  that  of  the  sucrose,  while  in  the 
third  it  considerably  exceeds  it. 

The  "  first  molasses"  is  sufficiently  pure  to  be  mixed  with  syrup  sugar 
in  the  pan  for  the  production  of  a  second  product  sugar;  the  "second 

*  Bulletin  No.  5,  p.  52. 
10 


146  THE   CANE-SUGAR   INDUSTRY. 

molasses"  can  be  refined  as  such  for  brown  or  grocery  sugars,  and  the 
"  third  molasses"  is  so  sticky  and  impure  that  it  can  only  be  sent  to  the 
rum-distillery,  where  it  is  fermented  for  rum.  (See  p.  219.) 

With  respect  to  beet-root  molasses  the  case  is  diiferent.  It  is  very 
impure  from  mineral  salts  and  nitrogenous  materials,  but  is  nearly  pure 
from  the  invert  or  reducing  sugar  so  abundant  in  cane-sugar  molasses,  and 
in  recent  years  it  has  been  found  possible  to  work  it  specifically  for  the 
extraction  of  the  sucrose,  of  which  over  ninety  per  cent,  is  now  extracted, 
thus  reducing  the  loss  of  sugar  to  a  minimum.  The  average  composition 
of  beet-sugar  molasses  is  given  at  fifty  per  cent,  of  sucrose,  thirty  per  cent, 
of  non-sugar,  and  twenty  per  cent,  of  water.  Of  these  thirty  non-sugar, 
ten  are  made  up  of  inorganic  salts,  chiefly  potash  compounds,  and  twenty 
of  organic  non-sugar  (see  composition  of  the  sugar-beet,  p.  123).  As  the 
amount  of  beet-sugar  molasses  produced  in  Continental  Europe  annually 
is  estimated  at  250,000  tons,  the  fifty  per  cent,  of  sucrose  represents  125,000 
tons  of  sugar  which  it  was  certainly  desirable  to  extract  if  possible.  The 
processes  for  accomplishing  this  depend  upon  either  one  or  the  other  of  two 
principles:  either  to  withdraw  from  the  molasses  the  potash  and  other 
mineral  salts  which  prevent  the  crystallization  of  the  sucrose,  or  to  pre- 
cipitate out  the  sucrose  in  combination  with  calcium  or  strontium  as  an 
insoluble  sucrate,  which  is  then  mixed  with  water  and  decomposed  by 
carbon  dioxide  or  used  in  the  defecation  of  beet  juice  instead  of  lime. 

The  elimination  of  the  potash  salts  may  be  effected,  according  to 
Newland's  proposal,  by  the  addition  of  aluminum  sulphate  so  as  to  form 
potash  alum,  which  is  crystallized  out,  or  by  the  "  osmose"  process,  in 
which  the  principle  of  diffusion  already  referred  to  (see  p.  138)  is  again 
made  use  of.  In  this  case  advantage  is  taken  of  the  fact  that  the  potash 
salts  are  the  most  crystalline  constituents  of  the  molasses,  and  hence  will 
pass  through  a  sheet  of  vegetable  parchment  more  rapidly  than  the  other 
constituents.  So  if  the  molasses  warmed  to  80°  or  90°  C.  be  made  to  pass 
in  a  stream  on  the  one  side  of  such  a  membrane  while  pure  water  passes 
on  the  other,  the  potash  salts  diffuse  through,  and  are  to  that  degree  elimin- 
ated from  the  molasses.  However,  the  difference  in  the  rapidity  of  diffusion 
of  the  salts  and  the  sucrose  is  not  sufficiently  great  to  allow  of  a  very 
perfect  separation,  so  that  to  avoid  loss  of  sugar  the  operation  must  be 
stopped  before  the  elimination  of  salts  is  complete.  A  little  more  than 
half  of  the  sugar  can  be  recovered  from  the  molasses  in  this  way.  The 
apparatus  in  which  this  treatment  of  the  molasses  is  carried  out  is  known 
as  an  osmogene,  and  is  illustrated  in  Fig.  50.  It  consists  of  a  number  of 
very  narrow  but  high  and  deep  cells  adjoining  each  other,  the  sides  of 
which  are  of  parchment  paper.  Through  alternate  cells  in  this  system 
goes  the  heated  molasses,  and  through  the  intervening  cells  the  water  at  the 
same  temperature,  each  connecting  with  lateral  canals  for  the  supply  and 
withdrawal  of  the  respective  liquids,  The  ordinary  osmose  apparatus  of 
the  German  sugar-houses  is  capable  of  working  1000  kilos,  or  upAvards 
of  molasses  per  day,  and  at  a  cost  of  1.60  marks  (38.4  cents)  per  100  kilos, 
of  molasses.  The  osmose  sugar  is  somewhat  darker  in  color  than  ordinary 
second  or  third  sugar,  but  is  of  pleasanter  and  sweeter  taste.  The  yield  of 
the  osmose  process  varies  with  the  grade  of  the  molasses  taken ;  a  molasses 
with  a  purity  coefficient  of  fifty-eight  to  sixty  will  yield  ten  to  twelve  per 
cent,  of  the  molasses  taken,  and  one  of  a  coefficient  of  sixty  to  sixty-five  will 
yield  seventeen,  or  sometimes  as  high  as  twenty,  per  cent.  By  repeating  the 


PKOCESSES   OF   TREATMENT. 


147 


osmose  process  thrice  the  yield  can  be  raised  to  thirty  per  cent,  out  of  the 
possible  fifty  per  cent,  of  sucrose  contained  in  the  molasses. 

Of  the  methods  depending  upon  the  formation  of  a  lime  or  strontia 
sucrate,  the  most  important  are  the  Scheibler-Seyferth  elution  process,  the 
Steffen  substitution  and  separation  processes,  and  the  strontium  processes. 

In  the  first  of  these  processes,  finely  powdered  quicklime  is  added  to 
the  molasses,  which  has  been  previously  concentrated  in  vacuo  to  84°  or 
85°  Brix,  in  the  proportion  of  about  twenty-five  parts  of  the  farmer  to 

Fm.  50. 


on  a  hundred  parts  of  the  latter.  The  lime  slakes  at  the  expense  of  the 
water  of  the  molasses,  and  leaves  the  tribasic  calcium  sucrate  in  the  form 
of  a  dry  porous  mass.  This  is  then  broken  up  and  put  into  the  "  elutors," 
vessels  which  are  somewhat  similar  in  design  to  the  cells  of  a  diffusion- 
battery.  The  impure  sucrate  is  here  systematically  washed  with  thirty-five 
per  cent,  alcohol,  which  dissolves  away  from  it  most  of  the  adhering  im- 
purities. The  washed  sucrate  is  then  brought  to  the  condition  of  a  fine 
paste  with  water,  and  either  decomposed  with  carbon  dioxide  or  used 
instead  of  lime  in  treating  fresh  beet  juice.  This  process  takes  out  eighty- 
five  to  ninety  per  cent,  of  the  sugar  contained  in  the  molasses,  but  the  cost 
is  somewhat  greater  than  in  the  case  of  the  osmose  process.  The  alcohol  is 
recovered  from  the  washings  by  distillation.  Steffen's  substitution  process 
depends  upon  the  difference  in  solubility  of  the  tricalcium  sucrate  at  high 
and  low  temperatures.  The  molasses  is  first  diluted  so  that  it  shall  contain 
about  eight  per  cent,  of  sugar,  and  then  caustic  lime  added  until  some  two 
to  three  per  cent,  has  been  used.  The  whole  mass  is  then  heated  to  115° 
C.,  when  the  tricalcium  sucrate  is  precipitated  and  separated  by  the  use  of 
a  filter-press.  The  sucrate  is  ground  up,  again  filter-pressed,  and  then  can 
be  used  in  defecating  sugar  juice.  The  washings  from  the  filter-press  are 
used  to  dilute  a  fresh  quantity  of  molasses  to  the  degree  mentioned  before, 


148 


THE   CANE-SUGAK   INDUSTEY. 


which,  treated  with  lime  in  the  proper  proportion  and  heated  up,  separates 
the  sucrate,  which  is  treated  as  before.  After  about  the  twentieth  operation, 
the  cooled  mother-liquors  and  wash- waters  are  treated  with  lime  alone,  and 
the  residual  liquors  after  this  treatment  are  then  rejected.  In  the  Steffen 
separation  process,  on  the  other  hand,  the  molasses  solution  is  kept  cold, 
the  temperature  not  being  allowed  to  rise  over  30°  C.  (86°  F.).  The 
molasses  is  diluted  until  the  density  shows  12°  Brix,  the  percentage  of 
sugar  being  then  from  seven  to  eight.  This  solution  is  cooled  down  to 
15°  C.  (59°  F.),  and  finely-powdered  quicklime  is  added  in  small  portions 
at  intervals  of  about  a  minute,  the  temperature  rising  a  little  each  time  and 
being  again  cooled  down.  The  mixing  of  the  molasses  and  the  lime,  in  the 
proportion  of  fifty  to  one  hundred  of  powdered  lime,  according  to  quality, 
to  one  hundred  of  dry  sugar,  in  the  solution  takes  place  in  a  closed  mixing- 
vessel  of  iron  provided  with  tubes  through  which  cold  water  is  kept  circu- 
lating, and  with  a  mechanical  agitator  to  mix  the  contents  uniformly.  The 
insoluble  sucrate  separates  out  rapidly  in  the  cold,  and  the  contents  of  the 
mixer  A  (see  Fig.  51)  are  pumped  to  the  filter-press  E,  where  the  sucrate 

FIG.  51. 


is  washed,  the  mother-liquor,  containing  all  the  impurities  of  the  molasses, 
being  put  aside  for  fertilizing  purposes,  the  wash-water,  however,  being 
collected  in  F  for  use  in  diluting  new  quantities  of  molasses.  The  washed 
sucrate  drops  from  the  filter-press  into  the  sucrate-mill  G,  where  it  is  mixed 
to  a  thin  paste  with  water,  and  then  pumped,  by  means  of  the  monte-jus 
Hj  to  the  receptacle  J.  From  here  it  can  be  sent  into  the  first  saturation- 
vessel  K,  and  to  the  filter-press  Mt  and  to  the  second  saturation-vessel  S, 
and  the  filter-press  0. 

The  process  which  at  the  present  time  is  attracting  very  favorable 
attention  and  seems  to  give  considerable  promise  is  the  strontium  process. 
In  this  the  sugar  is  precipitated  either  as  monostrontium  sucrate,  which  is 
quite  difficultly'  soluble  in  the  cold,  or  as  bistrontium  sucrate  separating 
from  hot  solution.  According  to  Scheibler's  monosucrate  procedure,  the 
molasses  is  well  mixed  with  hot  saturated  strontium  hydrate  solution,  and 
the  mixture  passed  over  cooling  apparatus  into  crystallizing  tanks,  where  a 
few  crystals  of  the  monosucrate  are  added  to  start  the  crystallization.  After 


PROCESSES   OF   TREATMENT.  149 

some  hours  the  whole  mass  is  changed  into  a  crystalline  magma,  which  is 
broken  up  and  put  through  a  filter-press.  The  white  cakes  of  strontium 
sucrate  go,  as  in  the  case  of  calcium  sucrate,  to  the  treatment  of  crude  beet 
juice,  while  the  mother-liquor  is  treated  with  more  caustic  strontia  and 
boiled,  when  bistrontium  sucrate  is  precipitated.  This  is  dense  enough  to 
be  washed  by  decantation,  and  then  can  be  used  instead  of  strontia  solution 

FIG.  52. 


with  fresh  molasses  for  the  formation  of  monostrontium  sucrate.  The 
excess  of  strontia  is  recovered  from  all  the  mother-liquors  and  worked  over 
into  caustic  strontia.  By  the  other  strontium  process  the  molasses  is  added 
to  a  twenty  to  twenty-five  per  cent,  strontium  hydrate  solution,  both  taken 
hot,  in  such  amount  that  for  one  part  of  sugar  about  two  and  one-half  parts 
of  strontium  hydrate  are  present.  The  precipitated  bistrontium  sucrate 
separates  rapidly,  and  the  mother-liquor  can  be  decanted  from  it.  The 


150  THE   CANE-SUGAK  IKDUSTKY. 

sucrate  is  washed  with  hot  water  or  with  a  ten  per  cent,  hot  strontium 
solution.  In  order  to  decompose  the  sucrate,  it  is  brought  in  a  refrigerating 
chamber  and  cooled  to  10°  to  12°  C.,  when,  after  twenty-four  to  seventy- 
two  hours7  standing,  according  to  temperature,  etc.,  it  decomposes  into 
crystallized  strontium  hydrate  and  sugar  solution,  containing  something 
less  than  half  of  the  strontia.  After  filtering  off  the  crystallized  strontium 
hydrate,  the  sugar-liquor  is  decomposed  with  carbon  dioxide  in  the  usual  way. 

In  Germany  in  1891-92,  48  sugar-houses  extracted  by  the  'osmose 
process,  28  by  the  elution  and  precipitation  process,  3  substitution,  20 
separation,  and  1  strontian  process.  Osmose  produced  509,595  metric 
centners,  elution  548,476  metric  centners,  substitution  22,015  metric  cent- 
ners, separation  361,149  metric  centners,  and  the  strontian  process  14,765 
metric  centners  of  sugar. 

4.  REVIVIFYING  OF  THE  BONE-BLACK. — The  bone-black,  or  "  char," 
after  use  in  the  filters,  becomes  charged  with  impurities  and  loses  for  the  time 
its  decolorizing  power.  It  can,  however,  be  restored  to  activity,  or  "  revivi- 
fied," by  suitable  treatment  so  as  to  be  used  again  for  filtration,  and  this  pro- 
cess can  be  repeated  many  times  before,  by  the  gradual  loss  of  its  porous 
character  and  change  of  composition,  it  becomes  unfit  for  use.  In  working 
sugars  from  the  cane  this  revivification  is  a  much  simpler  process  than  in 
the  case  of  beet-sugars.  In  the  former  case,  water  as  hot  as  possible  is  run 
in  at  the  top  of  the  filter,  which  displaces  the  sugar  solution  remaining  in 
the  pores  of  the  char  and  forms  a  dilute  solution  of  sugar  and  the  soluble 
impurities  taken  up  from  the  liquor.  This  dilute  solution  is  known  as 
"  sweet-water,"  and  is  usually  boiled  down  in  triple  effects  and  run  in  with 
the  lower-grade  products.  After  running  additional  hot  water  through,  the 
filters  are  drained,  and  the  moist  char,  after  a  partial  drying,  is  put  into  the 
top  of  the  vertical  retorts,  in  which  it  is  to  be  heated  out  of  access  of  air 
for  the  decomposition  of  the  organic  matter  still  remaining  in  the  pores  and 
the  restoration  of  its  absorbent  power.  Various  forms  of  char-kilns  are  in 
use  in  different  refineries.  That  shown  in  Fig.  52  represents  one  of  the 
simpler  forms  of  char-kilns.  The  moist  spent  black  from  the  filters  in 
which  it  was  washed  goes  on  to  the  floor  H,  where  it  is  dried  by  the  waste 
heat  passing  through  G  and  F,  and  then  goes  into  the  openings  at  J,  which 
are  kept  always  heaped  up.  The  black  descends  in  the  retort-pipes  A  from 
the  upper  cooler  portions  into  the  middle  hottest  part,  and  then,  as  portions 
are  withdrawn  below,  into  a  cooler  section  again.  The  black  drawn  off  below 
is  protected  from  the  air  by  being  received  into  closed  receptacles  or  at  once 
filled  into  the  bone-black-filters.  In  other  forms  of  kilns,  the  retorts  are 
rotated  slowly  by  mechanism  so  as  to  heat  all  parts  equally. 

In  beet-sugar  refineries  the  revivifying  of  the  char,  as  before  stated,  is  a 
more  tedious  process.  This  is  in  part  because  the  juices  and  syrups  have 
been  limed  in  such  excess  in  the  preliminary  stages  of  treatment,  and  in 
part  because  the  beet  juice  contains  much  more  albuminoid  and  organic 
non-sugar,  which  is  absorbed  in  the  pores  of  the  char  and  cannot  be  gotten 
rid  of  by  simple  washing.  The  first  step  in  the  revivifying,  then,  in  this 
case,  is  a  treatment  with  a  calculated  amount  of  hydrochloric  acid  to  remove 
the  excess  of  carbonate  of  lime ;  after  this  a  thorough  washing  of  the  black 
in  special  washing-machines,  such  as  the  Klusemann  washer,  shown  in  Fig. 
53  ;  then  a  fermentation  to  decompose  into  simpler  and  soluble  constituents 
the  absorbed  albuminoids  and  other  organic  matter.  The  fermentation  may 
be  either  what  is  termed  the  dry  fermentation,  in  the  presence  of  a  very 


PROCESSES   OF   TREATMENT. 


151 


.  53. 


152  THE   CANE-SUGAR   INDUSTRY. 

small  quantity  of  water,  or  the  moist  fermentation  in  the  presence  of  a  larger 
amount.  The  first  takes  from  twelve  to  twenty  hours,  while  the  latter  re- 
quires from  six  to  seven  hours  only.  The  black,  after  the  fermentation,  is 
treated  with  boiling  alkaline  solutions,  washed,  and  then  burned  in  char-kilns 
as  already  described.  The  char  seems  to  improve  in  filtering  power  at  first, 
as  a  consequence  of  revivifying,  but  soon  loses  again  and  runs  down  steadily 
in  value.  This  is  in  large  part  due  to  the  separation  out  in  the  pores  of  car- 
bonized residue  from  the  burning.  This  carbon  has  no  decolorizing  power 
like  the  nitrogenized  carbon  of  the  original  bone-black,  but  simply  clogs  the 
pores  of  the  char  and  mechanically  obstructs  its  action. 

m.  Products  of  Manufacture. 

1.  RAW  SUGARS. — The  composition  of  the  juice  from  both  the  sugar- 
cane and  the  sugar-beet  has  been  stated,  and  the  processes  for  preparing  the 
raw  sugar  from  each  of  these  sources.  We  may  now  examine  more  closely 
the  character  of  the  products  obtained.  The  raw  cane-sugar,  made  as  it  is 
chiefly  in  the  tropics  under  a  variety  of  conditions  of  working,  from  the 
most  primitive  to  the  most  highly  improved,  has  come  into  commerce  under 
a  great  variety  of  names  as  well  as  of  varying  grades  of  purity.  The  raw 
beet-sugar  is  usually  known  as  first,  second,  or  third  product  sugar.  (See 
p.  143.) 

Muscovado  is  a  brown  sugar  produced  in  the  West  Indies,  generally  by 
open-pan  boiling,  which  has  been  drained  in  hogsheads  or  perforated  casks, 
and  so  freed  in  large  part  from  the  accompanying  molasses. 

Cassonade  is  a  name  formerly  applied  in  the  French  colonies  to  musco- 
vado sugars. 

Melada  is  a  moister  brown  sugar,  produced  like  the  muscovado,  but  not 
drained  free  from  molasses. 

Concrete,  or  concreted  sugar,  is  the  product  of  the  Fryer  concretor  (see 
p.  135)  or  similar  form  of  apparatus,  and  is  a  compact,  boiled-down  mass, 
containing  both  the  crystallizable  sugar  and  impurities  which  ordinarily  go 
into  the  molasses.  It  shows  little  or  no  distinct  grain. 

Clayed  sugars  have  been  freed  from  the  dark  molasses  by  covering  them 
in  moulds  by  moist  clay,  which  allows  of  a  gradual  washing  and  displace- 
ment of  the  adhering  syrup. 

Bastards  is  the  name  given  to  an  impure  sugar  gotten  by  concentrating 
molasses  and  allowing  to  crystallize  slowly  in  moulds. 

Jaggery  is  the  name  given  to  a  very  impure  East  Indian  palm-sugar, 
sometimes  refined  in  England,  but  chiefly  consumed  in  the  country  of  its 
production. 

Demerara  crystals  are  the  product  of  the  best  vacuum-pan  boiling  and 
have  been  well  purged  in  the  centrifugals.  They  have  the  light  yellow 
bloom  due  to  treatment  with  sulphuric  acid.  (See  p.  132.) 

These  Demerara  crystals  have  also  been  brought  to  the  United  States 
with  very  dark  brown  color.  This,  however,  was  only  superficial,  and 
was  capable  of  removal  by  centrifugating  with  a  lighter-colored  syrup. 
The  dark  color  was  imparted  like  the  yellow  bloom  by  the  action  of  sul- 
phuric acid  added  in  the  vacuum-pan  before  discharging  the  contents  of 
the  same. 

The  composition  of  a  variety  of  raw  cane-  and  beet-sugars  is  given  in 
the  accompanying  table : 


PRODUCTS   OF   MANUFACTURE. 


153 


DESCRIPTION  OF  SUGAR. 

Sucrose. 

Glucose. 

Organic 
non- 
sugar. 

Ash. 

Water. 

Authority. 

Cane,  Cuba  'centrif.)   .  .  . 

91.90 

2.98 

2.70 

0.72 

1.70 

Wigner  and  Harland. 

Cuba  (muscovado)  . 

92.35 

3.38 

0.66 

0.77 

2.84 

Wallace. 

Jamaica       

90.40 

3.47 

1.55 

0.36 

4.22 

Wigner  and  Harland. 

Trinidad  

88.00 

5.14 

1.67 

0.96 

4.23 

Wigner  and  Harland. 

Porto  Rico 

8750 

484 

2  60 

081 

4  25 

Wigner  and  Harland 

St  Vincent  

92.50 

3.61 

2.45 

063 

0.81 

Wigner  and  Harland. 

Denierara           .   .   . 

9080 

411 

077 

1  12 

320 

Wallace. 

Benares  

94.50 

2.63 

0.39 

1.50 

0.98 

Wigner-ttnd-Harland. 

TJnclayed  Manila  .   . 

82.00 

6.79 

3.24 

2.00 

5.97 

Wigner  and  Harland. 

Concrete   

84.20 

8.45 

1.70 

1.10 

4.55 

Wallace. 

Melada  

67.00 

11.36 

1.93 

091 

18.80 

Wallace. 

Bastards              .  .   . 

6830 

1500 

120 

150 

14  00 

Wallace.                        i 

Palm,  East  Indian  

86.00 

2.19 

2.89 

2.88 

6.04 

Wigner  and  Harland. 

Beet,  First  product  .... 

94.17 

2.14 

1.48 

2.21 

Bodenbender. 

"       Second  product  .  .   . 

91.68 

2.49 

2.92 

2.91 

Bodenbender. 

2.  REFINED  SUGARS. — The  commercial  designations  of  refined  sugar 
are  very  varied.     We  may  distinguish  in  general  between  hard  sugars  and 
soft  sugars,  the  former  of  which  are  more  thoroughly  and  carefully  dried 
by  the  aid  of  artificial  heat,  while  the  latter  are  merely  centrifugated,  and 
so  retain  from  three  to  four  per  cent,  of  water  in  the  traces  of  syrup  ad- 
hering to  the  sugar.     To  the  former  class  belongs  sugar  "  crystals,"  or  sugar 
in  well-formed  individual  transparent  crystals,  which  are  as  pure  as  rock- 
candy,  as  well  as  loaf-sugar  in  the  forms  of  pulverized,  crushed,  granu- 
lated, and  cube  sugars.     To  the  latter  belong  what  are  called  grocery  sugars, 
of  which  the  finest  grades  are  called  A  sugars,  the  next  B  sugars,  and  so  on. 

In  Germany  the  finest  white-beet-sugars  are  known  as  "  rafnnade," 
inferior  grades  as  "melis"  (or  Brodzucker),  as  "pile,"  and  as  "farin,"  the 
last  of  which  is  of  inferior  grain  and  color. 

The  hard  sugars  in  general  all  show  a  sucrose  percentage  of  ninety-nine 
or  over,  while  the  soft  cane-sugars  and  the  second  grade  beet-sugars  show 
from  ninety-six  to  ninety-eight  per  cent. 

3.  MOLASSES    AND    CANE-SUGAR    SYRUPS. — The   molasses  may  be 
termed  the  mother-liquor  of  the  crystallized  product,  the  sugar.      It  is 
never  found  possible  in  practice,  however,  to  crystallize  all  the  sugar  out  or 
to  get  a  molasses  which  shall  not  contain  sucrose.     The  potash  salts,  and  in 
a  lesser  degree  the  calcium  salts,  which  are  present  in  the  crude  juice  are 
"  melassigenic," — that  is,  prevent  the  crystallization  of  a  certain  amount  of 
the  sucrose ;  the  invert  sugar,  or  glucose,  operates  in  the  same  way,  and  the 
long-continued  heating  of  the  sugar  solutions  also  has  the  effect  of  increas- 
ing the  molasses.     In  France,  for  instance,  the  rendement,  or  amount  of 
crystallized  sugar  obtainable  in  refining  of  raw  sugars,  is  calculated  by 
deducting  from  the  total  sucrose  twice  the  glucose,  and  from  three  to  five 
times  the  ash.     In  the  case  of  cane-sugars  the  ash  is  not  so  melassigenic,  not 
being  so  largely  composed  of  potassium  compounds  as  with  the  beet,  and  a 
deduction  of  one  and  a  half  times  the  glucose  is  considered  sufficient  to 
allow  for  that  impurity. 

The  experience  of  the  last  few  years  with  sorghum-sugar,  as  manu- 
factured by  the  United  States  Bureau  of  Agriculture  and  several  sorghum- 
sugar  factories  in  Kansas,  has  shown  that  this  rule  does  not  apply  to 
sorghum.  Professor  Swenson,  the  chemist  of  the  Parkinson  Company  at 
Fort  Scott,  Kansas,  finds  that  in  the  case  of  sorghum  juice  the  glucose  and 
other  solids,  known  as  "  non-sugar,"  prevent  only  two-fifths  of  their  weight 


Of  THE 

UNIVERSITY 


154 


THE   CANE-SUGAR  INDUSTRY. 


of  cane-sugar  from  crystallizing,  so  that  in  the  season  of  1887,  instead  of 
there  being  only  61.6  pounds  available  sugar  per  ton  of  cane  worked  as  the 
analyses  indicated  according  to  the  old  rule,  as  a  matter  of  fact,  130.5 
pounds  were  obtained. 

But  with  the  sugar-cane  and  the  sugar-beet  the  percentage  of  sucrose,  in 
both  the  raw  molasses  produced  in  the  extraction  of  the  sugar  from  the 
juice  and  "  refined  molasses/'  the  syrup  produced  in  the  process  of  refining 
is  quite  large.  The  composition  of  the  first,  second,  and  third  molasses  of 
the  Louisiana  cane-sugar  plantation  has  already  been  given  (see  p.  145), 
as  well  as  the  average  composition  of  beet-root  molasses.  The  following 
analysis  of  a  variety  of  molasses  will  further  illustrate  the  differences  in 
the  several  grades : 


Sucrose. 

Glucose. 

Ash. 

Organic 
non- 
sugar. 

Water. 

Authority. 

From  sugar-cane  : 
Green  syrup    

62.7 

80 

10 

06 

27.7 

Wallace. 

Golden  syrup  .... 

396 

330 

25 

28 

227 

Wallace. 

Treacle  
West  Indian  molasses    . 
Dark  molasses 

32.5 
47.0 
350 

37.2 
20.4 
100 

3.5 
2.6 
50 

3.5 
2.7 
100 

23.4 
27.3 
200 

Wallace. 
Wallace. 
J  H  Tucker. 

Fi'om  beets  : 
Beet-sugar  molasses    .  . 
Beet-sugar  molasses    .  . 
Beet-sugar  molasses    .  . 

46.7 
50.0 
55.0 

0.6 
Trace. 

13.2 
10.0 
12.0 

15.8 
20.0 
13.0 

23.7 
20.0 
20.0 

Wallace. 
Wigner  and  Harland. 
J.  H.  Tucker. 

It  will  be  seen  from  these  analyses  that  the  percentage  of  sucrose  is 
usually  much  higher  in  the  beet-root  molasses,  which  is  explained  by  the 
large  percentage  of  ash  and  organic  non-sugar.  On  the  other  hand,  the 
glucose,  or  invert  sugar,  is  large  in  the  cane-sugar  molasses,  but  almost 
entirely  wanting  in  the  beet-sugar  molasses.  The  latter,  however,  always 
contains  rqffinose,  another  variety  of  sugar  always  present  in  the  beet  juice, 
betaine,  a  nitrogenous  base,  and  proteids.  The  proportion  of  salts  con- 
tained in  beet-root  molasses  is  usually  ten  to  fourteen  per  cent.,  whereas 
refiner's  molasses  from  cane-sugar  rarely  contains  half  that  proportion. 

The  term  green  syrup,  used  above,  is  given  to  the  syrup  centrifugated 
from  the  second  products  in  the  refining  process. 

Golden  syrup  is  produced  from  a  refiner's  molasses  by  diluting,  filtering 
through  bone-black,  and  then  concentrating. 

Treacle  is  the  name  formerly  given  to  the  drainings  from  the  dark 
molasses  sugars  called  bastards.  (See  p.  152.) 

Cane-sugar  molasses,  when  refined  and  brought  to  the  condition  of 
light-colored  syrups,  forms  a  common  article  of  domestic  consumption 
under  the  general  name  of  table  syrup.  The  table  syrups  of  the  present 
day,  however,  cannot,  as  a  rule,  claim  to  be  simple  products  of  the  refining 
process,  as  they  are  almost  always  largely  admixed  with  the  cheaper  glucose 
syrup,  and  the  cane-sugar  product  in  them  is  often  entirely  replaced  by 
this  latter.  A  glucose  product,  known  as  "  mixing  syrup,"  is  quite  openly 
sold  for  this  purpose. 

Beet-sugar  molasses  is  not  adapted  for  use  as  table  syrup  on  account  of 
the  unpleasant  taste  and  odor,  due  to  the  nitrogenous  principles  present. 
It  is,  as  before  described,  worked  for  the  extraction  of  the  sugar,  or  it  is 
fermented  for  alcohol. 

4.  MISCELLANEOUS  SIDE-PKODUCTS. — (1)  Exhausted  Residue  from  the 


PEODUCTS  OF  MANUFACTUEE.  155 

Sugar-cane  or  Sugar-beet. — The  character  of  this  residue  differs  very  greatly 
according  to  the  method  of  juice  extraction  which  has  been  followed.  The 
common  sugar-cane  residue  from  the  roll-mills,  known  as  "  bagasse,"  con- 
sists of  the  fibre  and  cellular  material  of  the  cane  still  enclosing  some  six 
per  cent,  of  sucrose,  or  about  one-third  of  the  total  eighteen  per  cent,  which 
the  fresh-cut  cane  contains.  It  is  very  largely  used  as  fuel  on  the  sugar 
plantations,  and  the  ash  serves  to  some  extent  as  fertilizing  material  for  the 
soil.  The  cane-fibre,  when  freed  more  fully  from  the  sugar  by  the  diffusion 
process,  has  been  proposed  as  a  source  of  paper-stock.  (See  p.  128^  • 

Both  the  pressed  pulp  and  the  exhausted  diffusion-chips  from  the  sugar- 
beet  are  recognized  as  valuable  cattle  food.  Marcker  found  in  the  dried 
press-cake  1.227  per  cent,  of  nitrogen.  The  exhausted  chips  of  the  diffusion- 
cells  are  still  richer  in  nitrogen,  as  the  diffusion  process  does  not  extract  as 
much  nitrogenous  matter  as  the  method  of  crushing. 

(2)  Scums  and  Saturation  Press-cakes. — In  describing  the  production  of 
raw  cane-sugar  mention  was  made  of  the  scums,  which  had  at  one  time  been 
thrown  away,  but  which  when  filter-pressed  yielded  a  very  considerable 
additional  amount  of  sugar.     The  press-cake  obtained  in  this  treatment 
has  also  a  value.     It  contains  on  an  average  as  taken  from  the  press  45.17 
per  cent,  of  water,  15.67  per  cent,  of  ash,  3.49  per  cent,  of  phosphoric  anhy- 
dride, and  1.14  per  cent,  of  nitrogen,  or,  reckoned  on  the  dry  material,  28.56 
per  cent,  of  ash,  6.33  per  cent,  of  phosphoric  anhydride,  and  2.10  per  cent, 
of  nitrogen.     Its  value,  as  taken  from  the  press,  at  the  ruling  rates  for  fer- 
tilizing materials,  would  be  $10.64  per  ton.*     Where  the  carbonatation 
process  is  used,  and  the  excess  of  lime   removed  by  carbon  dioxide,  the 
scums  and  carbonate  of  lime  are  found  together  in  the  press-cake  gotten 
by  filtering.     In  the  experimental  tests  of  the  carbonatation  process  as  ap- 
plied to  cane-sugar  made  by  the  United  States  Department  of  Agriculture  at 
Fort  Scott,  Kansas,  in  1886,f  the  press-cake  obtained  after  saturation  and 
filtering  when  dried  was  found  to  contain  9.585  per  cent,  of  albuminoids 
and  17.45  per  cent,  of  other  organic  matter.     The  saturation  press-cake  of 
the  beet-sugar  process  does  not  contain  so  high  a  percentage  of  albuminoids, 
but  a  much  larger  amount  of  nitrogenous  compounds  remains  in  the  clari- 
fied juice,  giving  rise  to  the  escape  of  ammonia  on  concentration  in  the  vacuum- 
pan  and  showing  itself  in  the  molasses. 

(3)  Exhausted  Bone-black. — The  bone-black  after  repeated  revivifying 
(see  p.  150)  becomes  at  last  valueless  for  filtration  purposes  and  passes  out 
of  the  sugar-refinery,  going  to  the  manufacturer  of  fertilizers,  for  whom  it  is 
a  very  valuable  material.     The  more  calcium  phosphate  and  the  less  calcium 
carbonate  it  contains,  the  more  valuable  it  is  for  superphosphate  manufac- 
ture, as,  on  the  addition  of  sulphuric  acid,  the  liberated  phosphoric  acid  re- 
mains, adding  to  the  value  of  the  product,  while  the  carbonic  acid  is  driven 
off.     The  exhausted  bone-black  contains  on  an  average  thirteen  per  cent,  of 
calcium  carbonate,  sixty  to  seventy-four  per  cent,  of  calcium  phosphate,  four 
per  cent,  of  carbon,  and  four-tenths  to  six-tenths  per  cent,  of  nitrogen. 

(4)  Vinasse,  or  Molasses  Residues. — When  the  beet  molasses  is  fermented 
for  the  production  of  alcohol,  the  residual  liquor,  which  contains  all  the 
potash  salts  of  the  molasses,  is  known  in  French  as  "  vinasse,"  or  in  German 
as  "  schlempe."     It  is  of  about  41  °  B.  and  acid  in  reaction.     It  is  neutral- 

*  Bulletin  of  Department  of  Agriculture,  No.  11,  p.  16. 
f  Ibid.,  No.  14,  p.  54. 


156  THE   CANE-SUGAR   INDUSTRY. 

ized  with  calcium  carbonate  and  then  evaporated  down  to  dry  ness  and  cal- 
cined. The  black  porous  residue  so  obtained  contains  thirty  to  thirty-five 
per  cent,  of  potassium  carbonate,  eighteen  to  twenty  per  cent,  of  sodium 
carbonate,  eighteen  to  twenty-two  per  cent,  of  potassium  chloride,  six  to 
eight  per  cent,  of  potassium  sulphate,  and  fifteen  to  twenty-eight  per  cent, 
of  insoluble  matter.  It  is  exhausted  with  hot  water,  and  the  extract  evap- 
orated down,  when  potassium  sulphate  and  afterwards  sodium  carbonate 
separate  out.  On  cooling,  potassium  chloride  and  potassium  sulphate  crys- 
tallize out,  and  the  mother-liquor  contains  potassium  carbonate  admixed  with 
some  sodium  carbonate.  It  is  possible  by  this  gradual  evaporation  and 
fractional  crystallization  to  bring  the  crude  potashes  to  a  purity  of  ninety 
per  cent.  In  this  production  of  the  solid  potashes  from  the  molasses  residue 
all  the  nitrogen  of  the  molasses  is  lost.  To  prevent  this,  C.  Vincent,  a 
French  chemist,  has  proposed  to  submit  the  evaporated  vinasse  to  a  dry 
distillation  instead  of  calcination  in  the  air.  The  residue  of  this  distillation 
is  an  open  and  very  porous  coke  containing  all  the  mineral  salts  of  the 
molasses,  which  can  then  be  extracted  as  before.  The  products  of  distilla- 
tion are  an  illuminating  and  heating  gas,  ammonia  water,  and  a  small 
amount  of  tar.  The  ammonia  water  is  the  most  interesting  product. 
It  contains  besides  carbonate,  sulphide  and  cyanide  of  ammonium,  methyl 
alcohol,  and  notable  quantities  of  trimethylamine.  This  latter  can  be  de- 
composed at  320°  C.  by  dry  hydrochloric  acid  gas  into  methyl  chloride  and 
ammonia,  and  on  passing  the  products  through  aqueous  hydrochloric  acid,  the 
methyl  chloride  goes  through  unabsorbed,  while  the  ammonia  is  taken  up. 
The  methyl  chloride  is  of  great  value  for  ice  machines  and  for  the  manu- 
facture of  methylated  aniline  colors.  (See  p.  412.)  The  process  was  quite 
largely  introduced,  but  as  in  recent  years  the  molasses  is  worked  over  for 
sugar  in  increasing  amounts,  less  molasses  is  fermented,  and  hence  less  vinasse 
is  obtained. 

IV.  Analytical  Tests  and  Methods. 

1.  DETERMINATION  OF  SUCROSE. — (A)  Optical  Methods. — Among  the 
most  important  physical  properties  of  many  of  the  varieties  of  sugars  is  the 
power  possessed  by  their  solutions  of  rotating  the  plane  of  polarization  to  the 
right  or  the  left.  They  are  accordingly  classified  as  dextro-rotatory,  laevo- 
rotatory,  or  optically  inactive  in  case  no  power  of  circular  polarization  is 
manifested.  This  property  as  possessed  by  solutions  of  cane-sugar,  of 
deviating  the  polarized  ray  in  a  fixed  and  definite  degree,  has  been  made 
the  basis  of  the  method  of  analysis  by  means  of  polariscopes.  The  funda- 
mental idea  involved  in  these  instruments  is  to  compensate  for  and  so  de- 
termine the  optical  rotatory  power  of  sugar  solutions  of  unknown  strength 
by  the  corresponding  circular  polarizing  action  of  quartz  plates  of  known 
thickness,  and  hence  of  known  power.  The  earliest  of  polariscopes  was 
the  Mitscherlich  instrument,  but  those  now  in  use  for  sugar  analysis  are 
either  the  Soleil-Ventzke-Scheibler,  the  Soleil-Dubosq,  the  Laurent  shadow 
instrument,  or  the  Schmidt  and  Haensch,  which  last  claims  to  combine  the 
best  features  of  the  Soleil  and  the  Laurent  instruments.  A  general  view 
and  a  longitudinal  section  of  this  instrument  is  given  in  Fig.  54.  The 
glass  tube  containing  the  sugar  solution  is  shown  lying  in  the  axis  of  the  tele- 
scope and  the  polarizing  prisms.  To  the  right  below  is  shown  the  polar- 
izing prism  (the  so-called  Jellet-Cornu  prism),  to  the  left  is  the  analyzing 
prism,  a  quartz  plate,  quartz  wedges  of  opposite  rotatory  power,  and  the  lenses 


ANALYTICAL   TESTS   AND   METHODS. 


157 


of  the  telescope,  with  a  plate  of  bichromate  of  potash  to  correct  for  any 
color  in  the  field.  In  this  instrument,  which  uses  white  light,  the  field  of 
view  is  a  circle,  which,  with  the  instrument  at  0°  and  nothing  intercepting 
the  light,  is  of  a  uniform  gray  tint.  When  a  sugar  solution  is  interposed, 
one-half  of  the  circle  becomes  darker  than  the  other,  and  the  quartz  wedges, 
controlled  by  the  screw  shown  underneath,  must  be  moved  to  compensate  for 
the  rotation  due  to  the  sugar  solution  and  to  restore  the  uniformity  of  tint.  The 
instrument  is  so  graduated  that  one  degree  of  displacement  on  the  scale  corre- 
sponds to  .26048  gramme  of  cane-sugar  dissolved  in  100  cubic  centimetres 
of  water  and  viewed  through  a  200-millimetre  tube.  Therefore  26.048 
grammes  of  the  sugar  to  be  analyzed  are  weighed  out.  If  chemically  pure 
and  anhydrous,  the  solution  of  the  strength  stated  should  read  one  hundred 

FIG.  54. 


DZX7 


degrees  of  displacement,  or  one  hundred  per  cent,  of  sugar,  and  if  impure, 
correspondingly  less. 

In  the  application  of  polariscope  analysis  to  cane-sugars  two  cases  may 
arise  :  first,  when  no  other  optically  active  substance  is  present,  and,  second, 
when  glucose  or  invert  sugar  is  also  present. 

(a)  Absence  of  other  Optically  Active  Substances. — The  weighed  sample  is 
dissolved  in  about  fifty  cubic  centimetres  of  water  in  a  flask  marked  for  one 
hundred  cubic  centimetres.  As  soon  as  the  sugar  is  all  dissolved,  a  few  cubic 
centimetres  of  a  solution  of  basic  acetate  of  lead  are  added,  and  two  or  three 
cubic  centimetres  of  cream  of  hydrated  alumina.  The  liquid  is  well  agitated, 
and  then  the  flask  is  filled  nearly  to  the  mark  on  the  neck  with  water  and 
the  froth  allowed  to  rise  to  the  surface,  when  it  is  flattened  by  the  addition 
of  a  drop  of  ether.  Water  is  now  added  exactly  to  the  mark,  the  contents 
of  the  flask  thoroughly  agitated,  and  the  liquid  filtered  through  a  dry 
filter.  In  the  case  of  very  dark  sugars,  purified  and  perfectly  dry  bone- 


158  THE   CANE-SUGAR  INDUSTRY. 

black  has  been  added  for  clarifying  purposes.  However,  it  is  generally 
acknowledged  to  introduce  error  by  its  absorption  of  small  amounts  of 
sugar,  so  that  it  is  now  dispensed  with,  or  if  used  on  the  dry  filter,  the  first 
third  of  the  filtrate  is  rejected  and  the  later  portions  only  used.  Allen  * 
recommends  instead  the  use  of  a  ten  per  cent,  solution  of  sodium  sulphite. 
The  tube  of  the  polariscope  is  now  rinsed  with  the  clear  sugar  solution 
and  then  filled  with  the  same,  the  open  end  closed  with  a  smooth  glass 
plate  held  in  place  by  a  brass  cap,  which  is  screwed  on.  The  tube  con- 
taining the  sugar  solution  is  then  placed  in  the  instrument,  and  the  lower 
thumb-screw  turned  uotil  the  uniformity  of  shade  in  the  two  halves  of 
the  field  is  restored,  when  the  number  of  degrees  (or  percentage  of  cane- 
sugar  in  the  sample)  is  read  off  on  the  scale. 

(6)  Presence  of  Glucose,  Invert  Sugar,  or  other  Optically  Active  Substance. 
— The  action  of  acids  upon  cane-sugar  has  already  been  stated  to  cause  in- 
version,— i.e.,  change  of  the  sucrose  into  dextrose  and  levulose.  Both  these 
varieties  of  sugars  differ  from  sucrose  in  their  optical  power.  If,  then,  these 
alteration  products  accompany  the  sucrose  in  a  cane-sugar  sample,  the  results 
of  the  polariscope  reading  may  be  vitiated.  Some  writers  have  held  that 
the  invert  sugar  present  in  raw  cane-sugars  and  syrups  is  optically  inactive, 
but  the  statement  seems  to  have  been  disproved  by  Meissl.  Besides,  in 
raw  beet-sugars  and  syrups,  raffinose,  a  very  strong  dextro-rotatory  sugar,  is 
found  vitiating  the  readings  for  cane-sugar.  The  correction  of  the  original 
polarization  in  such  cases  is  most  generally  made  by  the  method  of  inver- 
sion proposed  by  Clerget.  The  direct  polarization  is  taken  in  the  usual  way, 
and  a  part  of  the  solution  remaining  from  the  one  hundred  cubic  centimetres 
prepared  for  this  test  is  put  into  a  50-cubic-centimetre  flask,  which  has  also 
a  55-cubic-centimetre  mark  on  the  neck.  Fifty  cubic  centimetres  having 
been  taken,  five  cubic  centimetres  of  concentrated  hydrochloric  acid  is  added, 
and  the  whole  heated  on  a  water-bath  to  70°  C.  for  some  ten  minutes.  This 
suffices  to  completely  invert  the  cane-sugar  present,  while  the  original  invert 
sugar  is  unacted  on.  The  flask  is  then  cooled,  and  part  of  the  liquid  is 
filled  into  a  220-millimetre  tube,  closed  by  glass  plates  at  both  ends  and 
provided  with  a  tubulure  in  the  side  so  that  a  thermometer  may  hang 
suspended  in  the  liquid  when  the  observation  is  made.  The  reading  will 
generally  be  much  reduced  from  the  original  dextro-rotatory  reading,  and 
may  even  be  some  degrees  to  the  left.  If,  then,  S  represent  the  sum  or 
difference  of  polariscope  readings  before  and  after  inversion  (difference  if 
both  are  to  the  right,  sum  if  the  second  reading  is  to  the  left),  T  the 
temperature  of  the  inverted  solution  when  polarized,  and  R  the  correct 

200  Sf 
percentage  sought,  R  =  .     Clerget  has  also  prepared  an  elaborate 

285 — -/ 

set  of  tables  which  make  the  use  of  the  formula  unnecessary.  (See  also 
under  molasses,  p.  162.) 

(JB)  Chemical  Methods. — The  only  chemical  method  for  the  determination 
of  cane-sugar  ever  resorted  to  is  the  inversion  of  the  cane-sugar,  neutralizing 
with  sodium  carbonate,  and  determination  of  the  reducing  sugar  so  obtained 
by  the  method  to  be  described  under  the  next  head.  The  inversion  takes 
place  in  definite  proportions,  so  that  nineteen  parts  of  sucrose  produce  twenty 
parts  of  the  invert  sugar.  When  invert  sugar  is  also  present  in  the  solution 


*  Commercial  Organic  Analysis,  3d  ed.,  vol.  i.  p.  257. 


ANALYTICAL   TESTS   AND   METHODS.  159 

of  which  the  cane-sugar  is  to  be  determined  by  inversion,  the  former  is  first 
estimated  as  a  separate  operation,  and  then  a  portion  of  the  original  solution 
is  inverted,  and  the  total  invert  sugar,  including  that  formed  from  the  cane- 
sugar,  is  determined. 

2.  DETERMINATION  OF  GLUCOSE,  OR  INVERT  SUGAR. — The  oldest 
method  is  that  based  on  Trommer's  reaction  as  applied  to  sugar  analysis  by 
Barreswill  and  Fehling.  This  depends  upon  the  fact  that  an  alkaline  solu- 
tion of  copper  oxide  containing  a  fixed  organic  acid,  as  tartaric,  is  reduced 
with  the  separation  out  of  insoluble  cuprous  oxide  by  dextrose,  or  invert 
sugar,  while  cane-sugar  has  no  effect.  The  composition  of  a  standard 
Fehling's  solution,  as  it  is  called,  is  thus  given  by  Tollens :  *  34.639 
grammes  crystallized  copper  sulphate  are  dissolved  in  water  and  brought  to 
500  cubic  centimetres  ;  173  grammes  Rochelle  salt  and  60  grammes  sodium 
hydrate  are  also  dissolved  in  water  and  brought  to  500  cubic  centimetres. 
Equal  volumes  of  these  solutions  are  mixed  when  required  for  use  and  con- 
stitute the  correct  Fehling's  solution.  The  ready-prepared  Fehling's  solution 
changes  in  the  course  of  some  days  in  effective  power  even  when  kept  in  a 
cool  place  and  in  the  dark.  Ten  cubic  centimetres  of  the  Fehling's  solution 
given  above  correspond  to  .05  gramme  dextrose,  or  invert  sugar,  or  .0475 
gramme  cane-sugar  made  active  by  inversion.  For  technical  determinations 
merely  the  work  with  the  solution  can  be  volumetric ;  for  more  exact  scien- 
tific purposes  it  must  be  gravimetric,  weighing  the  copper  as  metal  or  as 
cupric  oxide.  In  carrying  out  the  volumetric  test,  the  sugar  solution  in 
which  glucose  is  to  be  determined  is  placed  in  a  burette.  If  dark,  it  may 
be  previously  cleared  with  a  small  quantity  of  bone-black,  or  if  it  be  some 
of  the  solution  prepared  for  polarization,  it  is  prepared  without  lead  solu- 
tion, an  aliquot  portion  taken  out  for  this  glucose  determination,  and  the 
remainder  treated  with  a  measured  quantity  of  the  lead  solution,  for  which 
allowance  is  made.  Any  lead  in  this  glucose  solution  must  be  eliminated 
thoroughly.  This  is  best  done  with  sulphurous  acid,  the  change  of  strength 
in  the  liquid  being  noted.  Ten  cubic  centimetres  of  the  mixed  Fehling's 
solution  are  now  measured  into  a  porcelain  dish,  diluted  with  twenty  or 
thirty  cubic  centimetres  of  water  and  brought  quickly  to  boiling,  when  the 
sugar  solution  is  run  in  two  cubic  centimetres  at  a  time,  boiling  between 
each  addition.  When  the  blue  color  has  nearly  disappeared  the  sugar 
solution  should  be  added,  in  small  amount  but  still  rapidly.  The  end  of 
the  reaction  is  reached  when  a  few  drops  of  the  supernatant  liquid  filtered 
into  a  mixture  of  acetic  acid  and  dilute  potassium  ferrocyanide  give  no  brown 
color. 

In  carrying  out  the  gravimetric  method  the  Fehling's  solution  remains 
in  excess,  while  the  precipitated  cuprous  oxide  is  carefully  filtered  off  and 
further  treated.  The  procedure  is  as  follows  :  Sixty  cubic  centimetres  of 
the  mixed  Fehling's  solution  and  thirty  cubic  centimetres  of  water  are  boiled 
up  in  a  beaker  glass,  twenty-five  cubic  centimetres  of  the  dextrose  solution 
of  approximately  one  per  cent,  strength  added,  and  the  mixture  again  boiled. 
It  is  then  filtered  with  the  aid  of  a  filter-pump  upon  a  Soxhlet  filter  (as- 
bestos layer  in  a  tared  funnel  of  narrow  cylinder  shape),  quickly  washed 
with  hot  water,  and  then  with  alcohol  and  ether,  and  dried.  The  as- 
bestos filter,  with  the  cuprous  oxide,  are  now  heated  with  a  small  flame, 
while  a  current  of  hydrogen  is  passed  into  the  funnel,  so  that  the  precipitate 

*  Handbuch  der  Kohlenhydrate,  1888,  p.  71. 


160  THE   CANE-SUGAE   INDUSTRY. 

is  reduced  to  metallic  copper.  It  is  allowed  to  cool  in  the  current  of  hydro- 
gen, placed  for  a  few  minutes  over  sulphuric  acid,  and  then  weighed.  A 
table  has  been  constructed  by  Allihn  which  gives  in  milligrammes  the 
dextrose  corresponding  to  the  weight  of  copper  found. 

Other  methods  for  the  determination  of  dextrose  are  those  of  Pavy, 
using  an  ammoniacal  solution  of  the  Fehling  reagent ;  of  Knapp,  who  uses 
an  alkaline  solution  of  cyanide  of  mercury ;  of  Sachsse,  who  uses  an  alkaline 
solution  of  potassio-mercuric  iodide ;  and  of  Soldaini,  who  uses  a  solution 
of  basic  carbonate  of  copper  dissolved  in  potassium  bicarbonate.  This  last 
reagent  has  been  recently  strongly  commended  as  better  than  Fehling's 
solution,  in  that  it  is  more  sensitive  to  glucose  and  is  much  less  affected  by 
cane-sugar  even  after  prolonged  boiling.* 

3.  ANALYSIS  OF  COMMERCIAL  RAW  SUGARS. — Eaw  sugars  contain, 
besides  the  cane-sugar,  invert  sugar,  moisture,  mineral  salts,  organic  non- 
sugar,  and  insoluble  matter.  Raw  beet-sugars  contain,  in  addition  to  the 
sucrose  and  glucose  just  mentioned,  small  quantities  of  raffinose,  a  variety 
of  sugar  found  in  the  beet  juice  and  present  in  all  the  products  from  it. 

The  cane-sugar  present  is  partly  crystallized  and  partly  uncrystallizable. 
Both  are,  of  course,  counted  together  in  the  polarization  figures,  but  only  the 
first  is  capable  of  extraction  in  the  refining  process.  The  method  of  esti- 
mating the  crystallized  cane-sugar  for  itself  will  be  described  later  on.  The 
polarization  methods  have  already  been  described.  In  raw  sugars  containing 
much  invert  sugar,  such  as  those  from  the  cane,  the  double  polarization  (be- 
fore and  after  inversion)  is  alone  to  be  relied  upon. 

The  methods  for  glucose  have  also  been  described. 

The  determination  of  moisture  is  made  by  taking  five  grammes  of  the 
sample  and  drying  it  spread  out  on  a  weighed  watch-crystal  in  an  air-bath 
at  100°  to  110°  C.  until  it  ceases  to  lose  weight.  As  sugars  containing  much 
glucose  cannot  stand  the  heat  without  some  alteration,  in  their  case  a  lower 
temperature  (60°  to  90°  C.)  is  used.  For  very  syrupy  sugars  and  melados 
it  becomes  necessary  to  dry  with  the  addition  of  a  weighed  amount  of 
clean  sand.  Drying  in  a  vacuum  is  also  practised  in  many  cases,  as  the 
operation  is  shortened  and  less  risk  of  alteration  exists. 

The  mineral  salts  are  determined  as  ash.  The  following  analyses  give 
the  average  composition  of  raw  cane-  and  beet-sugar  ash  according  to  Monier  : 

Cane-sugar.  Beet-sugar. 

Potassium  (and  sodium)  carbonate 16.5  82.2 

Calcium  carbonate 49.0  6.7 

Potassium  (and  sodium)  sulphate 16.0  \  -,  -,  -, 

Sodium  chloride 9.0  | 

Silica  and  alumina 9.5  None. 

1000  100.0 

Owing  to  this  decided  difference,  it  is  much  easier  to  get  the  ash  of  cane- 
sugars  completely  burned  and  in  weighable  condition  than  that  of  beet- 
sugars,  which  contain  so  much  of  the  deliquescent  and  alkaline  carbonates. 
To  obviate  this  difficulty,  Scheibler  proposes  to  treat  the  sugar  with  sulphuric 
acid  before  igniting  it,  by  which  means  the  ash  obtained  contains  the  bases 
as  non-volatile,  difficultly  fusible  and  non-deliquescent  sulphates  instead  of 
as  carbonates.  A  deduction  of  one-tenth  of  the  weight  of  the  sulphated 
ash  must  be  made  in  this  case  for  the  increase  due  to  the  sulphuric  acid, 

*  Bodenbender  and  Scheller,  Zeitschrift  fur  Riibenzucker,  1887,  p.  138 


ANALYTICAL  TESTS   AND   METHODS.  161 

The  soluble  and  insoluble  ash  are  often  distinguished  in  addition  to  total 
ash.  In  ordinary  commercial  analyses  of  sugars,  the  sum  of  the  cane-sugar, 
glucose,  ash,  and  water  is  subtracted  from  one  hundred,  and  the  difference 
called  organic  or  undetermined  matters.  This  would  include  both  the  solu- 
ble organic  impurities  and  the  insoluble  impurities,  such  as  fibre  and  parti- 
cles of  cane.  Two  processes  have  been  proposed  for  determining  the  solu- 
ble organic  impurities  separately  :  Walkoff's  method  of  precipitation  with 
tannin,  and  the  basic  acetate  of  lead  method.  Neither  method  is  in  very 
general  use. 

As  before  stated,  the  full  analysis  of  a  raw  sugar  will  not  give  any 
exact  measure  of  its  refining  value, — that  is,  of  the  amount  of  crystallized 
cane-sugar  that  can  be  extracted  from  it.  The  so-called  method  of  co- 
efficients adopted  in  France,  whereby  five  times  the  ash,  plus  once  or  twice 
the  glucose  percentage  subtracted  from  the  cane-sugar  percentage,  is  taken 
to  represent  the  crystallized  cane-sugar  obtainable,  is  not  much  to  be 
depended  upon.  The  true  refining  value,  or  rendement,  of  a  raw  sugar  can, 
however,  be  determined  by  a  special  procedure  first  proposed  by  Payeh 
and  afterwards  improved  by  Scheibler.  The  process  depends  upon  the  fact 
that  if  raw  sugars  be  treated  with  a  saturated  alcoholic  solution  of  cane- 
sugar  acidified  with  acetic  acid,  the  coloring  matter  and  other  impurities, 
together  with  the  syrup  and  other  uncrystallizable  constituents,  are  removed, 
while  the  crystallized  sugar  remains  unchanged.  The  sugary  alcoholic 
liquids  are  then  displaced  by  absolute  alcohol.  Fig.  55  shows  the  arrange- 
ment of  vessels.  The  bottle  I  contains  eighty-five  per  cent,  alcohol,  to 
which  50  cubic  centimetres  of  acetic  acid  is  added  per  litre,  and  the  mixture 
allowed  to  stand  in  contact  with  an  excess  of  powdered  white  sugar  for  a 
day,  being  shaken  at  intervals ;  bottle  II,  alcohol  of  ninety-two  per  cent, 
saturated  as  the  other,  but  without  acetic  acid  ;  bottle  III,  alcohol  of  ninety- 
six  per  cent.,  also  saturated  with  sugar;  and  bottle  IV,  a  mixture  of  two- 
thirds  absolute  alcohol  and  one-third  ether.  Of  the  sugars  to  be  examined, 
weights  are  taken  corresponding  to  the  polariscope  used,  placed  in  the  up- 
right tubes,  washed  with  the  successive  solutions,  and  dried  by  the  aid  of 
a  filter-pump  ready  for  use  in  the  polariscope  test.  In  carrying  out  the 
process,  the  alcohol  and  ether  mixture  is  first  run  in  that  it  may  take  up 
any  moisture  and  throw  out  the  sugar  that  such  moisture  may  have  dis- 
solved, then  successively  down  to  No.  I,  which  is  the  effective  washing 
solution.  This  is  then  displaced  by  Nos.  II,  III,  and  IV  in  succession. 
The  method  is  thoroughly  reliable,  but  great  care  must  be  taken  to  keep 
the  alcoholic  solutions  just  saturated  with  sugar  through  all  changes  of 
temperature. 

4.  ANALYSES  OF  MOLASSES  AND  SYRUPS. — The  composition  of  both 
the  cane-sugar  and  the  beet-sugar  molasses  have  already  been  given  (see  p. 
1 54),  and  it  was  seen  that  they  differed  notably.  Both  still  contain  con- 
siderable quantities  of  sucrose,  but  for  different  reasons.  With  the  cane- 
sugar  molasses  because  of  the  invert  sugar,  with  the  beet-sugar  molasses 
because  of  the  melassigenic  salts.  In  either  case  the  polariscope  reading 
for  sucrose  must  be  corrected  by  inversion.  The  glucose  is  determined  as 
described  under  raw  sugars.  The  water  is  determined  by  weighing  out  a 
sample,  thinning  it  with  water,  putting  it  into  a  weighed  dish  with  clean 
sand,  and  drying  it  at  a  temperature  of  60°  C.  until  constant.  Drying  in 
a  partial  vacuum  also  facilitates  the  drying  off  of  the  moisture.  The  ash 
is  determined  as  with  raw  sugars,  sulphuric  acid  being  added,  and  the  bases 

11 


162 


THE   CANE-SUGAR   INDUSTEY. 


Weighed  as  sulphates  instead  of  as  carbonates,  the  proper  correction  being 
made.  The  organic  non-sugar  is  simply  taken  by  difference  as  with  raw 
sugars.  The  determination  of  raffinose  in  raw  beet-sugars,  and  particularly 
in  beet-molasses,  has  attracted  much  attention  in  recent  years.  Creydt* 
has  suggested  a  way  for  determining  it  in  the  presence  of  cane-sugar  in  con- 
nection with  the  method  of  inversion.  He  finds  that  while  cane-sugar 
polarizing  100°  to  the  right  before  inversion  polarizes  32°  to  the  left 
after  inversion,  a  change  of  132°,  raffinose  changes  from  100°  to  50.7° 

FIG.  55. 


only,  a  change  of  49.3°.  He  proposes  two  formulas  :  -4  =  2  +  1.57  R,  and 
c=  1.322  +  1.57  R  X  .493,  in  which  A  is  the  direct  polarization,  c  the 
polarization  after  inversion,  z  the  percentage  of  cane-sugar,  and  JR  that  of 
raffinose.  From  these  formulas,  A  and  c  being  known,  z  and  It  can  be 
found.  The  reading  after  inversion  must  be  taken  uniformly  at  20°  C. 

5.  ANALYSES    OF    SUGAR-CANES    AND    SUGAR-BEETS    AND    RAW 
JUICES  THEREFROM. — The  very  different  physical  characters  of  the  sugar- 

*  Zeitschrift  fur  Kubenzucker,  vol.  xxxvii.  p.  163. 


ANALYTICAL   TESTS   AND    METHODS.  163 

cane  and  the  sugar-beet,  the  one  a  bamboo-like  shell  enclosing  a  woody  pith, 
and  the  other  a  soft  root  easily  brought  into  pulpy  consistency,  make  the 
work  upon  them  quite  different.  In  the  case  of  the  cane,  the  samples  to 
be  analyzed  are  weighed  and  then  pressed  between  rolls,  moistened  with 
hot  water  and  again  pressed,  and  this  repeated  several  times.  The  ex- 
hausted stalk,  or  "  bagasse,"  is  usually  not  further  examined,  but  in  the  juice 
the  sucrose,  glucose,  ash,  and  organic  non-sugar  are  determined  as  before 
described.  In  all  analyses  of  raw  cane  juices  the  percentage  of  total  solids 
is  determined  by  the  Brix  saccharometer  or  "spindle."  The  form  of 
hydrometer  in  most  general  use  is  known  as  the  Balling  or  Brix,  and  its 
readings  indicate  directly  the  percentage  of  impure  sugar  or  solid  matter 
dissolved.  Sets  of  tables  also  allow  of  the  conversion  of  the  Brix  scale 
into  direct  specific  gravity  figures.  (See  Appendix,  p.  51 5.)  With  the  aid  of 
the  specific  gravity  determination  it  is  possible  to  make  a  rapid  analysis  of 
raw  juice  without  weighing.  The  method  adopted  by  Crampton,*  one  of 
the  chemists  of  the  United  States  Bureau  of  Agriculture,  for  this  analysis 
is  to  measure  out  a  certain  volume  of  the  juice,  add  lead  solution,  make  up 
to  another  definite  volume,  polarize,  and  apply  the  correction  for  specific 
gravity  to  the  reading  obtained.  A  set  of  tables  for  this  correction  and  the 
factor  needed  in  the  glucose  determination  are  given  by  Crampton. 

In  the  examination  of  sugar-beets,  the  system  of  pressing  and  moisten- 
ing with  hot  water  can  be  followed  for  the  extraction  of  the  juice,  but  the 
method  proposed  by  Scheibler  of  extracting  the  sugar  from  a  weighed 
quantity  of  the  pulp  by  the  aid  of  alcohol  is  much  better.  This  is 
accomplished  by  the  aid  of  a  Soxhlet  or  other  extractor  (see  p.  78)  con- 
nected with  an  upright  condenser.  After  complete  extraction  and  cooling 
the  necessary  amount  of  lead  solution  is  added,  and  the  liquid  brought  up 
to  the  mark  with  absolute  alcohol  and  then  polarized.  Degener  has  de- 
scribed a  still  simpler  form  of  extraction,  originally  suggested  by  Rapp,  in 
which  the  pulp  remains  in  the  alcoholic  solution  until  after  it  is  cleared 
with  the  lead  solution  and  brought  to  the  mark,  when  it  is  filtered  and 
polarized.  A  correction  must  in  this  case  be  applied  to  the  reading  on 
account  of  the  volume  occupied  by  the  pulp  in  the  measured  liquid. 

The  amount  of  dry  residue,  or  "  mark,"  of  the  beet  can  be  determined 
in  the  Scheibler  extraction  method  at  the  same  time  by  taking  the  exhausted 
residue,  drying  it  in  a  current  of  air,  and  weighing  it.  The  moisture  and 
ash  of  the  beet  are  determined  as  with  raw  sugars.  The  organic  non-sugar 
is  gotten  by  difference  or  by  one  of  the  methods  mentioned  under  raw  sugars 

6.  ANALYSES  OF  SIDE-PRODUCTS. — (a)  Of  Bone-black. — Careful  anal- 
yses of  both  fresh  char  and  that  which  is  in  use  are  needed  to  allow  of  the 
proper  control  in  filtration.  The  most  important  determinations  are  those 
of  water,  carbonate  of  lime,  carbon,  and  specific  gravity,  as  upon  the  changes 
in  these  depend  in  the  main  its  efficiency.  The  water  is  determined  by  dry- 
ing for  several  hours  at  140°  C.  The  sample  should  not  be  powdered. 
The  carbon  is  determined  by  treating  a  weighed  quantity  of  the  char  with 
pure  hydrochloric  acid,  with  the  aid  of  heat,  on  a  water-bath  until  the  soluble 
portions  have  been  dissolved,  diluting  and  filtering  upon  a  weighed  quanti- 
tative filter.  After  thorough  washing  with  hot  water,  the  filter  and  contents 
are  dried  at  100°,  placed  between  watch-glasses  and  weighed,  again  heated 
and  weighed  as  long  as  any  loss  of  weight  is  shown.  The  filter  and  carbon 

*  United  States  Bureau  of  Agriculture,  Bulletin  No.  15,  pp.  31-35. 


164  THE   CANE-SUGAR   INDUSTRY. 

are  then  transferred  to  a  weighed  crucible  and  ignited.  The  insoluble  resi- 
due, taken  from  the  previous  weight,  minus  the  weight  of  the  filter,  gives 
the  amount  of  carbon.  The  estimation  of  carbonate  of  lime  in  case  the 
char  is  used  with  cane-sugar  or  juices  is  of  much  less  importance  than  when 
the  char  is  used  with  beet-sugars  or  juices.  In  the  former  case,  the  per- 
centage decreases  at  first,  and  then  remains  nearly  stationary,  in  the  repeated 
use  of  the  char,  while  in  the  latter  case  it  would  increase  steadily,  because  of 
the  more  thorough  liming  and  carbonatation  to  which  the  beet  juices  are 
subjected,  were  it  not  for  the  treatment  with  hydrochloric  acid  in  the  revivi- 
fying of  the  char.  (See  p.  150.)  To  allow  of  the  proper  judgment  in  this 
use  of  hydrochloric  acid,  it  becomes  necessary  in  beet-sugar  working  to 
determine  carefully  the  amount  of  carbonate  of  lime  taken  up  by  the  char 
in  using  before  starting  the  revivification.  It  is  almost  universally  done  at 
present  by  the  aid  of  the  Scheibler  apparatus,  shown  in  Fig.  56.  The  nor- 
mal quantity  of  pulverized  char  (1.702  grammes)  is  placed  in  A,  and  the 
tube  8  filled  with  acid  to  the  mark  is  carefully  placed  in  the  bottle.  E  is 
then  filled  with  water,  and  the  operator,  by  means  of  the  compression-bulb, 
forces  the  liquid  into  D  and  (7,  which  connect  at  the  base,  until  it  reaches  a 
little  above  the  zero-point  in  CJ  when  it  is  allowed  to  flow  out  by  opening 
the  pinchcock  at  p  until  the  level  in  C  is  at  zero.  The  stopper  now  being 
placed  in  A,  a  connection  with  B  is  made  by  the  tube  r.  If  the  level  of 
the  liquid  in  D  and  C  are  then  unequal,  the  equality  may  be  restored  by 
opening  the  cock  q  for  a  few  seconds,  and  which  for  the  rest  of  the  opera- 
tion remains  closed.  The  vessel  A  is  now  held,  as  shown  in  the  cut,  so  that 
the  acid  may  come  in  contact  with  the  char,  and  the  bottle  gently  shaken  to 
cause  the  acid  to  thoroughly  mix  with  the  assay.  The  pressure  of  the  gas 
evolved  distends  the  rubber  bag  in  B  and  depresses  the  column  of  water  in 
(7.  The  stopcock  p  is  now  opened  to  allow  the  water  in  D  to  flow  out  suffi- 
ciently rapidly  to  keep  the  level  in  C  and  D  as  near  the  same  as  possible 
during  the  progress  of  the  determination.  When  all  the  gas  has  been  given 
off  and  the  level  of  the  liquid  in  C  becomes  stationary,  p  is  closed,  after 
bringing  the  water  in  D  to  the  same  level  as  that  in  (7,  and  the  volume  and. 
temperature  read  off.  A  set  of  tables  accompanying  the  instrument  gives 
the  percentage  of  carbonate  of  lime  from  the  volume  and  temperature  read- 
ings. Assuming  seven  per  cent,  to  be  the  normal  amount  of  carbonate  of 
lime  in  the  char,  any  excess,  as  shown  in  this  determination,  can  have  its 
equivalent  in  hydrochloric  acid  of  known  strength  calculated,  and  thus  the 
acid  treatment  in  the  revivifying  process  can  be  made  accurate. 

In  determining  specific  gravity,  both  apparent  and  real  specific  gravity 
(the  latter  after  boiling  the  char  with  distilled  water  to  displace  air)  are  to 
be  taken. 

(b)  Of  Scums,  Press-cakes,  and  Sucrates. — In  the  case  of  the  scums  and 
press-cakes  obtained  in  the  manufacture  of  raw  sugars,  their  chief  value  is  in 
the  lime  salts  they  contain,  which,  notably  in  the  case  of  beet-sugars,  adapt 
them  for  use  as  fertilizing  materials.  They,  however,  contain  such  amounts  of 
sugar,  either  mechanically  held,  or,  where  the  carbonatation  process  has  been 
used,  as  sucrates,  as  make  it  necessary  to  regularly  determine  the  sucrose  in 
them.  In  the  case  of  the  thin  scums  from  cane-sugar  working,  the  determina- 
tion can  be  made  exactly  as  with  an  impure  juice  before  described.  In  the 
case  of  the  heavier  press-cakes  from  beet-sugar  working,  resulting  from  car- 
bonatation, the  procedure  is  different.  Here  the  sucrate  of  lime  is  to  be  de- 
composed if  possible  without  decomposing  the  large  amount  of  accompanying 


ANALYTICAL   TESTS    AND    METHODS. 


165 


carbonate  of  lime.  This  is  done  by  careful  addition  of  acetic  acid,  con- 
trolling the  reaction  with  phenol-phthalei'n.  For  details  of  this  process, 
first  proposed  by  Sidersky,  see  Friihling  and  Schultz,  "Anleitung  ziir 
Zucker  Untersuchungen,"  3d  ed.,  p.  171. 


56. 


Sucrates,  resulting  from  the  working  of  molasses  for  sugar  by  either  of 
the  lime  or  strontium  processes  (see  p.  147),  are  analyzed  by  a  somewhat 
similar  procedure,  using  strong  acetic  acid  to  set  the  sugar  free  from  its 
combination  with  the  lime  or  strontia  and  phenol-phthalem  as  an  indicator. 


166  THE   CANE-SUGAR   INDUSTRY. 

The  excess  of  acid  is  afterwards  neutralized,  lead  solution  added,  the  solu- 
tion brought  to  strength,  and  polarized.     (Ibid.,  p.  155.) 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1876. — Food  and  its  Adulterations,  Hassall,  London. 
1877. — Tropical  Agriculture,  P.  L.  Simmonds,  London. 

Die  Chemie  der  Kohlenhydrate,  etc.,  R.  Sachsse,  Leipzig. 
1880.— The  Sugar-Beet,  L.  S.  Ware,  Philadelphia. 
1881. — The  Analysis  and  Adulteration  of  Poods,  James  Bell,  London. 
1881-90. — Bulletins  of  the  United  States  Department  of  Agriculture  on  Sugar  Experi- 
ments, Washington. 
1882. — Report  on  Sorghum-Sugar  by  the  National  Academy  of  Sciences,  "Washington. 

Foods,  Composition  and  Analysis,  A.  W.  Blyth,  London. 

Traite  de  la  Fabrication  du  Sucre,  Horsin-Deon,  Paris. 
1884. — Guide  pour  1' Analyse  brute  Melasse,  etc.,  Commerson  et  Langier,  Paris. 

Sorghum,  its  Culture  and  Manufacture,  P.  Collier,  Cincinnati. 
1887. — Lehrbuch  der  Zuckerfabrikation,  C.  Stammer,  2te  Auf.,  Braunschweig. 

Food  Adulteration  and  Detection,  J.  P.  Battershall,  New  York. 
1888. — Handbuch  der  Kohlenhydrate, 'B.  Tollens,  Breslau. 

Die  Chemie  der  Menschlichen  Nahrungs  und  Genussmittel,  J.  Konig,  3te  Auf., 
Berlin  and  New  York. 

Sugar :  A  Hand-Book  for  Planters  and  Refiners,  Lock  and  Newlands,  London. 
1889. — Die  Zuckerriibe,  H.  Briem,  Wien. 

Manuel  pratique  du  Fabricant  de  Sucre,  P.  Boulin,  Paris. 
1890. — Sugar  Analysis,  for  Refineries,  Sugar-Houses,  etc.,  F.  G.  Wiechmann,  New  York. 

Geschichte  des  Zuckers,  E.  O.  von  Lippmann,  Leipzig. 

A  Guide  to  the  Literature  of  Sugar,  H.  L.  Roth,  London. 
1891. — Anleitung  zur  Untersuchungen  der  Zuckerindustrie,  Friihling  und  Schultz,  4te 

Auf.,  Braunschweig. 

1892. — Leitfaden  fur  Zuckerfabriken-Chemiker,  E.  Preuss,  Berlin. 
1893.— Handbuch  der  Zuckerfabrikation,  F.  Stohmann,  3te  Auf.,  Berlin. 

Manual  for  Sugar-Growers,  Fr.  Watts,  London. 
1894.— Die  Zuckerfabrikation,  Dr.  B.  von  Posanner,  Wien. 

La  Sucre  et  PIndustrie  sucriere,  Horsin-Deon,  Paris. 

Manual  of  Sugar  Analysis,  J.  H.  Tucker,  4th  ed.,  New  York. 

1895. — Die  Zuckerarten  und  ihre  Derivate,  E.  von  Lippmann,  2te  Auf.,  Braunschweig. 
1897. — Hand-Book  for  Sugar  Manufacturers,  etc.,  G.  L.  Spencer,  3d  ed.,  New  York. 

Hand-Book  for  Chemists  of  Beet-Sugar  Houses,  G.  L.  Spencer,  New  York. 

Beet-Sugar  Analysis,  E.  S.  Peffer,  Chino,  California. 
1898.— Sugar-Beet  Seed  for  Farmers,  etc.,  L.  S.  Ware,  New  York. 

Das  Optische  Drehungsvermogen  Organischer  Substanzen,  H.  Landolt,  2te  Auf., 
Braunschweig. 

STATISTICS. 

1.  PRODUCTION  OF  SUGAR  FROM  THE  CANE. — The  total  production 
of  raw  sugar  from  the  sugar-cane  for  the  last  two  years  is  thus  estimated 
by  Willet  and  Gray  : 

1898-99.  1899-1900  (estimated). 

Tons.  Tons. 

Cuba      345,261  440,000 

Porto  Kico 53,825  50,000 

Louisiana      224,000  132,000 

Trinidad  (export) 53,436  45,000 

Barbadoes  (export) 42,000  35,000 

Guadeloupe 40,000  30,000 

Hayti  and  St.  Domingo 50,000  55,000 

Other  West  Indies      103,000  104,000 

Mexico  and  Central  America 22,000  24,000 

Demerara  and  Surinam 81,000  81,000 

Peru  (export)      110,000      .  100,000 

Argentine  Kepublic 80,000  90,000 

Brazil 151,495  160,000 

British  India  (export) 10,000  10,000 


BIBLIOGRAPHY   AND   STATISTICS. 


167 


1898-99.  1899-1900  (estimated). 

Tons.  Tons. 

Siam 7,000  7,000 

Java  (export) 689,281  650,000 

Philippines 76,000  70,000 

Australia  and  Polynesia 228,734  215,000 

Hawaii 252,506  275,000 

Egypt 90,000  80,000 

Mauritius,  etc 186,487  160,000 

Keunion,  etc 37,781  -35,000 

Spain 8,000  8,000 

2,941,806  2,856,000 

2.  PRODUCTION  FROM  THE  SUGAR-BEET. — The  world's  production  of 
beet-sugar  for  the  last  four  years  has  been  as  follows : 


1895-96. 

1896-97. 

1897-98. 

1898-99. 

Germany         .    .    . 

Metric  tons. 
1,617,812 

Metric  tons. 
1,836,536 

Metric  tons. 
1,847,018 

Metric  tons. 
1,700000 

Austria-Hungary  .    .    . 

781,000 

934,000 

831,600 

896,000 

France     

653,097 

735,367 

808,006 

725,000 

Russia  

775,000 

730,000 

735,000 

745,000 

Belgium                             .    .    . 

225  000 

290  000 

225  000 

210  000 

Holland 

105  000 

175  000 

125  000 

155  000 

Other  countries 

150  000 

200  000 

283  000 

250  000 

Total 

4,306,909 

4,900,903 

4,854,624 

4,681,000 

3.  IMPORTATIONS  OF  SUGAR  INTO  THE  UNITED  STATES. — The  total 
importations  of  sugar  (raw  and  refined)  during  the  last  few  years  have  been  : 

1897  .  4, 101, 211, 595  pounds,  valued  at  $81, 729, 142 

1898 3,427,260,146       "  "  77,934,097 

1899 4,399,748,654       "  "  108,124,877 


Of  this,  the  amount  of  raw  sugar  was  as  follows : 

Beet-sugar. 
1897 1,373,230,362  Ibs. 

Valued  at  .  .  $24,181,704 
1898 418, 981, 330  Ibs. 

Valued  at  .  .  $8,422,020 
1899 592,363,918  Ibs. 

Valued  at   .    .     $12,839,458 


Cane-sugar. 
1897 2,541,386,927  Ibs. 

Valued  at  .  .  $53,084,357 
1898 2, 930, 567, 531  Ibs. 

Valued  at  .  .  $67,584,076 
1899 3, 775, 340, 352  Ibs. 

Valued  at   .    .     $94,298,311 


4.    PRODUCTION  AND   CONSUMPTION  OF   SUGAR  IN   THE    UNITED 
STATES  DURING  RECENT  YEARS. 


1896. 

1897. 

1898. 

1899. 

Eefined  from  imported  sugar  . 
Manufactured  from  imported 
molasses  .            

Tons. 
1,670,963 

603 

Tons. 
1,715,607 

150 

Tons. 
1,708,937 

1  700 

Tons. 
1,844,642 

5  200 

Cane-sugar  produced  .... 
Beet-sugar          "          .... 
Maple-sugar       "          .... 
Sorghum,  etc.    "          .... 
Total  sugar        "          .... 
Consumption  per  capita  .    .    . 

243,220 
40,000 
5,000 
300 
1,960,086 
61.6  Ibs. 

310,537 
39,684 
5,000 

2,070,978 
63.7  Ibs. 

252,812 
34,453 
5,000 

2,002,902 
60.3  Ibs. 

160,400 
79,368 
5,000 

2,094,610 
61.7  Ibs. 

168     INDUSTRIES  OF  STARCH  AND  ITS  ALTERATION  PRODUCTS. 


CHAPTER  V. 

THE   INDUSTRIES   OF   STARCH   AND   ITS   ALTERATION   PRODUCTS. 

I.  Raw  Materials. 

STARCH  is  one  of  the  most  important,  as  well  as  most  widely  occurring, 
productions  of  the  vegetable  kingdom.  It  constitutes,  either  when  extracted 
from  vegetable  raw  materials,  or  more  generally  in  admixture  with  the 
other  plant  constituents,  the  staple  article  of  food  for  the  great  bulk  of  the 
human  race.  It  is  only  necessary  to  call  attention  to  the  fact  that  the  prin- 
cipal cereal  grains  used  throughout  the  world  for  food  contain  starch  as 
their  chief  ingredient,  and  that  the  tubers  of  many  plants  and  the  stems  and 
roots  of  some  trees  also  yield  starch  in  great  abundance. 

The  most  complete  enumeration  and  classification  of  starches  is  that  of 
Muter  as  amplified  by  Allen*  and  Blyth,f  by  which  they  are  divided  into 
five  groups  on  the  basis  of  their  physical  and  microscopical  differences,  as 
follows : 

I.  The  potato  group  includes  such  oval  or  ovate  starches  as  give  a  play 
of  colors  when  examined  by  polarized  light  and  a  selenite  plate  and  having 
the  hilum  and  concentric  rings  clearly  visible.     It  includes  tout  les  mois,  or 
canna  arrow-root,  potato  starch,  maranta,  or  St.  Vincent  arrow-root,  Natal 
arrow-root,  and  curcuma  arrow-root. 

II.  The  leguminous  starches  comprise  such  round  or  oval  starches  as  give 
little  or  no  color  with  polarized  light,  have  concentric  rings  all  but  invisible, 
though  becoming  apparent  in  many  cases  on  treating  the  starch  with  chromic 
acid,  while  the  hilum  is  well  marked  and  cracked,  or  stellate.      It  includes 
the  starches  of  the  bean,  pea,  and  lentil. 

III.  The  wheat  group  comprises  those  round  or  oval  starches  having 
both  hilum  and  concentric  rings  invisible  in  the  majority  of  granules.     It 
includes  the  starches  of  wheat,  barley,  rye,  chestnut,  and  acorn,  and  a  variety 
of  starches  from  medicinal  plants,  such  as  jalap,  rhubarb,  senega,  etc. 

IV.  The  sago  group  comprises  those  starches  of  which  all  the  granules 
are  truncated  at  one  end.     It  includes  sago,  tapioca,  and  arum,  together  with 
the  starch  from  belladonna,  colchicum,  scammony,  podophyllum,  canella, 
aconite,  cassia,  and  cinnamon. 

V.  The  rice  group.     In  this  group  all  the  starches  are  angular  or  polyg- 
onal in  form.     It  includes  oats,  rice,  buckwheat,  maize,  dari,  pepper,  as  well 
as  ipecacuanha. 

In  addition  to  the  differences  in  form  and  marking  mentioned  above,  the 
starch-granules  differ  in  size  according  to  their  different  sources,  so  that 
under  the  microscope  they  can  be  distinguished  by  the  measurement  of  the 
average  diameter  of  the  granule.  This  ranges,  according  to  Karmarsch, 
from  .01  to  .185  millimetre,  or  from  .0004  to  .0079  inch. 

*  Com.  Org.  Anal.,  2d  ed.,  vol.  i.  p.  335.     f  Blyth,  Foods,  Compos,  and  Anal.,  p.  139. 


RAW   MATERIALS. 


169 


For  practical  purposes  we  may  now  speak  of  two  classes  only  of  these 
starch-containing  materials, — viz.,  the  cereals  and  the  plants  in  which  the 
starch  is  extracted  from  tubers,  roots,  or  stems,  such  as  potatoes  on  the  one 
hand,  and  the  West  Indian  starch  preparations,  like  arrow-root,  sago,  and 
tapioca,  on  the  other.  As  before  stated,  starch  is  the  chief  ingredient  in  the 
cereals,  but  not  at  all  the  only  one.  The  composition  of  the  more  impor- 
tant cereals  is  thus  given  by  Bell  :* 


CONSTITUENTS. 

Wheat. 
Winter 
sown. 

Wheat. 
Spring 
sown. 

% 

Long- 
eared 
barley. 

English 
oats. 

Maize. 

.Rye. 

Carolina 
rice 
(without 
husk). 

Fat    . 

1.48 

1.56 

1.03 

5.14 

3.58 

1.43 

019 

Starch                

6371 

6586 

6351 

4978 

6466 

6187 

7766 

Sugar  (as  sucrose) 

257 

224 

1  34 

2  36 

194 

4  30 

038 

Albumen  (insoluble  in  alcohol)  
Nitrogenous  matter  (soluble  in  alcohol)  . 
Cellulose     

10.70 
4.83 
303 

7.19 
4.40 
2.93 

8.18 
3.28 
7.28 

10.62 
4.05 
13.53 

9.67 
4.60 
1.86 

9.78 
5.09 
3.23 

7.94 
1.40 
Traces 

Mineral  matter    

160 

174 

232 

266 

1.35 

185 

028 

Moisture  

12.08 

14.08 

13.06 

11.86 

12.34 

12.45 

12.15 

Total 

10000 

10000 

10000 

10000 

10000 

10000 

10000 

The  chemical  formula  of  starch  is  (C6H10O5)n.  According  to  Tollens, 
confirmed  by  Mylius,  it  is  C^H^O^ ;  according  to  Brown  soluble  starch 
is  C120H200O100,  while  for  the  ordinary  variety  he  proposes  Cwfflaof)lso.  Nageli 
stated  that  by  subjecting  the  starch-granules  to  the  slow  action  of  saliva, 
salt  solutions,  and  dilute  acids  two  substances  could  be  shown  to  be  present, 
granulose,  which  dissolved,  and  cellulose  (or,  as  it  has  been  called,  farinose), 
which  remained.  Arthur  Meyer  considers  that  there  is  only  a  single  sub- 
stance originally  present,  and  that  the  cellulose,  or  farinose,  which  remains 
is  a  decomposition  product  of  the  starch. 

Air-dried  starch  always  retains  from  eighteen  to  twenty  per  cent,  of 
water.  It  is  insoluble  in  cold  water,  alcohol,  ether,  ethereal  and  tatty  oils. 
When  it  is  heated  with  twelve  to  fifteen  times  its  bulk  of  water  to  55°  C.,  it 
begins  to  show  signs  of  change,  swelling  up,  and  at  a  temperature  of  from 
70°  to  80°  C.  (or  even  below  70°  C.  with  some  pure  starches)  the  granules 
burst  and  it  becomes  a  uniform  translucent  mass,  known  as  "  starch-paste," 
which  is  not,  however,  a  solution,  as  the  water  can  be  frozen  out  of  it. 
Boiled  with  water  for  a  long  time  it  goes  into  solution,  one  part  dissolving 
in  fifty  parts  of  water.  The  action  of  heat  upon  starch  is  to  change  it 
gradually  into  dextrine,  which  is  soluble  in  cold  water. 

One  of  the  best  known  of  the  reactions  of  starch  is  the  formation  of  a 
blue  color  with  iodine.  This  is  supposed  by  some  to  be  merely  a  physical 
combination,  but  more  generally  believed  now  to  be  a  chemical  compound. 
Mylius  finds  that  it  contains  about  eighteen  per  cent,  of  iodine,  partly  as 
hydrogen  iodide,  and  gives  it  the  formula  (€^H4aO^I)4HI.  Seyfert,  accept- 
ing the  same  formula  for  starch,  considers  that  the  iodine  compound  pos- 
sesses the  formula  (0341140020)617,  which  requires  18.61  per  cent,  of  iodine. 
It  is  not  very  stable,  being  decomposed  by  water  on  heating.  Neverthe- 
less, the  blue  coloration  is  constantly  availed  of  to  note  the  presence  or 
gradual  disappearance  or  alteration  of  starch  in  many  technical  processes. 


*  Bell,  The  Analysis  and  Adulteration  of  Foods,  Part  ii.  p.  86. 


170     INDUSTRIES  OF  STARCH  AND  ITS  ALTERATION  PRODUCTS. 

The  action  of  dilute  acids  upon  starch  brings  about  the  change  known 
as  "hydrolysis,"  and  there  is  produced  dextrine,  C12H20O10,  and  dextrose, 
CeH^Og,  the  latter  eventually  as  sole  product.  Many  ferments,  like  saliva, 
the  pancreatic  ferment,  and  especially  the  diastase  of  malt,  produge  in 
starch  a  somewhat  similar  change,  and  yield  maltose,  C^H^On,  and  a  number 
of  intermediate  products  between  this  and  starch.  A  great  deal  of  investi- 
gation has  been  devoted  to  these  intermediate  products,  and  as  yet  no  abso- 
lute agreement  has  been  reached  on  the  subject.  The  following  is  the  series 
of  products  obtained  in  this  hydrolysis  of  starch  as  stated  by  Tollens :  * 

Starch gives  a  blue  iodine  reaction. 

Soluble  starch  (amylodextrine)  ....  gives  a  blue  iodine  reaction. 

C  ery throdextrine gives  a  violet  and  red  iodine  reaction. 

Dextrines  -I  achroodextrine gives  no  iodine  reaction. 

(maltodextrine gives  no  iodine  reaction. 

Maltose reduces  Fehling's  solution,  but  not  Barfoed's  reagent. 

Dextrose reduces  Fehling's  solution,  and  also  Barfoed's  reagent. 

Other  chemists  notably  increase  the  list  of  these  intermediate  products. 
The  existence  of  erythrodextrine  as  a  distinct  compound  is  doubted  by 
some  investigators,  who  consider  it  to  be  merely  a  mixture  of  achroo-  or 
maltodextrine  with  a  little  soluble  starch,  such  a  mixture  giving  a  violet 
reaction  with  iodine.  By  over-treatment  with  acids  un fermentable  carbo- 
hydrates, of  a  character  differing  from  any  of  the  products  named,  appear 
to  form.  The  name  gallisin  has  been  given  to  a  compound  of  this  kind, 
and  the  formula  C^H^O^  ascribed  to  it.  For  a  description  of  the  con- 
ditions of  its  formation  see  later  (p.  178). 

Strong  nitric  acid  in  the  cold  acts  upon  starch,  producing  nitro  deriva- 
tives, such  as  mono-,  di-,  and  tetra-nitro-amylose,  collectively  known  as 
xyloi'din.  Alkalies  and  alkaline  earths  form  combinations  with  starch, 
the  barium  and  calcium  compounds  being  insoluble,  of  which  advantage  is 
taken  in  the  Asboth  method  for  determination  of  starch.  (See  p.  180.) 


n.  Processes  of  Manufacture. 

1.  EXTRACTION  AND  PURIFYING  OF  THE  STARCH. — Of  the  various 
starch-containing  materials  before  enumerated,  only  a  limited  number  are 
actually  utilized  for  the  extraction  of  the  starch  in  a  pure  condition, — viz., 
maize,  wheat,  rice,  potatoes,  and  arrow-root.  In  the  United  States  by  far 
the  greater  amount  is  obtained  from  maize,  or  Indian  corn,  a  limited  amount 
only  being  extracted  from  wheat.  In  Europe,  on  the  Continent,  potatoes 
serve  as  the  chief  starch-producing  material,  some  also  being  extracted  from 
wheat  and  some  from  rice,  while  in  the  West  Indies  arrow-root  starch  is 
manufactured  at  St.  Vincent  and  elsewhere. 

In  the  manufacture  of  com  starch,  after  winnowing  or  cleansing  the 
corn  by  powerful  fans,  it  is  placed  in  large  wooden  steeping- vats,  holding 
from  one  thousand  to  six  thousand  bushels.  It  remains  here  covered  with 
water  at  a  temperature  not  exceeding  140°  F.  for  from  three  to  ten  days, 
the  water  being,  however,  renewed  every  six  hours,  and  care  being  taken 
to  prevent  any  development  of  fermentation.  In  the  Durgen  system,  as 
practised  at  the  Glen  Cove  Starch  Works,  a  continuous  stream  of  water, 

*  Tollens,  Kohlenhydrate,  Breslau,  1888,  p.  177. 


PEOCESSES   OF   MANUFACTURE.  171 

heated  to  140°  F.,  flows  for  three  days  at  the  rate  of  ten  thousand  gallons  per 
day  through  each  tank,  after  which  the  corn  is  sufficiently  softened.  The 
softened  corn  is  now  ground  between  burr-stones,  a  stream  of  water  running 
continuously  into  the  hopper  of  the  mill.  As  it  is  ground,  the  thin  paste 
is  carried  by  the  stream  of  water  upon  the  shakers,  or  sieves.  These  are 
either  revolving  sieves  or  horizontal  square  shaking  sieves.  The  starch-con- 
taining magma  is  generally  reground,  and  then  the  paste  is  passed  over  the 
starch-separators.  These  are  inclined  sieves  of  silk  bolting-cloth,  which  are 
kept  in  constant  motion  and  are  sprayed  with  jets  of  water.  The  starch 
passes  through  the  bolting-cloth  with  water  as  a  milky  fluid,  while  the 
coarser  cellular  tissue,  or  husk,  of  the  corn  is  left  behind.  This  residue  is 
pressed  to  remove  water,  and  sold  as  cattle  food.  The  water  from  the 
shakers  holding  the  starch  in  suspension  is  run  into  wooden  vats,  where  the 
starch  settles,  and  the  water  is  drawn  off  and  discarded.  The  starch  is  next 
thoroughly  agitated  with  fresh  water,  to  which  a  caustic  soda  solution  of 
7°  to  8°  Baume  has  been  added,  until  the  milky  liquid  has  changed  to  a 
greenish-yellow  color.  The  object  in  adding  the  alkali  is  to  dissolve  and 
remove  the  gluten  and  other  albuminoids,  oil,  etc.  After  sufficient  agita- 
tion and  treatment  with  alkali,  the  separated  starch  and  glutinous  matter  is 
allowed  to  deposit,  the  supernatant  solution  of  gluten,  oil,  etc.,  is  allowed 
to  run  to  waste,  and  the  impure  starch  washed  and  agitated  with  water.  It 
is  allowed  to  stand  at  rest  for  fifteen  to  twenty  minutes  to  permit  insoluble 
gluten  to  subside,  when  the  top  one  of  a  series  of  plugs  arranged  in  the 
side  of  the  vat  is  withdrawn,  and  the  starch  suspended  in  water  allowed  to 
flow  by  means  of  a  gutter  into  subsiding- vats  placed  below ;  then  the  next 
lower  plug  is  drawn,  and  so  on  until  the  last  plug  has  been  drawn.  The 
plugs  are  replaced  and  the  vats  again  filled  with  water,  and  the  operation 
repeated  as  before.  This  operation,  called  the  siphoning  process,  is  gener- 
ally repeated  three  times,  and  the  three  runnings  of  starch  are  collected  in 
three  separate  vats,  forming  the  three  grades  of  starch  of  the  factory.  These 
three  grades  of  factory  starch  are  again  agitated  with  water,  sieved  through 
bolting-cloth,  and  run  finally  as  purified  starch  into  wooden  "settlers." 
After  it  has  been  compacted  sufficiently,  which  is  effected  in  boxes  with 
perforated  bottoms,  it  is  cut  into  blocks  and  dried  upon  an  absorbent  sup- 
port of  plaster  of  Paris  while  heated  in  a  current  of  warm  air.  In  drying 
out  thoroughly,  any  remaining  impurities  come  to  the  surface  with  the 
escaping  moisture  and  form  a  yellowish  crust.  When  this  is  removed,  the 
interior  is  found  to  be  perfectly  white.  The  results  on  a  bushel  of  fifty- 
six  pounds  of  corn  are  thus  stated  by  Archbold :  * 

Starch  recovered 28.000  pounds. 

Dry  refuse  for  cattle  food 13.700      " 

Bran  (in  cleansing  process) 0.728     •" 

Moisture  of  the  corn 5.626      " 

Loss  (albuminoids,  oil,  etc.) 7.946      " 

56.000      " 

In  the  Jebb  process  for  the  manufacture  of  starch  from  Indian  corn, 
recently  introduced,  the  use  of  alkali  is  entirely  avoided,  and  the  treatment 
shortened  and  simplified  by  effecting  a  mechanical  separation  of  both  the 
husk  and  the  germ  of  the  corn  before  the  starchy  part  of  the  corn  is  ground. 

*  Journ.  Soc.  Chem.  Ind.,  1887,  p.  82. 


172     INDUSTRIES  OF  STARCH  AND  ITS  ALTERATION  PRODUCTS. 

The  ground  husk  and  germ  containing  the  gluten,  albuminoids,  and  oil 
are  sold  for  cattle  food,  while  the  starch  in  a  high  state  of  purity  is  sepa- 
rately ground  and  prepared. 

In  manufacturing  starch  from  wheat  two  quite  diiferent  processes  are 
followed,  according  as  the  gluten  is  to  be  obtained  as  a  side  -product  or  not. 
In  the  process  generally  known  as  the  "  sour/7  or  fermentation,  process,  the 
gluten  is  wasted.  In  this  process  the  wheat  is  steeped  in  tanks  until  thor- 
oughly softened,  then  crushed  in  roller-mills,  and  placed  for  fermentation 
in  large  oaken  cisterns.  The  temperature  is  here  maintained  at  about  20°  C., 
and  the  operation  lasts  some  fourteen  days,  the  mass  being  well  stirred  dur- 
ing its  continuance.  The  sugar  of  the  wheat  and  a  part  of  the  starch  are 
converted  into  glucose,  which  undergoes  alcoholic  fermentation,  and  passes 
by  oxidation  into  the  acetous  fermentation  also,  acetic,  propionic,  and  lactic 
acids  being  formed.  These  rapidly  attack  and  dissolve  the  gluten,  liberating 
the  starch-granules.  The  impure  liquor  is  drawn  off  from  the  starch  mass, 
and  the  latter  is  washed,  either  in  hempen  sacks  while  being  trodden  under 
foot  or  in  drums  with  perforated  sides.  After  repeated  washings  and  set- 
tlings and  renewed  sieving  through  fine  hair  sieves  the  starch  is  sufficiently 
purified.  Wheat  starch  is  also  obtained  from  wheat  flour  without  fermenta- 
tion by  what  is  known  as  Martin's  process,  in  which  a  stiff  dough  is  made 
of  the  flour.  This  is  then  washed  in  a  fine  sieve  under  a  jet  of  water  till 
all  the  starch  has  escaped  as  a  milky  fluid.  This  leaves  the  gluten,  of  which 
about  twenty-five  per  cent,  of  the  weight  of  the  flour  is  gotten  suitable  for 
use  in  the  manufacture  of  macaroni,  or  to  be  used  instead  of  albumen  or 
casein  in  calico-printing. 

In  the  manufacture  of  potato  starch,  the  potatoes  are  washed  and  then 
pulped  by  a  grating  or  rasping  machine.  The  grated  mass,  made  into  a 
paste  with  water,  then  goes  at  once  into  the  sieving  machine,  where  it  is 
rubbed  by  revolving  brushes  against  the  wire  or  hair  sides  of  the  rotating 
cylinder,  while  a  current  of  water  is  continuously  washing  out  the  fine  starch 
from  the  pulp.  The  sifted  and  washed  starch  deposits  in  large  tanks,  where 
it  is  repeatedly  washed  by  agitation  and  settling  with  fresh  waters.  It  is 
then  spread  out  on  absorbent  slabs  to  dry,  or  is  dried  in  centrifugals  or  filter- 
presses. 

2.  MANUFACTURE  OF  GLUCOSE,  OR  GRAPE-SUGAR. — As  stated  on  a 
preceding  page,  the  action  of  dilute  acids  converts  starch  into  dextrine, 
maltose,  and  dextrose,  the  last  of  which  becomes  by  continued  action  the 
sole  product.  As  it  is  also  the  most  important  product  of  this  action  of 
acids,  we  shall  take  it  up  first.  The  purified  starch  obtained  as  described  in 
the  preceding  section,  while  yet  moist,  is  taken  for  the  treatment  with  acids. 
The  "  conversion"  is  accomplished  in  either  open  or  closed  converters,  or 
partly  in  one  and  partly  in  the  other.  The  open  converters  are  wooden 
vats,  generally  of  three  thousand  to  four  thousand  gallons  capacity,  and 
serve  to  treat  the  starch  from  one  thousand  bushels  of  corn.  They  are  pro- 
vided with  copper  steam-coils,  either  closed  or  perforated.  Sulphuric  acid 
is  generally  employed  in  the  conversion,  though  other  acids  have  been  used. 
The  quantity  of  the  acid  employed  varies  with  the  object  of  the  manufac- 
turer. For  the  production  of  "  glucose,"  a  liquid  product  which  contains 
much  dextrine,  a  smaller  quantity  is  used  than  when  solid  "  grape-sugar"  is 
to  be  produced,  in  which  the  conversion  into  dextrose  is  much  more  com- 
plete. The  proportion  varies  from  one-half  pound  oil  of  vitriol  to  one  and 
a  quarter  pounds  per  hundred  pounds  of  starch.  When  the  open  converter 


PEOCESSES  OF   MANUFACTURE. 


173 


is  used,  a  few  inches  of  water  is  introduced  and  the  acid  added,  or  half  the 
acid  may  be  added  to  the  starch  mixture.  The  acid  water  is  brought  to  a 
boil,  and  the  starch,  previously  mixed  with  water  to  a  gravity  of  from  18°  to 
21°  Baume,  is  slowly  pumped  in,  keeping  the  liquid  constantly  boiling. 
When  all  the  starch  has  been  introduced,  the  whole  is  boiled  until  the  iodine 
test  ceases  to  give  a  blue  color  and  shows  a  dark  cherry  color.  The  boiling 
is  usually  continued  for  about  four  hours.  The  closed  converters  may  be 
made  from  strong  wooden  vats  or  may  be  of  copper  ;  they  are  provided  with 
safety-valves,  and  are  made  of  sufficient  strength  to  stand  a  pressure  of  six 

atmospheres.  Fig. 
57  shows  the  form 
first  introduced  in 
this  country  by  T. 
A.  Hoffmann,  while 
Fig.  58  shows  the 
form  proposed  by 
Maubre*  in  L  o  n- 
don.  In  this  case  the 
starch  is  mixed  with 
water  to  a  gravity 
of  from  11°  to  16° 
Baume".  This  with 
the  acid  -is  intro- 
duced into  the  con- 
verter, and  the  whole 
is  heated  under  a 
pressure  of  f r o m 
forty-five  to  s  e  v- 
enty-fi  ve  pounds  per 
square  inch.  The 
time  required  for 
the  conversion  i  s 
much  shorter  than 
in  the  open  con- 
verters. The  use  of 
open  and  closed  con- 
The  starch  and  water  of  a  gravity 


verters  successively  is  often  resorted  to. 


of  15°  or  16°  Baum6  is  first  boiled  in  the  open  converter  for  from  one  to 
two  hours,  then  transferred  to  the  closed  converter  and  boiled  under  a  press- 
ure of  from  forty-five  to  seventy-five  pounds  per  square  inch.  The  time  of 
this  boiling  varies  from  ten  minutes  to  half  an  hour. 

When  the  starch  has  been  sufficiently  converted,  according  to  the  product 
desired,  the  liquor  is  run  into  the  neutralizing-vats.  Here  a  sufficient  quan- 
tity of  marble-dust  is  added  to  completely  neutralize  the  sulphuric  acid.  A 
little  fine  bone-black  is  generally  added  at  the  same  time.  It  is  then  allowed 
to  cool  and  deposit  the  sulphate  of  lime.  The  liquor  having  a  gravity  of 
12°  to  18°  Baume,  and  known  as  "  light  liquor,"  is  next  filtered  through  bag 
filters  of  cotton  cloth  or  filter-presses.  In  many  establishments  the  liquor 
is  now  treated  with  sulphurous  acid  gas  to  prevent  fermentation,  and  prob- 
ably to  some  extent  to  act  as  a  bleaching  agent.  It  is  then  filtered  through 
bone-black,  by  which  it  is  decolorized  and  at  the  same  time  freed  from  vari- 
ous soluble  impurities.  Concentration  is  then  effected  in  the  vacuum-pan  at 


174     INDUSTRIES  OF  STARCH  AND  ITS  ALTERATION  PRODUCTS. 

a  temperature  of  about  140°  F.  until  it  has  a  gravity  of  from  28°  to  30° 
Baume",  when  it  is  called  "heavy  liquor."  A  second  .bag  or  filter-press 
filtration  is  now  resorted  to  in  many  factories  to  remove  the  sulphate  of  lime, 
which  separates  out  at  this  degree  of  concentration.  It  is  then  filtered  a 
second  time  through  bone-black  to  secure  complete  decolorization  and  puri- 
fication. The  final  concentration  is  effected  by  boiling  the  liquor  in  the 
vacuum-pan  until  it  reaches  40°  to  42°  Banine".  That  product  in  which 
the  conversion  has  been  least  complete  remains  liquid,  and  is  called  "  glu- 

FIG.  58. 


cose"  in  the  trade ;  that  which  is  ready  to  solidify  is  known  as  "  grape- 
sugar."  Dr.  Arno  Behr  has  patented  a  process  for  obtaining  the  solid  grape- 
sugar  in  pure  crystals.  While  it  is  still  liquid  there  is  added  to  it  a  small 
quantity  of  crystallized  anhydrous  dextrose.  The  mixture  is  filled  into 
moulds,  and  in  about  three  days  it  is  found  to  be  a  solid  mass  of  crystals 
of  anhydrous  dextrose.  The  blocks  are  then  placed  in  a  centrifugal  machine 
to  throw  out  the  still  liquid  syrup,  and  the  anhydrous  dextrose  remains  as 
a  crystalline  mass. 

3.  MANUFACTURE  OF  MALTOSE. — By  the  action  of  the  diastase  of 
malt  upon  starch  is  formed  mainly  maltose.  Dilute  sulphuric  acid  will 
convert  this  by  prolonged  boiling  into  dextrose,  but  diastase  alone  will  not 
so  convert  it.  The  manufacture  of  maltose  on  a  large  scale  as  a  prepara- 
tion for  use  in  beer-brewing  to  simplify  the  preparation  of  a  suitable  wort 
has  been  attempted  by  several.  Dubrunfaut  and  Cuisinier  patented  a  pro- 
cess in  1883  for  preparing  maltose,  either  as  syrup  or  crystallized,  by  the 
following  procedure  :  One  part  of  green  or  partially  dried  malt  is  warmed 
with  two  to  three  parts  of  water,  digested  for  several  hours  at  30°  C.,  and 
afterwards  filter-pressed  to  obtain  an  "infusion"  of  malt.  One  part  of 
starch-flour  is  then  suspended  in  two  to  twelve  parts  of  water,  and  five  to 
ten  per  cent,  of  infusion  added,  the  whole  gradually  warmed  to  80°  C.,  then 
heated  under  a  pressure  of  one  and  a  half  atmospheres  for  thirty  minutes, 
quickly  cooled  to  48°  C.,  and  treated  with  five  to  twenty  per  cent,  of  infu- 
sion and  hydrochloric  acid  (from  six  to  twenty-five  cubic  centimetres  of  acid 
per  one  hundred  litres).  After  one  hour  the  mass  is  filtered  through  filter- 
paper  fastened  upon  linen  cloth.  The  solution  is  allowed  to  stand  at  48°  C. 
for  twelve  to  fifteen  hours,  then  concentrated  to  28°  B.,  filtered,  again  concen- 
trated to  38°  B.,  filtered  through  animal  charcoal,  and  allowed  to  crystallize. 
A  sample  of  the  syrup  made  from  corn-starch  by  the  Brussels  Maltose  Com- 


PROCESSES   OF  MANUFACTURE.  175 

pany  working  under  this  patent  was  analyzed  by  Marcker,*  and  found  to 
contain  19.8  per  cent,  water,  78.7  per  cent,  maltose,  1.5  percent,  non-sugar, 
and  no  dextrine.  The  process  is,  however,  said  to  have  failed  as  yet  of 
commercial  success.  Saare,f  who  has  recently  investigated  it,  shows  that 
the  complete  conversion  into  maltose  only  takes  place  with  weak  mashes,  and 
he  concludes  from  his  results  that  the  process  is  not  suitable  for  German 
distilleries  under  the  present  conditions.  O'Sullivan  and  Valentin  J  have 
also  patented  a  process  for  producing  from  starch,  or  starch-yielding  sub- 
stances, preferably  from  rice,  a  compound  solid  body,  which  the  inventors 
term  "  dextrine-maltose,"  consisting  of  the  same  proportional  quantities  of 
dextrine  and  maltose  as  are  ordinarily  obtained  from  malt  by  a  properly-con- 
ducted mashing  process,  and  which  it  is  intended  should  replace  a  portion 
of  the  malt  used  in  brewing.  For  details,  see  original  article.  Perfectly 
pure  maltose  can  be  obtained  by  Herzfeld's  process  of  repeatedly  extracting 
with  alcohol  from  the  syrupy  product  of  the  action  of  malt  upon  starch. 
The  alcohol  precipitates  the  dextrine,  but  dissolves  the  maltose,  which  can 
then  be  obtained  in  crystalline  condition. 

4.  MANUFACTURE  OF  DEXTRINE. — This  may  be  eifected  by  acting  upon 
starch  with  heat  alone,  by  the  action  of  dilute  acids  and  heat,  or  by  the 
action  of  diastase.     The  first  and  second  of  these  methods  are  followed  in 
preparing  the  solid  product.     In  the  manufacture  by  heat  alone  the  limits 
of  temperature  are  212°  to  250°  C.,  although  Payen  says  that  200°  to  210° 
C.  produces  the  most  perfectly  soluble  dextrine.     The  starch  is  heated  in 
revolving  drums,  which  are  frequently  double-jacketed,  and  contain  oil  in 
the  outer  space  in  order  to  insure  uniform  heating.     After  the  moisture  is 
given  off,  the  loss  of  weight  in  roasting  is  small,  two  hundred  and  twenty 
pounds  of  starch  giving  one  hundred  and  seventy-six  pounds  of  finished 
dextrine. 

In  the  manufacture  by  the  aid  of  acids  the  starch  is  mixed  with  dilute 
nitric  or  hydrochloric  acid  so  as  to  form  a  damp  powder.  This  is  exposed 
to  a  temperature  of  100°  to  120°  C.  until  the  transformation  is  complete, 
which  can  be  determined  by  applying  the  iodine  test  from  time  to  time. 
The  process  must  be  arrested  promptly  when  the  starch  is  all  changed,  or 
the  dextrine  will  pass  rapidly  into  glucose.  Oxalic  acid  is  also  sometimes 
employed  in  the  manufacture  of  dextrine. 

5.  MANUFACTURE  OF  SUGAR-COLORING  (Caramel,  or  Zucker-couleur). — 
Very  considerable  quantities  of  an  artificial  coloring  material  for  use  in 
coloring  beer,  rum,  cognac,  and  high  wines  is  made  on  the  Continent  of 
Europe  from  starch.     For  the  manufacture  of  rum  and  cognac  coloring, 
starch  is  treated  with  dilute  sulphuric  acid,  as  before  described  for  the  manu- 
facture of  dextrose  and  dextrine  mixtures,  but  the  heating  is  continued  until 
all  the  dextrine  has  been  changed  into  dextrose,  as  determined  by  taking  a 
sample  from  time  to  time  and  testing  it  with  an  excess  of  ninety-six  per  cent, 
alcohol.     When  no  longer  any  turbidity  from  separated  dextrine  shows,  the 
reaction  is  considered  as  finished.     The  sulphuric  acid  is  then  neutralized 
with  carbonate  of  lime,  and  after  sufficient  standing  the  clear  liquor  is  run 
off  from  the  precipitated  sulphate  of  lime.     It  is  now  concentrated  to  36° 
B.  and  filtered.     The  hot  filtrate  is  then  run  into  a  vessel  provided  with 

*  Jahresber.  der  Chem.  Tech.,  1886,  p.  613. 
f  Dingier,  Polytech.  Journ.,  266.,  p.  418. 
j  Journ.  Soc.  Chem.  Ind.,  1888,  p.  446. 


176     INDUSTRIES  OF  STARCH  AND  ITS  ALTERATION  PRODUCTS. 

mechanical  agitation  and  heated  to  boiling,  when  crystallized  soda  salt  (three 
kilos,  of  soda  to  one  hundred  kilos,  of  sugar  solution)  is  added  in  small  por- 
tions at  a  time.  The  contents  of  the  kettle  froth  and  must  be  continuously 
stirred.  White  and  inflammable  vapors  are  given  off  and  the  color  rapidly 
deepens.  The  heat  is  now  gradually  lessened  to  prevent  carbonizing  of  the 
contents  of  the  vessel,  and  the  color  is  tested.  A  drop  chilled  by  being 
dropped  into  water  should  harden  and  be  brittle  and  should  taste  bitter. 
The  contents  of  the  kettle  are  then  cooled  at  once  by  running  in  hot  water. 
When  the  production  of  the  color  is  completed,  the  contents  of  the  kettle 
are  extracted  with  water,  filtered  to  remove  carbonized  particles,  and  then 
tested  as  to  quality.  The  coloring  is  made  in  several  grades  or  depths  of 
color,  which  are  also  differently  soluble,  the  one  in  seventy-five  per  cent, 
alcohol  and  the  other  in  eighty  per  cent,  alcohol.  For  beer-  or  wine-coloring 
it  is  not  necessary  to  be  so  careful  to  use  a  glucose  freed  perfectly  from 
dextrine,  and,  instead  of  soda,  ammonium  carbonate  is  taken.  The  product 
is  soluble  in  water,  but  not  so  readily  in  alcohol. 


m.  Products. 

1.  STARCH. — The  properties  and  action  of  reagents  upon  starch  have 
already  been  noted  in  speaking  of  it  as  a  raw  material.  It  is  only  necessary 
to  subjoin  a  few  analyses  of  commercial  starches  in  order  to  show  the  char- 
acter of  that  usually  obtainable.  Those  of  potato  and  wheat  starch  are  by 
J.  Wolff,  as  quoted  in  "  Wagner's  Chemical  Technology/7  and  those  of  corn 
starch  are  by  Dr.  Archbold,  as  given  by  him  in  the  "  Journal  of  the  Society 
of  Chemical  Industry,"  1887,  p.  188. 


PERCENTAGE  COMPOSI- 
TION. 

Potato 
starch. 
(Wolff.) 

Wheat 
starch,  I. 
(Wolff.) 

Wheat 
starch,  II. 
(Wolff.) 

Corn 
starch,  I. 
(Archbold.) 

Corn 
starch,  II. 
(Archbold.) 

Corn 
starch.  III. 
(Archbold.) 

Starch          .        .    . 

83  59 

83  91 

7963 

98.50 

92.88 

90.33 

Gluten  

0  10 

1.84 

.Cellulose  

0.50 

1  44 

3.77 

|     2.38 

|     4.25 

Ash  
Water  

0.53 
15.38 

0.03 
14.52 

0.55 
14.20 

0.30 
1.20 

0.60 
4.14 

0.65 
4.77 

Total    

100.00 

10000 

100.00 

100.00 

100.00 

100.00 

2.  GLUCOSE  AND  GRAPE-SUGAR. — Starch-sugar  appears  in  commerce  in 
a  great  variety  of  grades  and  under  a  similar  variety  of  names.  As  already 
said,  in  the  United  States  the  name  glucose  is  in  general  applied  to  the 
liquid  products,  while  that  of  grape-sugar  is  given  to  the  solid  products. 
In  France,  where  large  quantities  of  similar  products  are  manufactured,  the 
liquid  product  is  known  as  "  sirop  cristal"  and  the  solid  product  "  glucose 
mass6."  The  following  analyses  show  the  composition  of  the  commercial 
products,  the  first  five  being  American  products  as  examined  by  the  Com- 
mittee of  the  National  Academy  of  Sciences,*  and  the  last  two  being  French 
as  examined  by  L.  von  Wagner  :  f 


Keport  on  Glucose,  Washington,  1884,  p.  22. 
Dingier,  Polytech.  Journ.,  266,  p.  470. 


PRODUCTS. 


177 


PERCENTAGE  COMPO- 
SITION. 

I. 

Glucose 
solution. 

II. 
Glucose 
solution. 

III. 
Glucose 
solution. 

Solid 
grape-sugar. 

Crystallized 
grape-sugar. 

"  Sirop 
cristal." 

"  Glucose 
masse." 

36.5 

36.5 

39.0 

72.1 

99.4 

64.0 

64-66 

JVIitltOSe 

19.3 

7  6 

Dextrin  6 

29.8 

40.9 

41.4 

9.1 

21.0 

18-22 

Water             .    .    . 

14.2 

15.3 

19.3 

16.6 

0.6 

15.0 

15-18 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

3.  MALTOSE. — Maltose  forms  fine  white  crystalline  needles  aggregating 
in  warty  groups,  which  have  a  faint  sweetish  taste.     It  is  soluble  in  water 
and  methyl  and  ethyl  alcohol,  but  more  difficultly  in  the  last  than  dextrose. 
Its  formula  is  C12H22On,  and  it  crystallizes  with  one  molecule  of  water, 
which  it  loses  slowly  at  100°  C.  in  a  vacuum.     Its  specific  rotatory  power  is, 
according  to  Meissl,  (8)D  =  140.375  —  .01837  P  —  .095  T,  where  P  equals 
the  percentage  strength  of  the  solution  and  T  the  temperature.     A  ten  per 
cent,  solution  at  20°   C.  would  then  be   138.3°.     O'Sullivan  takes  it  as 
139.2°  for  a  ten  per  cent,  solution.     Its   reducing  power  with  Fehling's 
solution  is  frequently  stated  to  be  two-thirds  that  of  dextrose,  but  Brown 
and  Heron  as  well  as  O'Sullivan  make  it  more  exactly  sixty-two  per  cent, 
of  that  shown  by  dextrose.     It  has  no  action,  however,  upon  Barfoed's 
reagent  (see  p.  180),  which  is  reduced  by  dextrose.     Maltose  is  said  to  be 
directly  and  completely  fermentable  without  previous  change  into  dextrose, 
but  more  slowly  than  this  latter,  so  that  if  a  mixture  of  maltose  and  dex- 
trose be  fermented  with  yeast,  the  whole  of  the  dextrose  disappears  before 
the  former  sugar  is  acted  upon. 

4.  DEXTRINE. — Pure  dextrine  is  a  white  amorphous  solid.     It  is  taste- 
less, odorless,  and  non-volatile.     It  is  completely  soluble  in  cold  water,  but 
the  commercial  varieties  usually  leave  from  twelve  to  twenty  per  cent,  or 
even  more  of  starch  and  other  insoluble  residue  when  dissolved.     Heated 
with  dilute  acids  it  yields  maltose  and  ultimately  dextrose.     It  is  unferment- 
able  if  free  from  sugar.     It  has  no  reducing  power  on  Fehling's  solution. 
Probably  what  is  called  dextrine  is  a  mixture  of  products  obtained  in  the 
breaking  down  of  the  complex  starch -molecules.     Some  investigators  claim 
to  have  obtained  sixteen  distinct  modifications  or  varieties  of  dextrine  in 
this  way.     We  have  before  (see  p.  170)  alluded  to  amylodextrine,  erythro- 
dcxtrine,  achroodex trine,  and  maltodextrine. 

Commercial  dextrine,  or  "  British  gum,"  gives  a  brown  coloration  with 
iodine,  and  probably  consists  largely  of  erythrodextrine.  The  following 
analyses  by  fe.  Forster  give  an  idea  of  the  composition  of  the  dextrines  usu- 
ally obtainable : 


PERCENTAGE  COMPOSITION. 

First 
quality 
dextrose. 

Dark- 
burned 
starch. 

Brown 
•  dextrine. 

Gommel- 
ine. 

Old 

dextrine. 

Light- 

burned 
starch. 

Dextrine  

72  45 

70  43 

63  60 

59  71 

49  78 

5  34 

Susjtir    

8.77 

1  92 

7  67 

5  76 

1  42 

0.24 

Insoluble  

13  14 

19  97 

14  51 

20  64 

30  80 

86  47 

Water  

5  64 

7  68 

14  22 

13  89 

18  00 

7  95 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

12 


178     INDUSTRIES  OF  STAECH  AND  ITS  ALTERATION  PRODUCTS. 

Dextrine  is  used  as  a  substitute  for  natural  gums,  especially  for  gum 
arabic.  It  is  thus  used  in  calico-printing  and  in  the  mordanting  and  print- 
ing of  colors  upon  most  other  classes  of  textile  goods,  for  mucilage,  for 
f  lazing  cards  and  paper,  as  warp-dressing,  and  in  the  manufacture  of  beer, 
t  forms  the  crust  on  bread  by  the  change  of  the  starch  of  the  flour  in 
baking,  and  is  present  in  most  products  from  starch  or  starch-sugar. 

5.  UNFERMENTABLE  CARBOHYDRATES  (Gallisin). — The  presence  of 
an  unfermentable  carbohydrate  in  starch-sugar  was  long  since  pointed  out 
by  O'Sullivan.  The  compound  which  has  been  specially  studied  is  known 
as  gallisin,  and  is  prepared  by  fermenting  a  twenty  per  cent,  solution  of 
starch-sugar  with  yeast  at  18°  or  20°  C.  for  five  or  six  days.  The  resultant 
liquid  was  filtered,  evaporated  to  a  syrup  at  100°  C.,  and  shaken  with  a 
large  excess  of  absolute  alcohol.  The  treatment  with  alcohol  was  repeated 
several  times  until  the  unaltered  sugar  and  other  impurities  were  removed,  the 
syrup  being  converted  into  a  yellowish  crumbling  mess,  which,  by  pound- 
ing in  a  mortar  with  a  mixture  of  equal  parts  of  alcohol  and  ether,  was 
obtained  as  a  gray  powder.  After  purifying  with  animal  charcoal  and  dry- 
ing over  sulphuric  acid,  the  gallisin  was  obtained  as  a  white  amorphous 
extremely  hygroscopic  powder.  Its  taste  is  at  first  sweet,  but  afterwards 
becomes  insipid.  It  is  easily  decomposable  by  heat,  even  at  100°  C.  It  is 
readily  soluble  in  water,  nearly  insoluble  in  absolute  alcohol,  and  but  slightly 
more  soluble  in  methyl  alcohol,  in  which  respect  it  diifers  from  dextrose. 
Gallisin  is  stated  to  have  the  composition  C^I^Oio*  Its  concentrated  aque- 
ous solution  is  distinctly  acid  to  litmus  and  a  sparingly  soluble  barium 
compound  may  be  obtained  therefrom  by  adding  alcoholic  baryta.  It 
reduces  nitrate  of  silver  on  heating,  especially  on  addition  of  ammonia, 
reduces  bichromate  and  permanganate,  and  precipitates  hot  Fehling's  solu- 
tion. Its  cupric  oxide  reducing  power  (dextrose  =  100)  is  stated  to  be  45.6°. 
Gallisin  is  dextro-rotatory,  the  value  for •  SD  being  stated  to  be  80.1°  in 
twenty-seven  per  cent.,  82.3°  in  ten  per  cent,  and  84.9°  in  1.6  per  cent, 
solutions.  By  heating  with  dilute  sulphuric  acid  for  some  hours  gallisin 
yields  a  large  proportion  of  dextrose,  but  its  complete  conversion  has  not 
so  far  been  effected. 

It  is  doubtful  whether  "  gallisin"  as  hitherto  obtained  is  really  a  definite 
compound,  but  the  possibility  of  isolating  a  reducing  or  optically  active 
body  from  the  liquid  left  after  fermenting  solutions  of  many  specimens  of 
starch-sugar  cannot  be  ignored  in  considering  the  composition  of  commer- 
cial glucose. 

IV.   Analytical  Tests  and  Methods. 

1.  FOR  STARCH. — The  usual  method  for  the  determination  of  starch 
is  to  invert  by  the  action  of  dilute  acid,  and  then  determine  the  dextrose 
produced  by  the  aid  of  Fehling's  solution.  In  this  case  one  hundred  parts 
of  dextrose  are  taken  as  indicating  ninety  of  starch.  It  has  been  found, 
however,  that  the  change  to  dextrose  by  the  aid  of  dilute  sulphuric  acid  is 
not  complete,  that  other  non-reducing  bodies  are  formed,  and  that  but 
ninety-five  per  cent,  of  the  starch  is  converted  into  dextrose.  The  hydrol- 
ysis is  more  completely  effected  by  the  aid  of  hydrochloric  acid,  as  carried 
mit  in  Sachsse's  method.  2.5  to  3  grammes  of  dry  starch  (or  so  much 
of  the  starch-containing  substance  as  would  correspond  to  this  amount 
of  starch)  are  placed  in  a  flask  with  two  hundred  cubic  centimetres  of  water 
and  twenty  cubic  centimetres  of  hydrochloric  acid  and  heated  on  the  water- 


ANALYTICAL  TESTS  AND  METHODS. 


179 


FIG.  59. 


bath  with  inverted  condenser  for  three  hours.  (Marcker  states  that  heating 
for  three  hours  with  this  amount  of  hydrochloric  acid  does  not  give  more 
than  ninety-six  to  ninety-seven  per  cent,  of  the  starch  as  sugar,  as  some  of 
the  latter  is  destroyed.  He  recommends  using  fifteen  cubic  centimetres  of  acid 
and  heating  for  two  hours.)  The  contents  of  the  flask  are  then  neutralized 
with  potassium  hydrate  or  sodium  carbonate,  filled  to  the  mark,  and  the 
dextrose  determined  by  Fehling's  solution.  If  other  carbohydrates  or 
cellulose  are  present,  which  would  be  also  converted  into  dextrose  by 

hydrochloric  acid,  the  starch  must  be 
previously  brought  into  the  soluble 
form,  which  may  be  done  by  heating 
with  water  to  130°  C.  in  a  pressure- 
flask  like  that  of  Lintner,  shown  in 
Fig.  59.  Or  the  starch  may  be  hydro- 
lyzed  in  part  by  infusion  of  malt 
or  diastase  at  62.5°  C.,  filtered  from 
cellulose,  etc.,  and  then  treated  with 
hydrochloric  acid  for  complete  hydrol- 
ysis as  above.  In  this  latter  case,  the 
process  of  Reinke  *  is  the  simplest. 
Three  grammes  of  the  sample  as  finely 
powdered  as  possible  are  heated  to  boil- 
ing with  fifty  cubic  centimetres  of  water, 
cooled  to  62.5°  C.,  and  hydrolyzed  for 
an  hour  at  this  temperature  with  .05 
gramme  of  diastase.  This  is  prepared 
according  to  Lintner's  procedure,  by 
making  an  alcoholic  twenty  per  cent, 
extract  (1 : 3)  of  raw  malt,  adding 
to  the  filtrate  two  volumes  of  ninety- 
six  per  cent,  alcohol,  separation  of  the 
precipitated  diastase,  washing  with  alcohol  and  ether,  and  drying  in  a  des- 
iccator. The  mixture  is  then  cooled,  diluted  with  water  to  two  hundred 
and  fifty  cubic  centimetres,  and  filtered.  Of  the  filtrate,  two  hundred  cubic 
centimetres  are  taken  and  hydrolyzed,  as  before  described,  with  fifteen  cubic 
centimetres  of  hydrochloric  acid  of  1.125  specific  gravity  for  two  and  a  half 
hours,  when  the  solution  is  neutralized  and  the  dextrose  determined. 

A  more  elaborate  course  of  treatment,  following  in  the  main  the  same 
lines  as  the  procedure  of  Reinke  just  described,  but  stopping  with  the 
action  of  the  diastase,  has  been  published  by  O'Sullivan,  and  is  given  at 
length  by  Allen,  f  In  this  case  the  filtered  liquid,  assumed  to  contain  noth- 
ing but  maltose  and  dextrine,  is  made  up  to  one  hundred  cubic  centimetres, 
and  the  density  determined.  It  is  then  tested  with  Fehling's  solution  for 
the  maltose,  and  the  dextrine  deduced  from  the  rotatory  power  of  the  solution. 
The  maltose  found,  divided  by  1.055,  gives  the  corresponding  weight  of  starch, 
which,  added  to  the  dextrine  found,  gives  the  total  number  of  grammes  of 
starch  represented  by  one  hundred  cubic  centimetres  of  the  solution. 

The  method  for  the  determination  of  starch  in  cereals  most  generally 
used  in  Germany  at  present  is  that  of  Marcker.J  Three  grammes  of  sub- 

*  Jahresber.  Chem.  Technol.,  1887,  p.  863. 

f  Commercial  Organic  Analysis,  3d  ed.,  vol.  i.  p.  415. 

±  Jahresber.  Chem.  Technol.",  1885,  p.  863. 


180     INDUSTRIES  OF  STARCH  AND  ITS  ALTERATION  PRODUCTS. 

stance  are  placed  in  a  small  beaker  (preferably  of  metal),  which  is  placed  as 
one  of  several  in  a  Soxhlet  pressure-boiler,  or  the  test  is  carried  out  in  the 
Lintner  pressure-flask,  figured  on  the  preceding  page,  and  heated  to  the  tem- 
perature of  boiling  water.  It  is  then  cooled  to  60°  to  65°  C.,  five  cubic  centi- 
metres of  thin  malt  infusion  are  added,  and  it  is  digested  at  this  temperature 
for  some  twenty  minutes.  It  is  then  made  faintly  acid  (one  cubic  centi- 
metre of  tartaric  acid  suffices)  and  heated  under  a  pressure  of  three  to  four 
atmospheres.  It  is  then  cooled  down  and  an  additional  five  cubic  centi- 
metres of  malt  infusion  added,  with  which  it  is  digested  an  half-hour. 
The  solution  is  then  brought  up  to  one  hundred  cubic  centimetres,  filtered, 
and  determined  with  Fehling's  solution,  either  by  titration  or  by  weighing 
the  reduced  copper. 

Of  other  methods  proposed  for  starch  determinations  it  is  only  neces- 
sary to  notice  the  Asboth  method,  proposed  in  1887.  It  depends  on  the 
fact  that  starch  forms  a  compound  with  baryta-water,  C24H40O20BaO,  con- 
taining 19.1  per  cent,  of  BaO,  which  is  insoluble  in  forty-five  per  cent, 
alcohol.  The  baryta- water  is  used  in  excess,  and  the  free  alkaline  earth 
determined  by  titration  with  decinormal  hydrochloric  acid.  Numerous 
experimenters  have  taken  exception  to  the  method  that  the  results  were 
variable,  and  that  starch  combined  with  varying  amounts  of  barium  oxide. 
To  these  objections  the  author  has  recently  replied,*  and  claims  that  the 
presence  of  fat  in  the  cereals  interferes  with  the  accuracy  of  the  determina- 
tion, and  that  if  the  fat  be  previously  extracted  by  ether,  the  determinations 
in  the  fat-free  residue  are  accurate  and  concordant.  J.  Napier  Spence,  in 
the  "  Journal  of  the  Society  of  Chemical  Industry"  for  1888,  p.  77,  has  also 
come  to  the  defence  of  the  Asboth  method  and  shown  the  conditions  under 
which  it  yields  accurate  results. 

2.  GLUCOSE,  OR  DEXTROSE. — For  the  determination  of  dextrose  alone  the 
Fehling's  solution  affords  the  most  accurate  means.     For  its  use,  see  analysis 
of  raw  sugars,  p.  158.     In  the  absence  of  any  other  optically  active  body 
its  examination  with  the  polariscope  will  also  suffice.    For  mixtures  like  com- 
mercial glucose,  which  contains  dextrose,  maltrose,  and  dextrine,  see  later. 

3.  MALTOSE. — This  variety  of    sugar,  as   before   stated,  has   optical 
activity  and  reducing  power  on  Fehling's  solution.     It  can,  however,  be 
distinguished   from  dextrose  by  its  failure  to  reduce  Barfoed's  solution, 
which  is  reduced  by  dextrose  and  invert  sugar.     This  reagent  is  made  by 
dissolving  one  part  of  neutral  copper  acetate  in  fifteen  parts  of  water,  to 
two  hundred  cubic  centimetres  of  which  five  cubic  centimetres  of  thirty- 
eight  per  cent,  acetic  acid  is  added.      Boiled  for  several  minutes  with 
maltose  solution  it  shows  no  reduction. 

4.  DEXTRINE. — Pure  dextrine  differs  from  dextrose  and  maltose  in 
showing  no  reducing  power  with  either  Fehling's  solution  or  with  Knapp's 
mercuric  cyanide  solution.     It  can,  indeed,  be  freed  from  admixture  with 
dextrose  and  maltose  by  heating  with  an  excess  of  an  alkaline  solution  of 
mercuric  cyanide,  which  oxidizes  these  two  varieties  of  sugar,  leaving  the 
dextrine  unaffected.     (See  Wiley's  method  on  next  page.) 

5.  COMMERCIAL  GLUCOSE  AND  SIMILAR  MIXTURES  DERIVED  FROM 
STARCH. — As  commercial  glucose  is  likely  to  be  a  mixture  of  the  three 
compounds,  dextrose,  maltose,  and  dextrine,  its  analysis  and  the  determina- 
tion of  the  several  constituents  becomes  a  frequently-recurring  problem. 

*  Chemiker  Zeitung,  1889,  pp.  591  and  611. 


ANALYTICAL   TESTS   AND   METHODS.  181 

Three  methods  have  been  proposed.  The  first,  by  Allen,*  requires  the 
determination  of  moisture  and  ash  in  the  sample,  which,  subtracted  from 
100,  leaves  the  total  organic  solids,  0.  The  apparent  specific  rotatory 
power,  S9  and  the  cupric  oxide  reducing  power  (in  terms  of  dextrose  re- 
duction =  100),  K9  are  now  determined.  Then,  if  m  be  the  maltose,  g  the 
dextro-glucose,  and  d  the  dextrine,  Allen  determines  the  respective  per- 
centages by  the  use  of  the  formulas  m  — f  8 — 'J-r- 

.313,  g  =  K — .62m,  and  d=0  —  (g  +  m).  The  author  states  that  the 
presence  of  gallisin  or  other  unfermentable  sugar  may  vitiate  the  values  of 
K  and  8,  as  observed,  and  so  make  the  results  inaccurate. 

The  second  method  is  that  of  Wiley,f  which  is  based  upon  the  theory 
that  boiling  with  an  alkaline  solution  of  mercuric  cyanide  will  destroy  the 
optical  activity  of  maltose  and  dextrose,  leaving  that  of  dextrine  unchanged. 
The  cupric  oxide  reducing  power  of  the  sample  is  ascertained  in  the  usual 
way  by  Fehling's  solution.  The  specific  rotatory  power  is  determined  by 
polarizing  a  ten  per  cent,  solution  (previously  heated  to  boiling)  in  the 
ordinary  manner.  Ten  cubic  centimetres  of  this  solution  used  for  polar- 
izing are  then  treated  with  an  excess  of  an  alkaline  solution  of  mercuric 
cyanide,  and  the  mixture  boiled  for  two  to  three  minutes.  It  is  then  cooled 
and  slightly  acidulated  with  hydrochloric  acid,  which  destroys  the  reddish- 
brown  color  possessed  by  the  alkaline  liquid.  The  solution  is  then  diluted 
to  fifty  cubic  centimetres,  and  the  rotation  observed  in  a  tube  four  decime- 
tres in  length.  The  angular  rotation  observed  will  be  due  simply  to  the 
dextrine,  the  percentage  of  which  may  then  be  calculated  by  the  formula 

rotation  X  1000  X  cubic  centimetres  of  solution  polarized 

198  X  length  of  tube  in  centimetres  X  weight  of  the  sample  taken 
centage  of  dextrine.      The  percentages  of  dextrose  and  maltose  may  be 
deduced  from  the  reducing  power  of  the  sample,  or  from  the  difference  in 
specific  rotatory  power  before  (S)  and  after  (s)  the  treatment  with  alkaline 
mercuric  cyanide.     Thus,  K=l.OO  £  +  .62  m,  £=.527  0  +  139.2  ro  + 

1.98  d  and  «  =  1.98  d,  whence  m=         -f^Icog *  9  can  now  ^e  f°imd 

l.Obo^b 

from  the  first  of  the  three  equations,  and  then  d  in  the  second.  Wiley's 
process  was  employed  by  the  Committee  of  the  National  Academy  of 
Science  in  their  investigation  of  commercial  glucose  from  corn  starch.  It 
is,  however,  based  upon  several  assumptions  that  have  not  been  specifically 
proven,  and  especially  in  the  presence  of  any  considerable  quantity  of 
maltose  are  its  results  open  to  doubt.  (See  Allen,  "  Commercial  Organic 
Analysis/'  3d  ed.,  vol.  i.  p.  369,  foot-note.) 

The  third  method  of  estimating  the  constituents  in  commercial  glucose  is 
due  to  C.  Graham,  and  is  probably  more  exact  than  either  of  those  before 
mentioned.  Dissolve  five  grammes  of  the  sample  in  a  small  quantity  of 
hot  water  and  add  the  solution  drop  by  drop  to  one  litre  of  nearly  absolute 
alcohol.  Dextrine  is  precipitated,  and  on  standing  becomes  attached  to  the 
sides  of  the  beaker,  while  maltose,  gallisin,  and  dextrose  are  soluble  in  the  large 
quantity  of  alcohol  employed.  If  the  solution  be  then  decanted  from  the 
precipitate,  the  dextrine  in  the  latter  can  be  ascertained  by  drying  and  weigh- 
ing, or  by  dissolving  it  in  a  definite  quantity  of  water  and  observing  the 

*  Commercial  Organic  Analysis,  3d  ed.,  vol.  i.  p.  365.  f  Chemical  News,  xlvi.  p.  175. 


182     INDUSTRIES  OF  STARCH  AND  ITS  ALTERATION  PRODUCTS. 

solution,  density,  and  rotation.  The  alcohol  is  distilled  off  from  the  solution 
of  the  sugars  and  the  residual  liquid  divided  into  aliquot  portions,  in  one 
of  which  the  gallisin  may  be  determined  after  fermentation  with  yeast, 
while  others  are  employed  for  the  observation  of  the  specific  rotation  and 
reducing  power,  which  data  give  the  means  of  calculating  the  proportions 
of  maltose  and  dextrose  in  the  sample. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1874. — Die  Starkegruppe,  W.  Nageli,  Leipzig. 

1877. — Die  Chemie  der  Kohlenhydrate,  etc.,  R.  Sachsse,  Leipzig. 

Fortschritte  der  Chemische  Industrie,  A.  W.  Hofmann,  Heft  iii.,  Braunschweig. 
1878. — Traite  theoretique  et  pratique  de  la  Fabrication  du  Sucre,  E.  J.  Maumene,  Paris. 
1879. — Die  Starkefahrikation,  F.  Stohmann,  Berlin. 
1881.— Starch,  Glucose,  and  Dextrine,  Frankel  and  Hutter,  Philadelphia. 

Manual  of  Sugar  Chemistry,  J.  H.  Tucker,  New  York. 
1882. — Foods,  their  Composition  and  Analysis,  A.  W.  Blyth,  London. 

Die  Starke-  und  die  Mahlproducte,  F.  von  Hohnel,  Berlin. 
1884. — Report  on  Glucose  by  the  National  Academy  of  Sciences,  Washington. 
1886.— Die  Starkefabrikation,  Dextrin  und  Traubenzucker,  L.  von  Wagner,  2te  Auf- 
Braunschweig. 

Fabrication  de  1'Amidon,  E.  Guillaume,  Paris. 

Microscopic  der  Nahrungs  und  Genussmittel,  J.  Moller,  Berlin. 
1887. — Die  Fabrikation  der  Starke,  K.  Birnbaum,  Braunschweig. 
1888.— Handbuch  der  Kohlenhydrate,  B.  Tollens,  Breslau. 
1890.— Manual  of  Sugar  Analysis,  J.  H.  Tucker,  3d  ed.,  New  York. 

Traite  d' Analyse  des  Matieres  sucres,  D.  Siderski,  Paris. 

1891. — Die  Untersuchung  Landwirthschaftlieh  wichtiger  Stoffe,  J.  Konig,  Berlin. 
1892.— The  Principal  Starches  used  as  Food,  W.  Griffith,  Cirencester,  England. 
1893. — Introductory  Manual  for  Sugar-Growers,  F.  Watts,  London. 
1894. — Die  Starkefabrikation,  Dr.  B.  von  Posanner,  Wien. 
1895. — Die  Starkefabrikation  und  die  Fabrikation  des  Traubenzucker,  F.  Rehwald,  3te 

Auf.,  Wien. 

1896.— Die  Industrie  der  Starke  in  der  Vereinigten  Staaten,  O.  Saare,  Berlin. 
1897.— Die  Fabrikation  der  Kartaifelstarke,  O.  Saare,  Berlin. 
1900.— Die  Rohstoffe  des  Pflanzenreiches,  J.  Wiesner,  2te  Auf.,  Leipzig. 

STATISTICS. 

1.  PRODUCTION  OF  STARCH  IN  THE  UNITED   STATES  AND  GER- 
MANY.— O.  Saare  in  1896  gave  the  following  summary  of  the  production 
in  these  chief  producing  countries  : 

•United  States.  Germany. 

Hundred  kilos.  Hundred  kilos. 

Potato  starch 120,000  -      180,000  2,000,000  -  3,000,000 

Corn  starch 2,000,000  -  3,000,000  25,000  -        50,000 

Wheat  starch 150,000  -      200,000  50,000  -      100,000 

Kice  starch ...  200,000  -      250,000 

2,270,000  -  3,380,000  2,275,000  -  3,400,000 

2.  PRODUCTION  OF  GRAPE-SUGAR  (STARCH-SUGAR),  GLUCOSE,  DEX- 
TRINE, ETC. — The  same  authority  gives  the  following  figures  for  the  products 
from  starch : 

United  States.  Germany. 

Hundred  kilos.  Hundred  kilos. 

Grape-sugar  and  glucose  syrup  .  2,500,000  -  3,000,000        350,000  -  400,000 
Sugar-color  (caramel)     ...  ...  .  30,000  -     40,000 

Dextrine 20,000  -        50,000        150,000  -  180,000 

2,520,000  -  3,050,000        530,000  -  620,000 


BIBLIOGRAPHY  AND  STATISTICS. 


183 


3.  PRODUCTION  OF  STARCH-SUGAR  IN  FRANCE. — 


1887-88 34,124,079  kilos. 

1888-89 33,439,989     " 

1889-90 39,816,476     » 


1890-91 41,494,243  kilos. 

1891-92 38,223,645     " 

1892-93 38,641,347     " 


4.  EXPORTATIONS 
STATES. — 

Starch  (pounds)    . 

Valued  at   ... 
Glucose  (pounds)  . 

Valued  at   . 


OF  STARCH  AND  GLUCOSE  FROM  THE  UNITED 


1896. 
31,829,435 
$885,198 
171,231,650 
$2,772,335 

1897. 
79,088,876 
$1,665,926 
194,419,250 

$2,736,674 

1898. 
72,806,313 
$1,371,549 
196,864,605 
$2,871,839 

1899. 
110,193,776 
$2,292,843 
229,003,571 
$3,624,890 

184  FERMENTATION   INDUSTRIES. 


CHAPTER  VI. 

FERMENTATION   INDUSTRIES. 

A.  NATURE  AND  VARIETIES  OF  FERMENTATION. 

THE  word  fermentation  in  the  broader  sense  is  applied  to  those  changes 
whereby  in  the  presence  of  a  body  called  a  ferment  many  organic  bodies, 
notably  the  carbohydrates,  are  decomposed  into  simpler  compounds,  although 
not  necessarily  into  the  ultimate  products  of  decomposition. 

The  ferments  which  seem  to  determine  the  decomposition  may  be  either 
soluble  unorganized  ferments,  or  insoluble  organized  ferments,  which  are,  in 
fact,  minute  vegetable  growths.  With  the  soluble  ferments,  such  as  diastase, 
invertin  (or  sucrase),  emulsine,  or  myrosine,  pepsine,  trypsine,  and  papaine, 
which  act  upon  carbohydrates,  glucosides,  and  albuminoids,  we  are  not  now 
concerned,  although  the  first  and  second  of  those  mentioned  play  a  very 
important  part  in  the  hydrolysis  of  starch  and  cane-sugar. 

The  organized  ferments  or  vegetable  growths  may  be  divided  into  three 
classes :  first,  mould-growths ;  second,  yeast-plants,  or  the  different  species 
and  varieties  of  Saccharomyces ;  and,  third,  bacteria,  belonging  to  the  two 
genera  Schizomycetes  and  Schizophycetes.  The  most  important  fermentations 
from  an  industrial  point  of  view  are  the  alcoholic,  which  is  brought  about 
mainly  *  by  the  presence  of  ferments  of  the  second  class,  and  the  acetic  and 
lactic,  which  are  brought  about  by  ferments  of  the  third  class.  Upon  the 
alcoholic  fermentation  depend  three  important  groups  of  industries, — viz., 
the  manufacture  of  malt  liquors,  the  manufacture  of  wines,  and  the  manu- 
facture of  ardent  spirits,  or  distilled  liquors.  Upon  the  acetic  fermentation 
depends  the  manufacture  of  different  varieties  of  vinegar,  and  upon  the 
lactic  fermentation  the  manufacture  of  cheese  and  other  milk  products. 

The  alcoholic  fermentation  is  always  meant  when  we  use  the  word  fer- 
mentation in  the  narrower  sense,  as  with  reference  to  the  change  which 
starch  and  saccharine  bodies  most  generally  undergo.  In  this  fermentation, 
the  action  of  the  yeast-plant  seems  to  differ  according  to  the  variety  of  sugar 
presented  to  it.  Dextrose  is  most  immediately  acted  upon,  the  main  re- 
action being  CgH12O6  =  2C2H6O  +  2CO2,  although,  as  Pasteur  first  showed, 
side-products  like  glycerine  and  succinic  acid  are  also  formed,  and  in  practice 
only  about  ninety-five  per  cent,  of  the  dextrose  is  decomposed  by  the  main 
reaction.  Cane-sugar  is  not  immediately  fermentable.  If  it  has  been 
previously  exposed  to  the  action  of  dilute  acids,  it  is  changed  into  invert 
sugar,  which  then  acts  like  dextrose.  The  yeast-plant  can  effect  the  same 
change  itself.  Invertin  (or  invertase,  as  it  is  also  termed)  is  a  soluble  fer- 
ment existent  in  yeast.  It  has  the  property  of  rapidly  and  completely 
effecting  the  transformation  of  cane-sugar  into  invert  sugar,  but  is  without 

*Buchner  (1897)  has  shown  clearly  that  there  is  present  in  the  yeast-cells,  even  when 
dead,  a  soluble  ferment  or  enzyme  capable  of  developing  the  alcoholic  fermentation. 


NATURE   AND  VARIETIES   OF   FERMENTATION.  185 

sensible  action  on  dextrose,  levulose,  maltose,  or  milk-sugar.  Towards 
dextrine  its  action  is  not  so  certainly  negative. 

The  conditions  of  the  activity  of  the  yeast-plant  have  been  studied  by 
many  chemists,  but  notably  by  Pasteur.  It  has  been  found  that  if  an 
abundance  of  air  is  supplied  the  plant  grows  and  multiplies  but  fermenta- 
tion proceeds  very  slowly,  when  the  supply  of  air  is  limited,  the  fermenta- 
tion proceeds  more  rapidly  while  the  growth  of  the  cells  is  largely~arrested, 
and  that  in  the  absence  of  air  the  fermentation  proceeds  with  greatest 
rapidity,  although  the  plant-cells  do  not  grow  any  longer,  but  gradually 
disintegrate  and  die.  Pasteur's  dictum,  that  "fermentation  is  the  conse- 
quence of  life  without  air,"  is  no  longer  taken  as  strictly  accurate,  as  with 
the  cessation  of  the  growth  and  extension  of  the  yeast-plant  (which  is 
dependent  upon  air  like  the  life  of  any  other  plant),  although  its  fermenta- 
tive activity  then  becomes  greatest,  it  begins  at  the  same  time  a  decay  which 
leaves  it  after  a  time  dead  and  inactive. 

The  genus  Saceharomyces  has  already  been  alluded  to  as  the  active 
agent  in  the  alcoholic  fermentation.  The  species  Saceharomyces  cerevisice 
is  generally  known  as  the  special  beer  ferment  and  the  Saceharomyces 
ellipsoideus  as  the  wine  ferment.  Moreover,  of  the  Saceharomyces  cerevisice, 
two  well-marked  varieties  have  been  recognized.  The  one  is  the  most 
active  at  the  ordinary  temperature  (16°  to  20°  C.),  and  carries  through  its 
fermentative  work  in  from  three  to  four  days ;  the  other  works  at  a  lower 
temperature  (6°  to  8°  C.)  and  the  fermentation  is  much  slower.  The  first, 
placed  in  a  saccharine  liquid,  is  carried  by  the  carbon  dioxide  which  it 
liberates  to  the  surface  of  the  liquid,  where  it  continues  its  activity ;  it  is 
therefore  known  as  a  surface  or  top  yeast.  The  second,  on  the  contrary,  is 
not  carried  up,  and  rests  during  its  entire  activity  on  the  bottom  of  the 
fermenting  vessel,  and  is  hence  called  a  bottom  yeast.  Two  quite  distinct 
methods  of  beer-brewing  are  practised  (see  p.  191),  depending  upon  the  use 
of  the  one  or  the  other  of  these  varieties  of  yeast.  It  has  been  found,  how- 
ever, in  practice  that,  even  when  a  top  yeast  is  used  exclusively  or  a  bottom 
yeast  exclusively,  the  results  are  not  always  uniform.  These  anomalies  are 
now  made  clear  through  the  researches  of  E.  Ch.  Hansen,  of  Copenhagen, 
who  has  applied  the  methods  of  pure  cultivation  introduced  by  bacteriolo- 
gists to  the  study  of  the  yeast-plant.  He  has  found  that  if  a  single  yeast- 
cell  of  one  of  the  better  varieties  of  Saceharomyces  be  cultivated  with  the 
precautions  needed  to  exclude  what  is  called  "  wild  yeast"  (germs  present 
in  the  air,  notably  in  the  summer  months),  absolutely  uniform  results  can 
be  gotten  in  brewing.  Beginning  in  1883,  he  has  developed  the  study,  and 
it  has  now  been  accepted  by  most  of  the  leading  authorities  on  fermenta- 
tion. He  first  described  six  species :  Saceharomyces  cerevisice  I.,  Saceha- 
romyces Pastorianus  I.,  II.,  and  III.,  Saceharomyces  ellipsoideus  I.  and  II., 
of  which  the  second,  fourth,  and  sixth  cause  bitterness  and  turbidity  (so- 
called  "  diseases"  in  beer).  He  has  since  *  increased  the  list  of  varieties 
of  ferments  studied  to  forty,  including  both  top  and  bottom  yeasts,  ferments 
similar  to  yeast  but  not  belonging  to  the  genus  Saceharomyces,  and  forms 
of  mould-growth.  He  divides  the  representatives  of  each  genus  into  two 
groups  according  as  they  secrete  invertin  or  not. 

Fresh  yeast  resembles  a  dirty  yellowish-gray  sediment  of  unpleasant 
odor  and  acid  reaction,  made  up  of  an  immense  number  of  vegetable  cells. 

*  Journ.  Soc.  Chem.  Ind.,  1889,  p.  471. 


186 


FERMENTATION   INDUSTRIES. 


FIG.  60. 


Saccharomyces  cerevisise. 
(After  Hansen.) 


Saccharomyces  cerevisise.    Ascospores. 
(After  Hansen.) 


Saccharomyces  ellipsoideus. 
(After  Hansen.) 


Saccharomyces  ellipsoideus.    Ascospores. 
(After  Hansen.) 


Saccharomyces  Pastorianus. 
(After  Hansen.) 


Saccharomyces  Pastorianus.    Ascospores. 
(After  Hansen.) 


RAW   MATEEIALS. 


187 


FIG.  61. 


YEAST..... 
LACTIC_ 
ACETIC... 


Three  of  the  pure  culture  varieties  of  yeast-plant  as  obtained  by  Hansen 
are  shown  in  the  illustration,  Fig.  60,  together  with  the  special  appearance 
of  the  ascospores  of  the  same.  Of  these,  the  Saccharomyces  cerevisice  and 
Saccharomyces  Pastorianus  are  beer  ferments,  while  the  Saccharomyces  ellip- 
soideus  is  the  wine  ferment.  For  many  purposes  (bread-baking,  use  in  dis- 
tilleries, etc.)  it  is  prepared  as  compressed  yeast  in  cakes,  generally  with  the 
addition  of  potato  starch. 

The  special  conditions  of  the  alcoholic  fermentation  are :  first,  an 
aqueous  solution  of  sugar  of  the  strength  of  one  part  sugar  to  four  to 
ten  parts  water;  second,  the 
presence  of  a  yeast  ferment. 
If  this  is  not  added  already  de- 
veloped and  active,  or  if  the 
fermentation  is  to  be  sponta- 
neous,— that  is,  brought  about 
by  spores  from  the  air, — the 
conditions  for  the  development 
of  these  spores  must  also  be 
present.  There  must  be  protein 
compounds  and  phosphates  of 
the  alkalies  and  alkali  earths. 
Thirdly,  the  temperature  must 
remain  within  the  limits  5°  to 
30°  C.,  or,  more  generally,  from 
9°  to  25°  C.  Above  30°  C.  the 
alcoholic  fermentation  readily 
passes  into  the  butyric  and  other 
decomposition. 

The  effect  of  temperature 
upon  the  several  different  fer- 
ments is  shown  in  the  graphic 
illustration  of  Fig.  61,  which 
represents  also  the  influence  of 
temperature  upon  the  decom- 
position of  starch  by  diastase. 
On  the  right  side  of  the  figure, 

the  regularly-dotted  line  represents  the  yeast  curve.  A  slight  fermentation 
is  already  induced  at  a  temperature  very  little  over  the  melting  point  of  ice. 
As  the  temperature  rises  its  activity  increases  until  the  maximum  is  reached, 
at  about  33°  C.  (92°  F.),  when  it  diminishes  down  to  nothing  again,  and  at 
50°  C.  (122°  F.)  or  thereabouts  it  is  killed.  The  activity  of  the  acetic  fer- 
ment is  repeated  at  the  same  time  by  the  irregularly-dotted  line,  and  that  of 
the  lactic  ferment  by  the  uniform  black  line. 

B.  MALT  LIQUORS  AND  THE  INDUSTRIES  CONNECTED  THEREWITH. 
I.  Raw  Materials. 

1.  MALT. — Malt  is  prepared  by  steeping  barley  or  other  grain  in  water, 
and  allowing  it  to  germinate  in  order  to  change  the  character  of  the  albumi- 
noids and  develop  the  ferment  diastase,  which  then  begins  to  act  upon  the  starch, 
the  germination  and  change  being  stopped  at  a  certain  stage  by  heating  in 
a  kiln.  The  composition  of  the  unmalted  barley  was  given  among  other 


GRAIN   MASH. 
POTATO    MASH 
ENGLISH   BEER. 

LA6ER   ACER 


188  FERMENTATION   INDUSTRIES. 

cereals  on  p.  169.  The  changes  which  it  undergoes  in  composition  by  the 
process  of  malting  will  be  seen  by  comparing  this  with  the  two  analyses  of 
pale  malt  following,  which  are  by  O'Sullivau : 

No.  I.  No.  II. 

Starch 44.15  45.13 

Other  carbohydrates  (of  which  sixty  to  seventy  per  cent,  consist  of  fer- 
mentable sugar),  inulin  and  similar  bodies  soluble  in  cold  water 21.23  19.39 

Cellular  matter         11.57  10.09 

Fat 1.65  1.96 

Albuminoids  soluble  in  water 6.71  5.31 

Albuminoids  insoluble  in  water 6.38  8.49 

Ash 2.60  1.92 

Water                                       .    .    .                                                                          5.83  7.47 


100  00      100.00 

O'Sullivan  states  that  malt  contains  no  ready-formed  dextrine,  but  that 
it  does  contain  from  sixteen  to  twenty  per  cent,  of  fermentable  sugars,  of 
which  about  one-half  is  probably  maltose,  and  due  to  the  transformation  of 
starch  in  the  malting  process,  while  the  remainder  exists  ready  formed  in 
the  barley,  and  is  not  identical  with  the  sugar  produced  in  the  malting. 

Besides  the  diastase,  a  second  soluble  ferment  is  formed  during  the  malt- 
ing process,  the  so-called  peptase,  which  in  the  mash  process  changes  the 
proteids  of  the  malt  into  peptones  and  parapeptones,  which  give  nutritive 
value  to  the  beer. 

A  high  percentage  of  starch  in  the  barley  to  be  used  for  brewing  is 
desirable  in  order  that  when  malted  it  may  yield  a  large  amount  of  "  extrac- 
tive matter."  According  to  Lintner  and  Aubry,*  a  good  malt  should  yield 
at  least  seventy-one  per  cent,  of  extract  reckoned  on  the  weight  of  dry 
substance.  This  determination  of  the  value  of  a  sample  of  malt  is  one  of 
the  most  necessary  of  analytical  tests  for  the  malster  or  brewer.  (See  p.  197.) 

Well-malted  barley  is  always  yellow  or  amber-colored,  shading  to  brown. 
On  breaking  the  grain,  the  interior  should  be  of  a  pure  white  color  and 
floury  appearance,  except  when  the  drying  has  been  intentionally  carried  so 
far  as  to  partially  caramelize  the  sugar. 

Malted  wheat,  corn,  and  rice  are  at  times  used  as  partial  substitutes  for 
the  barley  malt,  as  well  as  potato  starch  and  starch-sugar.  The  use  of 
patented  maltose  and  maltose-dextrine  preparations  has  already  been  referred 
to.  (See  p.  175.) 

2.  HOPS. — Hops  are  the  female  unfructified  blossoms  (catkins)  of  the 
hop-plant  (Humulus  lupulus).  Under  the  thin  membranous  scales  of  the 
strobile  or  catkin  is  an  abundance  of  a  yellowish  resinous  powder,  consist- 
ing of  minute  sessile  grains,  to  which  the  name  lupulin  has  been  given.  The 
active  principles  of  the  hops,  contained  mainly,  but  not  exclusively,  in  the 
lupulin,  are :  First,  the  ethereal  oil,  which  is  present  to  the  amount  of  .3 
per  cent,  in  the  air-dried  hops.  This  is  yellowish,  of  strong  odor  and  of 
burning  taste.  It  consists  of  a  hydrocarbon,  C5H8,  and  an  oxygenized  oil, 
C10H18O2,  which  by  atmospheric  oxidation  becomes  valerianic  acid,  C5H10O2, 
to  which  old  hops  owe  their  odor.  Second,  the  lupulin  also  contains  a  resin- 
ous bitter  principle,  which  is  easily  soluble  in  alcohol,  but  difficultly  solu- 
ble in  water,  and  extremely  bitter.  This  is  supposed  to  be  an  oxidation 
product  of  lupulinic  acid,  which  can  be  gotten  in  white  crystals,  speedily 
becoming  resinous.  Both  the  acid  and  its  oxidation  products  seem  to  be 

*  Jahresber.  Chem.  Tech.,  1882,  pp.  840  and  851. 


PROCESSES   OF   MANUFACTURE. 


189 


held  dissolved  in  the  ethereal  oil.  Hops  also  contain  tannic  acid  of  a 
variety  allied  to  moritannic  acid  and  turning  iron  salts  green.  Analyses  of 
two  well-known  Bohemian  varieties  of  hops  are  given.* 


1 

4 

g 

Residue  from 

si 

fl 

•§   • 

"3 

i 

alcohol  solu- 

oS 

o 

^H 

ble  in  water. 

•S  t5 

i^ 

o  S 

PERCENTAGE  COMPOSITION. 

O> 

•§ 

oS  v 
c2 

?A- 

-ob 

<D 

"3 

3 

11 

o 

•§ 

Organ- 
ic. 

Ash. 

p 

oi  ^i 

O  i 

Ifi 

•d 

td 

f 

W 

dj 

o 

H§^ 

^ 

u 

(M 

From  Saatz                          . 

990 

013 

20  12 

14  57 

11  24 

5  42 

2  52 

10  01 

871 

0  91 

From  Auscha    

10.61 

0.17 

20.97 

15.14 

10.51 

5.10 

3.18 

7.87 

9.51 

0.81 

The  blossoms  are  produced  in  August,  and  the  strobiles  are  fit  for  gath- 
ering from  the  beginning  of  September  to  the  middle  of  October,  according 
to  the  weather.  The  prompt  drying  of  the  fresh-picked  hops  is  necessary 
in  order  that  they  may  be  safely  baled.  This  drying  takes  place  by  the  aid 
of  hot  air  in  a  so-called  hop-kiln  at  a  temperature  of  about  40°  C.,  the  hops 
being  repeatedly  turned  with  a  light  wooden  shovel  as  they  lie  spread  out 
upon  a  false  or  perforated  floor.  When  dry  they  are  pressed  by  hydraulic 
presses  into  compact  bales.  Hops  are  also  often  treated  with  sulphurous 
acid  gas  from  burning  sulphur  to  preserve  them,  although  this  sulphuring 
is  oftener  used  with  old  hops  for  the  purpose  of  brightening  them  in  color 
and  improving  their  appearance. 

A  number  of  bitter  principles  have  been  mentioned  as  used  at  times  as 
substitutes  for  hops  in  beer-brewing,  although  it  is  doubtful  if  such  substitu- 
tion is  much  practised.  Among  these  substitutes  have  been  noted  quassia, 
gentian,  picrotoxin,  the  bitter  principle  of  Cocculus  Indicus,  colchicum, 
wormwood,  and  picric  acid. 

3.  WATER.—The  water  used  in  malting  and  brewing  must  be  adapted 
for  the  purpose  in  order  to  get  good  results.  A  pure  and  soft  water  or  a 
moderately  hard  calcareous  water  will  do,  but  it  is  indispensable  that  the 
water  be  perfectly  free  from  organic  impurities.  Continental  brewers  use 
soft  waters  most  generally  in  brewing  beers,  while  English  brewers  prefer 
gypsum  waters  for  their  ales  which  are  specially  designed  to  keep.  This  is 
shown  in  the  character  of  the  water  of  Burton-on-Trent,  which  contains 
notable  quantities  of  calcium  and  magnesium  sulphates,  calcium  carbonate,  and 
sodium  chloride. 

II.  Processes  of  Manufacture. 

1.  MALTING  OF  THE  GRAIN. — Although  malt  has  been  described  as 
a  raw  material  of  the  brewing  industry,  the  preparation  of  it  from  the  raw 
grain  is  a  process  so  closely  connected  with  the  success  of  brewing  that  it 
must  be  described,  and  especially,  too,  because  it  is  often  combined  under  the 
same  direction  as  the  brewing  process.  The  process  of  changing  barley  into 
malt  is  to  be  divided  into  four  stages :  the  steeping,  the  couching,  the  floor- 
ing, and  the  kiln-drying.  The  first  three  of  these  stages  have  to  do  with 
the  germination  or  development  of  the  acrospire,  or  plumule,  which  as  it 
develops  brings  about  great  changes  in  the  chemical  constitution  of  the  grain, 
developing  from  the  albuminoid  matter  the  diastase,  which  in  turn  begins  to 


*  Konig,  Nahrungs-  und  Genussmittel,  vol.  ii.  p.  409. 


190  FERMENTATION   INDUSTRIES. 

act  upon  the  starch,  forming  from  it  maltose  and  dextrine.  At  the  same 
time  during  the  germination  atmospheric  oxidation  is  going  on  at  the  expense 
of  the  starch  of  the  grain,  water  and  carbon  dioxide  being  steadily  given  off. 
When  the  development  of  the  diastase  is  supposed  to  have  reached  the  right 
point,  which  can  only  be  judged  of  by  the  growth  of  the  acrospire,  or  germ, 
the  fourth  stage  of  the  process  is  reached,  and  the  germ  must  be  killed  by 
heat,  which  is  done  in  the  kiln-drying. 

The  first  process  of  steeping  is  to  give  the  grain  sufficient  moisture  to 
allow  germination  to  begin.  For  that  purpose  it  is  put  into  wooden,  iron, 
or  cemented  vats.  These  are  half  filled  with  water  and  the  grain  added 
with  constant  stirring.  The  sound  grains  sink  shortly  under  the  water,  and 
the  dead  or  imperfect  grains  float  and  can  be  removed.  The  water  soon 
takes  color  and  odor,  and  must  be  replaced  by  fresh  water.  The  duration 
of  the  steeping  is  usually  forty-eight  to  seventy-two  hours,  depending  upon 
the  temperature,  and  in  winter-time  or  with  older  barley  may  last  consider- 
ably longer.  The  end  of  the  treatment  may  be  told  by  noting  the  character 
of  the  grain.  It  has  swollen  and  become  nearly  sufficiently  soft  to  allow  of 
being  pierced  with  a  needle  and  yet  exuding  no  juice.  It  has  gained  from 
forty  to  fifty  per  cent,  in  weight  and  increased  from  twenty  to  twenty-four 
per  cent,  in  bulk.  To  offset  this  gain  due  to  water  absorption,  it  has  lost 
from  one  to  two  per  cent,  of  its  substance,  partly  carried  off  in  the  steep 
water  and  partly  given  off  as  gas.  The  water  is  then  run  off,  and  after 
draining  it  is  turned  upon  the  couch  ing-floor,  where  it  remains  at  first  in 
heaps  of  from  fifteen  to  twenty-four  inches  in  depth.  Here  it  soon  begins 
to  heat  up,  and  a  rise  in  temperature  of  from  7°  to  10°  takes  place.  It  also 
begins  to  "  sweat,"  and  gives  off  an  abundance  of  carbon  dioxide,  and  an 
agreeable  cucumber-like  odor  is  recognizable.  The  germination  is  now  under 
way  and  the  rootlets  shoot  out.  The  "  couching"  stage  lasts  from  twenty- 
four  to  thirty-six  hours,  and  during  that  time  the  grain  must  be  turned 
several  times.  The  heated  barley  must  now  be  spread  on  the  floor  in  shal- 
low layers  so  as  to  check  somewhat  the  rate  of  growth  of  the  germ,  and 
must  be  turned  from  four  to  six  times  a  day  as  the  growth  proceeds.  The 
depth  of  the  layer  is  at  the  same  time  reduced  from  fifteen  to  four  or  five 
inches.  During  this  time  the  germinating  grain  must  have  an  abundance  of 
air.  The  process  lasts  from  seven  to  ten  or  even  twelve  days,  according  to 
the  season  of  the  year,  and  its  termination  is  decided  by  the  length  of  the 
germ,  which  must  be  about  two-thirds  that  of  the  grain.  The  loss  in  weight 
during  the  germinating  process,  according  to  Lintner,  is  ten  per  cent,  of  the 
weight  of  the  grain.  The  loss  comes  mainly  upon  the  starch,  which  has  in 
part  been  changed  into  maltose  and  dextrine,  but  has  mostly  been  oxidized  to 
water  and  to  carbon  dioxide.  To  more  efficiently  remove  the  carbon  dioxide 
which  would  interfere  with  the  germinating  process  and  to  prevent  too  strong 
a  heating,  the  pneumatic  process  of  malting  has  been  proposed  by  Galland.  In 
this  process  the  steeped  barley  is  placed  on  a  perforated  floor  in  thick  layers, 
and  a  regulated  current  of  moist,  well-cooled  air  is  kept  passing  through  it. 
This  process  is  now  replacing  the  other  quite  largely.  Still  another  form 
of  mechanical  malting  apparatus  is  that  of  Saladin.*  The  germination 
must  now  be  stopped  promptly,  lest  it  go  too  far  at  the  expense  of  the 
starch  of  the  grain,  and  this  is  best  effected  by  heat.  The  germinating 
grain  may,  however,  be  simply  dried  thoroughly  in  the  air  and  the  rootlets 

*  Dammer's  Handbuch  der  Chemischen  Technologie,  vol.  iii.  p.  632. 


PROCESSES   OF  MANUFACTURE.  191 

removed  by  mechanical  means.  This  constitutes  air-dried  malt,  which  is 
used  for  some  purposes.  Most  generally  it  is  dried  in  a  kiln  at  a  consider- 
ably higher  temperature.  This  must  be  gradually  applied,  as  if,  while  the 
raw  malt  were  full  of  moisture,  it  were  to  be  heated  strongly,  the  starch 
would  be  gelatinized  and  the  grain  made  tough,  hard,  and  glassy.  It  is 
therefore  heated  first  to  about  90°  F.,  and  this  is  gradually  raised  to  150°  F., 
or  even  in  some  cases  to  180°  F.  A  light  gradual  heat  produces  a  "  pale" 
malt,  a  stronger  heat  "  yellow"  or  "  pale  amber,"  and  then  "  amber"  and 
"  brown"  malt.  The  kiln  may  have  two  floors,  on  the  upper  and  cooler  of 
which  the  moist  malt  loses  its  water  and  then  passes  on  to  the  lower  and 
hotter  floor,  where  it  is  heated  to  the  higher  limit  requisite  for  developing  its 
empyreumatic  odor  and  flavor,  or  the  heating  may  all  be  effected  on  a  single 
floor,  in  which  case  more  time  is  needed  for  the  several  stages  of  heating. 
Black  malt  used  for  coloring  is  heated  in  revolving  coffee-roasters,  and  most 
of  the  sugar  is  caramelized. 

2.  PREPARATION  OF  THE  WORT. — The  malt  after  being  cleansed  and 
crushed  (not  ground  fine)  is  ready  for  use  in  what  is  known  as  the  mashing 
process.  This  is  designed  not  merely  to  extract  the  maltose  and  dextrine 
of  the  malt,  but  mainly  to  allow  the  diastase  of  the  malt  to  act  upon  the 
starch,  changing  it  into  maltose  and  dextrine  and  the  peptase  to  form  pep- 
tones from  the  proteids.  It  must  therefore  be  carried  out  under  such  con- 
ditions of  temperature  and  dilution  as  have  been  found  to  be  most  favorable 
for  effecting  these  purposes.  We  have  already  seen  (p.  187)  that  the  action 
of  diastase  is  most  effective  at  about  62.5°  C.  (144.5°  F.),  and  therefore  at 
a  temperature  not  much  above  this  is  the  infusion  most  successfully  made. 
At  a  temperature  of  over  75°  C.  its  power  is  destroyed.  Two  quite  distinct 
processes  for  mashing  are  at  present  followed :  the  infusion,  or  thin  mash, 
and  the  decoction,  or  thick  mash,  process.  The  first  is  used  in  England  and 
France,  the  second  in  Bavaria,  Bohemia,  and  the  principal  brewing  centres 
of  the  Continent.  Both  are  used  in  this  country.  In  the  infusion  process, 
water  at  60°  to  70°  C.  is  run  into  the  mash-tub,  a  vessel  provided  with  false 
bottom  and  mechanical  agitation,  the  crushed  malt  added  and  stirred  in,  and 
then  additional  hotter  water,  so  that  a  temperature  of  70°  C.  (158°  F.)  is 
gradually  attained.  This  is  maintained  for  some  time  with  constant  agita- 
tion of  the  liquid,  so  that  the  diastase  may  have  time  to  act  upon  the  starch. 
The  completion  of  this  action  is  determined  by  taking  a  few  drops  of  the 
wort  from  time  to  time  and  testing  with  iodine  solution,  which  finally  pro- 
duces no  color  on  mixing.  The  clear  infusion  is  now  run  off  from  under 
the  false  bottom  of  the  tub  to  the  copper  boilers,  and  the  malt  again  covered 
with  hot  water  and  mashed  for  one-half  to  one  hour  longer  at  70°  C.  or 
somewhat  higher  now.  When  this  is  run  off,  hot  water  at  200°  F.  is 
sprinkled  upon  the  malt  from  a  revolving  "  sparger"  and  allowed  to  drain 
off.  The  wort  from  this  third  mash  is  not  always  added  to  that  of  the  first 
and  second  mashes,  but  is  used  to  mash  a  fresh  quantity  of  malt. 

In  the  Bavarian  thick-mash  process,  the  malt  is  put  in  the  mash-tub 
with  some  cold  water,  and  then  by  the  addition  of  boiling  water  is  brought 
to  35°  C.  A  third  of  the  softened  malt  is  then  taken  out  and  brought 
gradually  to  boiling  with  water  in  the  copper.  After  one-half  to  three- 
quarters  of  an  hour's  boiling,  the  half  of  this  is  then  returned  to  the  mash- 
tub  and  thoroughly  agitated  with  what  remained  there.  The  temperature 
of  the  mash-tub  is  thereby  brought  to  about  50°  C.  A  second  portion 
of  the  thick  mash  is  again  taken  out  and  boiled  in  the  copper  for  three- 


192  FERMENTATION   INDUSTRIES. 

quarters  to  one  hour,  when  the  greater  part  is  returned  to  the  mash-tub 
and  thoroughly  mixed,  bringing  up  the  temperature  here  to  65°  C.  The 
thinner  part  of  the  mash,  or  clear  wort,  is  now  run  off  and  boiled  in  the 
copper  for  fifteen  minutes  and  returned,  whereby  the  temperature  of  the  mash- 
tub  is  brought  to  75°  C.  This  is  now  left  at  rest  for  an  hour  to  an  hour 
and  a  half,  and  then  the  wort  is  run  off  to  the  copper.  The  malt  is 
washed  by  the  sparger,  and  so  the  saccharine  liquor  adhering  displaced. 
The  whole  process  is  easily  understood  by  reference  to  Fig.  62,  in  which  A 
is  the  mash-tub  and  C  the  copper  for  boiling  up  the  successive  portions 
taken  from  A. 

It  is  obvious  that  in  the  thick-mash  process  that  portion  of  the  diastase 
contained  in  the  material  which  is  taken  out  and  boiled  is  destroyed,  but  the 
boiling  thoroughly  disintegrates  the  malt  and  converts  its  starch  into  a 

rte.  When  this  is  returned  to  the  mash-tub,  it  is  very  rapidly  acted  upon 
the  remaining  diastase,  of  which  tjiere  is  quite  sufficient,  and  changed 
into  maltose  and  dextrine.  By  the  thick-mash  process,  the  sugar  formation 
is  held  in  check  and  the  amount  of  extract  increased. 

In  the  mash  process  the  diastase  acts  upon  the  starch  of  the  malt, 
changing  it  into  maltose  and  dextrin.  The  ratio  of  these  products  to  each 
other  changes  according  to  the  temperature  used  in  the  mashing.  More- 
over, as  dextrin  is  not  fermented  in  the  main  fermentation  and  only  par- 
tially in  the  after- fermentation,  some  of  it  remaining  in  the  finished  beer, 
this  matter  of  temperature  of  mashing  is  obviously  of  importance  for  the 
character  of  the  beer. 

According  to  Marker  and  Schultze,  at  temperatures  up  to  65°  C.  the 
reaction  takes  place  as  follows : 

4C6H1006  +  2H20  =  0,^0,,  +  C6H1006; 

that  is,  four  molecules  of  starch  react  with  two  molecules  of  water  to  form 
three  molecules  of  fermentable  sugar  (maltose)  and  one  molecule  of  dextrin. 
On  the  other  hand,  at  temperatures  over  65°  C.,  the  reaction  becomes — 

6(^H,,05  +  2H20  =  C18H310,7  +  3C6H,A; 

that  is,  six  molecules  of  starch  react  with  two  molecules  of  water  to  form 
one  molecule  of  maltose  and  three  molecules  of  dextrin. 

The  results  of  practice,  at  all  events,  show  that  in  the  infusion  process, 
which  takes  place  at  low  temperatures,  beers  of  lower  extract  percentage 
are  formed  which  is  in  part  due  to  this  difference  in  the  production  of 
dextrin  just  illustrated.  A  second  drawback  of  the  infusion  process  is  that 
it  is  difficult  to  avoid  here  a  larger  formation  of  lactic  acid,  due  to  the  more 
prolonged  action  of  the  water  upon  the  malt,  which  is  at  just  the  tempera- 
ture (about  50°  C.)  favorable  for  the  formation  of  lactic  acid.  At  the 
temperature  of  the  infusion  process  the  nitrogenous  compounds  are  also 
less  completely  decomposed  than  in  the  decoction  process,  so  that  a  beer 
obtained  by  the  former  process  furnishes  a  more  nutritious  ground  for  the 
growth  of  bacterial  ferments  than  the  latter. 

As  the  amount  of  diastase  in  the  malt  is  sufficiently  large  to  saccharify 
considerably  more  starch  than  that  contained  in  the  malt  itself,  at  times 
unmalted  grain  and  starch-containing  cereals  are  added.  The  end  to  be 
attained  is  not  only  the  saving  of  the  cost  of  a  portion  of  the  malt,  but 
to  obtain  a  beer  richer  in  extract  and  therefore  of  better  keeping  quality. 


PROCESSES  OF   MANUFACTURE. 


193 


FIG.  62. 


13 


194  FERMENTATION  INDUSTRIES. 

These  malt  substitutes  are  generally  cereals  rich  in  starch,  such  as  corn 
and  rice.  At  times  unmalted  barley,  rye,  oats,  and  even  potatoes  have  also 
been  used.  Care  must  be  taken  that  the  saccharin  cation  in  these  cases  of 
the  use  of  corn  and  rice  is  made  as  complete  as. possible,  and  hence  it  must 
not  be  overlooked  that  the  starch  of  both  corn  and  rice  requires  a  higher 
temperature  (71°  C.)  for  its  complete  changing  into  fermentable  sugar. 
The  corn  or  rice  before  use  should  be  shelled,  deprived  of  the  germ,  and 
crushed,  so  as  to  facilitate  the  liberation  of  its  starch.  The  amount  of  malt 
substitute  thus  used  should  not  in  any  case  exceed  thirty  per  cent,  of  the 
weight  of  the  malt.  In  some  countries,  as  in  Bavaria,  the  use  of  malt 
substitutes  is  strictly  prohibited  by  law. 

The  character  of  the  wort  is  to  be  controlled  by  the  use  of  the  Bal- 
ling saccharometer  (see  p.  163),  as  the  specific  gravity  of  aqueous  malt 
extract  corresponds  to  that  of  cane-sugar  solutions  of  the  same  percentage 
strength. 

3.  BOILING  AND  COOLING. — The  wort  is  drained  off  from  the  malt- 
residue,  or  "  draff,"  and  run  into  the  copper  boiler,  where  it  is  boiled,  while 
the  hops  are  added  at  once  in  amount  varying  from  one  to  three  (or  more  in 
the  case  of  India  ales)  parts  to  the  hundred  of  malt,  light  beers  taking  the 
least  amount,  lager  beers  next,  and  heavy  export  beers  the  largest  amount. 
If  the  amount  of  hops  is  to  be  calculated  after  the  wort  has  been  formed, 
0.25  to  0.30  kilos,  may  be  taken  to  the  hectolitre  of  wort  of  10  to  12  per 
cent.,  0.40  to  0.60  kilos,  to  the  hectolitre  of  wort  of  12  to  15  per  cent.,  and 
0.70  to  0.80  kilos,  to  the  hectolitre  of  stronger  worts. 

The  boiling  accomplishes  several  desirable  changes  in  the  wort :  first, 
the  protein  material  present  is  coagulated  and  separates  out,  which  result  is 
facilitated  by  the  action  of  the  tannic  acid  of  the  hops,  which  also  throws  out 
any  unchanged  starch  ;  second,  the  wort  is  concentrated  ;  third,  the  valuable 
constituents  of  the  hops  (hop-bitter  and  ethereal  oil)  are  taken  up  by  the  wort 
and  give  to  the  beer  its  taste,  aroma,  and  keeping  qualities.  The  time  of 
boiling  varies  considerably,  requiring  to  be  longer  for  worts  prepared  by  the 
infusion  process  than  for  those  by  the  decoction  process.  From  one  to  two 
hours  is  generally  sufficient  where  the  worts  do  not  specially  need  to  be  con- 
centrated. Too  long  boiling  is  injurious,  as  the  volatile  oil  of  the  hops 
may  be  lost  thereby.  Of  one  hundred  parts  of  dry  malt,  sixty-five  to 
eighty  per  cent,  are  taken  up  as  extract  in  the  wort ;  of  one  hundred  parts 
of  hops,  twenty  to  thirty  parts. 

The  wort  is  now  to  be  cooled  preparatory  to  the  fermentation.  This 
cooling  must  be  effected  as  rapidly  as  possible,  so  that  the  lactic  fermenta- 
tion and  similar  changes  may  not  take  place.  The  cooling  is  generally 
effected  in  very  shallow  wide  tanks,  which  are  placed  where  a  good  circula- 
tion of  air  can  be  assured.  From  these  tanks  the  still  warm  wort  is  often 
run  through  a  circuit  of  pipes  cooled  by  ice-water  flowing  around  them,  or 
is  run  in  thin  streams  (known  as  a  "  beer  fall' )  over  a  series  of  pipes  through 
which  cold  water  or  chilled  brine  from  the  refrigerating  apparatus  circulates. 
Such  an  arrangement  is  now  coming  into  extensive  use  in  large  breweries 
provided  with  artificial  refrigeration.  Of  course,  in  such  a  method  of  cool- 
ing the  wort  is  exposed  for  a  considerable  time  to  impure  air  containing 
spores,  which,  getting  into  the  liquid,  may  afterwards  affect  the  fermentation. 
In  all  cases  where  Hansen's  pure  yeast  is  to  be  employed  the  wort  must  be 
cooled  in  vessels  to  which  only  sterilized  air  lias  access.  For  an  arrange- 
ment of  this  kind,  see  Wagner's  "Chemical  Technology,"  13th  ed.,  p.  911. 


PROCESSES   OF  MANUFACTURE.  195 

It  is  thus  cooled  down  to  the  point  needed  for  the  beginning  of  the  fermenta- 
tion. This  point  depends  upon  the  character  of  the  fermentation,  whether 
with  top  yeast  or  bottom  yeast ;  for  the  latter  it  must  be  some  8°  to  10°  C. 
below  that  needed  for  the  former.  The  cooled  wort  is  now  allowed  to 
deposit  a  sediment  of  coagulated  albuminoids,  particles  of  hops,  etc.,  which 
were  suspended  in  it  when  the  cooling  began.  This  sediment  is  gathered 
and  pressed  and  the  liquid  added  to  the  rest  of  the  wort. 

4.  FERMENTATION  OF  THE  WORT.— The  wort  may  either  be  left  to 
spontaneous  fermentation  depending  upon  the  spores  of  yeast  ferments, 
which  are  always  present  in  the  air  of  a  brewery,  or  it  is  started  into  fer- 
mentation by  the  addition  of  yeast.  The  former  method  is  followed  in 
Belgium,  but  in  the  great  majority  of  cases  elsewhere  fermentation  is  incited 
by  the  direct  addition  of  a  suitable  yeast.  As  stated  before  in  the  section 
on  the  nature  of  fermentation  (see  p.  185),  there  are  two -radically  different 
methods  of  carrying  out  this  process  in  practice :  the  surface  fermentation 
and  the  bottom  fermentation.  The  first  of  these,  followed  almost  exclu- 
sively in  England  for  all  malt  liquors  and  in  this  country  for  ales,  is  spe- 
cially adapted  for  worts  rich  in  maltose,  and  takes  place  more  rapidly,  at  a 
higher  temperature,  and  produces  more  alcohol.  As  English  worts,  more- 
over, are  usually  prepared  by  the  infusion  method,  a  considerable  quantity 
of  soluble  gluten  is  left  in  the  liquor,  which  on  exposure  to  the  air,  as  in 
half-empty  casks,  may  start  the  acetic  fermentation,  or  souring.  The  second 
of  these,  followed  in  Germany  and  Austria  and  in  this  country  for  lager- 
beer,  proceeds  more  slowly ;  the  production  of  alcohol  is  restrained  by  the 
low  temperature,  and  as  the  fermentation  proceeds  with  freer  and  more 
prolonged  access  of  air,  the  yeast-plants  in  their  growth  consume  the  pro- 
teid  matter  as  food.  Consequently  there  is  less  albuminoid  matter  left  to 
start  souring,  and  the  beer  is  a  better-keeping  beer  than  those  prepared  by 
the  more  rapid  surface  fermentation.  Of  course,  the  proportion  of  malt 
and  hops  used  and  the  alcohol  percentage  also  come  into  consideration  in 
the  matter  of  keeping  quality,  and  may  offset  the  advantage  just  mentioned. 
The  fermentation,  by  whichever  method  carried  out,  may  be  divided  into 
three  stages :  first,  the  main  fermentation,  which  begins  shortly  after  the 
addition  of  the  yeast,  and  is  specially  characterized  by  the  decomposition 
of  maltose,  the  formation  of  new  yeast-cells,  and  the  rise  of  temperature ; 
second,  the  after-fermentation,  in  which  the  decomposition  of  maltose  still 
continues,  but  the  formation  of  yeast-cells  has  nearly  ceased,  and  the  yeast 
particles  suspended  in  the  beer  settle  out  and  the  beer  clears ;  and,  third, 
the  still  fermentation,  which  follows  the  completed  after-fermentation,  in 
which  maltose  is  still  decomposed  and  some  dextrine  is  changed  into  maltose 
by  what  diastase  is  present,  but  the  yeast-cells  are  no  longer  formed. 

The  fermenting  vessels  are  great  oaken  tuns  holding  fifty  to  one  hundred 
barrels.  The  thick  froth,  or  magma,  of  yeast  is  added  in  amount  varying 
from  one-half  to  three-quarters  of  a  litre  per  one  hundred  litres  of  wort 
of  ten  to  fourteen  per  cent.  It  may  either  be  added  direct  to  the  whole 
body  of  the  wort  and  stirred  in,  or  may  be  mixed  with  a  smaller  amount 
of  the  wort,  allowed  to  stand  for  four  to  five  hours  until  fermentation 
starts,  and  then  the  mixture  added  to  the  main  body  of  the  wort.  In  the 
surface  fermentation  process,  the  main  fermentation  lasts  from  four  to  eight 
days,  during  which  time  the  temperature  must  be  carefully  regulated  and 
held  at  from  14°  to  18°  C.  The  surface  is  at  first  covered  with  a  white 
foam  which  rises,  and  curls  and  breaks  into  a  variety  of  forms.  The 


196  FERMENTATION   INDUSTRIES. 

temperature  rises  from  two  to  four  degrees,  and  care  must  be  taken  to  con- 
trol and  reduce  this,  which  used  to  be  done  by  the  use  of  conical  cans,  or 
"  swimmers,"  holding  ice,  floated  at  the  top  of  the  tun,  cooling  the  mass, 
but  the  tuns  are  now  cooled  just  as  the  fermenting  cellars  are,  by  arti- 
ficial means.  The  fermentation  is  not  allowed  to  go  to  completion  at  this 
initial  temperature,  but  the  beer  is  transferred  for  the  after  or  slower  fer- 
mentation to  cooler  cellars  (of  about  5°  C.),  where  it  is  put  into  storage- 
casks.  After  sufficient  time  here,  it  is  drawn  into  casks  containing  beech- 
wood  shavings,  to  which  isinglass  is  sometimes  added  to  clear  it,  and  there 
is  added  to  it  some  fresh  fermenting  beer  (u  Krausen"),  in  the  proportion 
of  one  barrel  to  twenty,  which  starts  a  new  fermentation,  giving  the  beer  its 
"  head."  In  the  bottom  fermentation,  the  fermenting  cellar  is  kept  at  4° 
to  5°  C.,  and  the  main  fermentation  lasts  from  nine  to  ten  days.  The  after- 
fermentation  follows  in  cellars  cooled  to  1°  to  2°  C.,  and  lasts  correspond- 
ingly longer. 

Berlin  weiss-beer  is  brewed  from  malted  wheat  to  which  some  malted 
barley  is  added,  and  is  fermented  at  relatively  higher  temperature  (16°  to 
24°  C.).  At  the  end  of  the  main  fermentation,  which  is  finished  in  three 
days,  it  is  transferred,  with  the  addition  of  some  fresh  fermenting  beer,  to 
tightly-stopped  stone  jugs,  in  which  the  after-fermentation  takes  place. 
In  eight  to  fourteen  days  it  is  in  condition  for  drinking.  It  is,  of  course, 
effervescing,  is  somewhat  turbid,  and  has  a  sour  taste  from  lactic  acid  which 
has  formed. 

5.  PRESERVATION  OF  BEER. — Beer  or  ale  intended  for  export  may  of 
course  have  keeping  qualities  imparted  to  it  in  its  manufacture  by  special 
addition  of  hops,  or  otherwise,  but  most  beers  can  have  their  keeping 
qualities  improved  by  direct  treatment  after  they  are  finished  beverages. 
This  is  most  legitimately  done  by  the  process  of  "  Pasteurizing,"  which 
consists  in  heating  the  beer  either  already  bottled  or  in  casks  to  a  tempera- 
ture of  about  60°  C.,  which  apparently  kills  all  ferments  which  develop 
.the  souring  of  beer.  Less  legitimate  and  forbidden  by  law  in  many 
countries  is  the  addition  of  salicylic  acid,  boric  acid,  or  calcium  bisulphite. 

m.   Products. 

The  various  designations  that  have  been  given  to  malt  liquors  do  not 
necessarily  imply  distinctive  differences  in  the  character  of  the  product. 
They  represent  largely  the  different  usages  of  different  countries  and  local- 
ities. Thus,  in  England  Ale  was  at  one  time  brewed  without  hops,  but  the 
term  now  is  applied  to  a  beer  brewed  by  the  surface  fermentation  process, 
which  is  practically  the  only  method  used  in  England.  Porter  has  now 
come  to  mean  a  dark  malt  liquor,  made  partly  from  brown  or  black  malt,  the 
caramel  in  which  gives  it  the  sweetness  and  syrupy  appearance,  and  con- 
taining four  or  five  per  cent,  of  alcohol.  Stout  is  a  stronger  porter,  with 
larger  amount  of  dissolved  solids,  and  containing  six  or  seven  per  cent,  of 
alcohol. 

Lager-beer  is  beer  as  brewed  in  Germany  by  the  bottom  fermentation 
process,  which  process  is,  moreover,  retarded,  so  that  the  beer  has  better 
keeping  qualities.  It  also  has  a  larger  amount  of  hops  used  in  its  produc- 
tion. It  is  brewed  in  winter  for  storage  and  use  in  summer.  Schenk-beer 
is  also  a  bottom  fermentation  beer,  but  is  designed  for  use  as  soon  as  finished, 
and  the  process  is  somewhat  quicker  than  with  lager-beer,  and  a  smaller 


ANALYTICAL   TESTS   AND   METHODS. 


197 


amount  of  hops  is  used.  Bock-beer  is  a  stronger  lager-beer,  made  with 
one-third  more  malt,  and  brewed  specially  in  the  spring  of  the  year.  Weiss- 
beer,  as  before  stated,  is  made  chiefly  from  malted  wheat,  and  is  yet  in  the 
after- fermentation.  Most  other  names  are  from  localities,  and  represent  the 
characteristic  products  of  those  places. 

The  composition  of  various  English  and  German  beers  is  given  in  the 
accompanying  table  on  the  authority  of  Professor  Charles  Graham.-  (Allen, 
Commercial  Organic  Analysis,  2d  ed.,  vol  ii.  p.  92.) 


^ 

i 

o> 

11 

bo 
p 

•E 

1 

d 

od 

G| 

o 

|| 

1 

X 

II 

8S 

i 

'^2 

o 

£3 

1 

O 

*H 

o> 

3  G 

y 

3 

& 

u  3 

*? 

.2  °* 

fi 

5* 

•M 

1 

o 

*g 

1s 

Burton  pale  ale    .  . 

1.75 

2.48 

0.21 

0.55 

5.13 

0.02 

0.14 

5.37 

1:1.05 

Burton  bitter  ale  .  . 

1.62 

2.60 

0.16 

0.87 

5.42 

0.01 

0.17 

5.44 

1:100 

Mild  X  

1  87 

1.88 

0.20 

1.30 

5.39 

0.04 

0.14 

4.60 

1:0.85 

XXX 

2  88 

204 

0  30 

1.48 

680 

0.02 

0.10 

6.50 

1  :  0  96 

Scotch  export,  bitter 
Dublin  stout,  XX    . 

1.62 
3.45 

2^50 
3.07 

0^30 
0.26 

0.70 
1.76 

5.21 
8.71 

0.16 
0.01 

0.09 
0.17 

5.00 
5.50 

1  :  0.96 
1  :  0.63 

Dublin  stout,  XXX  .      . 

535 

2.09 

0.43 

1.40 

9.52 

0.04 

0.25 

6.78 

1:0.71 

Vienna  lager     .... 

1.64 

2.74 

0.36 

1.12 

590 

0.02 

0.13 

469 

1:0.78 

Pilsen  lager 

069 

2*65 

059 

4.22 

0.02 

0.09 

3.29 

1:080 

Munich  lager   

l'.57 

315 

0^40 

1.82 

7.08 

0.01 

0.14 

4.75 

1  :  0.67 

The  composition  of  various  American  beers  and  ales  as  analyzed  by 
C.  A.  Crampton,  of  the  United  States  Department  of  Agriculture,  is  also 
given.* 


» 

a 

o 

I 

o> 

H 

"S 

a 

CO  tj 

1 

h 

1 

j 

!.§ 
Ii 

* 

0 

| 

r 

r 

co  bo 

Milwaukee  lager,  bottled    .... 

1.10 

1.57 

0.51 

0.057 

0.196 

0.065 

4.18 

4.28 

1.0100 

Milwaukee  export  beer,  bottled  . 

1.06 

2.63 

0.40 

0.057 

0.309 

0.056 

5.40 

4.42 

1.0140 

Milwaukee  "  Bohemian  "  beer  .  . 

1.82 

3.04 

0.406 

0.071 

0.224 

0.057 

5.88 

4.16 

1.0183 

Milwaukee  "  Bavarian"  beer  .  . 

1.75 

2.87 

0.556 

0.074 

0.346 

0.077 

6.26 

5.06 

1.0187 

St.  Louis  export  beer     

2.14 

2.51 

0.463 

0.067 

0.312 

0.074 

6.15 

440 

1.0178 

St.  Louis  pale  lager,  bottled  .  .  . 

2.17 

2.75 

0.463 

0.067 

0.312 

0.064 

4.64 

4.28 

1.0178 

St.  Louis  "  Erlanger"  beer,  bottled 

2.51 

2.58 

0.675 

0.046 

0.183 

0.093 

6.82 

4.68 

1.0203 

Philadelphia  lager,  bottled     .  .  . 

1.46 

2.30 

0.538 

0.086 

0.241 

0.078 

5.22 

4.29 

1.0147 

Philadelphia  "  Budweiss,"  bottled 

2.14 

2.57 

0.531 

0.046 

0.265 

0.095 

5.94 

4.52 

1.0181 

Philadelphia  ale,  bottled   .... 

0.59 

0.90 

0.531 

0.232 

0.401 

0.085 

3.46 

6.24 

1.0059 

Reading  ale,  bottled  

0.93 

1.99 

0.731 

0.382 

0.472 

0.077 

5.55 

6.92 

1.0125 

Reading  porter,  bottled 

2.67 

2.88 

0.763 

0.166 

0.412 

0100 

8.19 

4.89 

1.0269 

IV.   Analytical  Tests  and  Methods. 

1.  FOR  MALT. — The  brewing  value  of  a  sample  of  malt  is  dependent 
upon  three  factors, — namely,  the  proportion  of  soluble  or  extractive  matter 
it  will  yield  to  water ;  the  character  of  this  extractive  matter ;  and  the  dias- 
tatic  activity.  The  extractive  matter  in  malt  is  usually  determined  by  a 
miniature  mashing  processs.  This  is  carried  out  as  follows  :  f  The  malt  is 
first  crushed  uniformly  fine;  fifty  grammes  are  then  weighed  out  as  rapidly 
as  possible  (on  account  of  its  hygroscopic  character),  and  placed  in  a  weighed 

*  United  States  Department  of  Agriculture.  Bulletin  No.  13,  Part  iii.  p.  282. 
t  Allen,  vol.  ii.  p.  26& 


198  FERMENTATION   INDUSTRIES. 

beaker  with  two  hundred  and  fifty  centimetres  of  distilled  water  at  50°  to 
52°  C.  After  a  short  digestion  at  this  temperature,  the  heat  is  gradually 
raised  to  59°  or  60°  C.,  and  this  temperature  maintained  until  a  drop  taken 
from  the  liquid  cease  to  give  a  blue  color  with  iodine  solution  and  nearly 
ceases  to  give  a  brown.  The  heat  is  then  increased  to  about  70°  C.  in  order 
to  complete  the  saccharification,  when  the  water  in  the  bath  surrounding  the 
beaker  is  boiled  for  five  minutes.  The  beaker  is  then  cooled  and  the  con- 
tents filtered.  The  insoluble  matter  is  washed  with  cold  water,  and  the 
filtrate  is  made  up  exactly  to  four  hundred  cubic  centimetres.  The  density 
of  the  clear  wort  is  next  taken  at  15.5°  C.  (60°  F.)  by  a  specific  gravity 
bottle.  For  most  purposes,  it  is  sufficiently  accurate  to  make  up  the  unfil- 
tered  wort 'to  four  hundred  and  fifteen  cubic  centimetres,  filter  a  portion 
through  a  dry  filter  and  take  the  density.  The  draff  is  here  assumed  to 
measure  fifteen  cubic  centimetres,  and  the  tedious  washing  is  dispensed  with. 
The  excess  of  density  over  that  of  water  (taken  at  1000)  multiplied  by 
2.078  will  give  the  percentage  of  dry  extract  yielded  by  the  malt.  This 
method  is  based  on  the  fact  that  each  gramme  of  malt  extract  per  hundred 
cubic  centimetres  of  infusion  has  been  shown  by  experiment  to  raise  the 
density  of  the  liquor  by  3.85  degrees  (water  =  1000).  The  figure  2.078 
is  then  the  fraction  -g-.^-g-.  Instead  of  ascertaining  the  gravity  of  the  infu- 
sion, the  proportion  of  solid  matter  may  be  determined  by  evaporating  a 
known  measure  of  the  wort  to  dry  ness  in  a  flat-bottomed  dish  so  that  the 
residue  may  form  a  thin  film.  This  is  dried  at  105°  C.  and  weighed. 
Other  methods  are  those  of  Metz,*  with  the  use  of  Schultze's  tables,  and  of 
Metz  as  improved  by  Weiss. 

The  determination  of  diastatic  power  in  a  sample  of  malt  is  also  of  im- 
portance in  valuing  it,  even  if  the  full  diastatic  power  is  not  likely  to  be 
called  out  in  the  brewing  process,  where  it  is  usually  in  excess  of  the  need  for 
the  production  of  a  beer- wort.  The  older  process  of  Lintnerf  depended  upon 
determining  by  the  aid  of  Fehling's  solution  the  amount  of  maltose  pro- 
duced by  the  action  of  a  cold  infusion  of  the  malt  upon  a  measured  starch 
solution.  This,  however,  supposes  that  the  action  of  diastase  upon  starch 
in  the  cold  is  always  uniform  and  produces  the  same  relative  amount  of 
maltose,  which  is  now  regarded  as  a  matter  of  some  uncertainty.  The 
method  proposed  by  Dunstan  (Allen,  2d  ed.,  vol.  ii.  p.  278)  simply  notes 
the  end  of  the  transformation  of  the  starch  by  the  absence  of  color  with 
iodine  solution.  For  it  five  grammes  of  very  finely-powdered  malt  are 
digested  and  agitated  for  one  hour  with  fifty  cubic  centimetres  of  cold  water. 
The  liquid  is  then  strained  off  and  the  residue  again  digested  for  an  hour  with 
fifty  cubic  centimetres  of  water,  and  the  liquids  are  then  mixed  and  made  up 
to  one  hundred  cubic  centimetres.  Five-tenths  gramme  of  starch  (dried  at 
100°  C.  before  weighing)  is  gelatinized  by  boiling  with  water,  and  the  cold 
liquid  diluted  to  one  hundred  cubic  centimetres.  The  solution  of  malt  extract 
is  then  added  to  twenty  cubic  centimetres  of  this  mucilage  by  instalments 
of  one  cubic  centimetre,  at  intervals  of  half  an  hour,  until  it  ceases  to  give 
any  color,  when  a  small  quantity  is  tested  with  a  dilute  solution  of  iodine. 
If  less  than  one  cubic  centimetre  of  the  solution  produces  this  effect,  more  of 
the  mucilage  should  be  added  and  the  operation  continued. 

To  determine  the  soluble  proteids  of  malt  assumed   to  represent  the 

*  Stohmann  and  Kerl,  Technische  Chemie,  4th  ed.,  pp.  1345-1351. 
i  Lintner,  Die  Bierbrauerei,  p.  530. 


ANALYTICAL   TESTS   AND   METHODS.  199 

diastase  C.   Graham  proposes  to  use  the  Wanklyn  albuminoid-ammonia 
process. 

2.  FOR  BEER- WORTS. — The  determination  of  the  specific  gravity  of  the 
wort  is  of  importance,  as  from  this  may  be  calculated  the  total  solid  matter 
in  the  wort.     If  from  the  specific  gravity  of  the  wort  we  take  1000,  and 
divide  the  difference  by  3.85,  we  get  the  number  of  grammes  of  solid  extract 
contained  in  one  hundred  cubic  centimetres  of  the  wort.     For-the  purpose 
of  the  brewer  special  forms  of  hydrometers  have  been  constructed,  the  read- 
ings of  which  are  immediately  available.     Thus,  Bates's  saccharometer  gives 
readings  of  pounds  per  barrel  (of  thirty-six  gallons), — that  is,  excess  of 
weight  in  pounds  of  a  barrel  of  wort  over  the  same  bulk  of  water.     These 
readings  can  then  be  converted  into  real  specific  gravity  figures  by  a  simple 
proportion,  using  the  weight  of  a  barrel  of  pure  water,  of  this  wort  with 
the  excess  of  weight  shown  by  the  saccharometer  reading  and  the  specific 
gravity  of  pure  water  as  terms.     The  Bates  saccharometer  readings  can  be 
converted  into  those  of  Balling  or  Brix  by  the  following  formula :    Ball- 

260  Bates         _,  .    ,     ,          ,  .  .  ...          ..      f 

mg=  — — f: — — .     I  he  method  ot  ascertaining  the  original  gravity  or 

beer- worts  which  have  undergone  fermentation  is  described  later.      (See 
following  page.) 

In  brewing,  the  relative  proportion  of  maltose  and  dextrine  in  the  wort 
is  of  great  importance  and  is  liable  to  considerable  variation,  being  dependent 
on  the  temperature  at  which  the  mashing  was  conducted,  the  length  of  time 
occupied  in  the  process,  and  the  diastatic  activity  of  the  malt  employed. 
The  composition  of  the  wort  largely  influences  the  subsequent  fermentation, 
as  a  wort  containing  little  dextrine  will  produce  of  beer  of  low  density  which 
will  clarify  readily,  but  be  "  thin"  and  apparently  much  weaker  than  beer  of 
the  same  original  gravity  but  higher  final  attenuation.  C.  Graham  esti- 
mates the  maltose  and  dextrine  in  beer- worts  from  the  cupric  oxide  reducing 
power  of  the  solution  before  and  after  inversion.  (For  details  of  his  pro- 
cedure, see  Allen,  vol.  ii.  p.  274.)  West  Knight  (Analyst,  vii.  p.  211)  has 
described  a  very  simple  and  rapid  method  of  approximately  determining 
the  dextrine  in  beer- worts.  Ten  cubic  centimetres  of  the  wort  is  treated  in 
a  small  weighed  beaker  with  fifty  cubic  centimetres  of  methylated  spirit  of 
.830  specific  gravity.  This  causes  the  precipitation  of  the  greater  part  of 
the  dextrine,  which  after  a  few  hours  collects  on  the  bottom  of  the  beaker  as  a 
gummy  mass,  from  which  the  alcoholic  liquid  can  be  poured  off.  The  deposit 
is  rinsed  with  a  little  more  spirit,  and  the  beaker  dried  in  the  water-oven 
and  weighed.  To  the  weight  obtained  an  addition  of  .045  gramme  is 
made  as  a  correction  for  the  dextrine  retained  in  solution  by  the  spirituous 
liquid. 

3.  FOR  BEER. — The  specific  gravity  of  the  beer  is  a  determination  that 
is  necessary  as  a  basis  of  calculation  for  the  other  determinations  as  to  its 
composition.     It  should  be  made  after  freeing  the  beer  from  carbon  dioxide 
as  fully  as  possible.     It  can  be  made  with  a  specific  gravity  flask,  but  is 
most  readily  and  accurately  carried  out  with  a  Westphal  specific  gravity 
balance  (see  Fig.  33),  which  for  this  purpose  is  provided  with  a  fourth  rider 
giving  the  fourth  place  of  decimals. 

The  amount  of  extract  is  frequently  determined  by  taking  a  definite  volume 
of  beer  of  which  the  specific  gravity  has  been  determined,  evaporating  it  to 
one-third  its  bulk,  and  then  adding  water  sufficient  to  restore  it  to  original 
bulk.  The  specific  gravity  of  this  liquid  is  then  determined  as  just  described. 


200  FERMENTATION   INDUSTRIES. 

The  percentage  of  extract  can  now  be  found  by  a  reference  to  Schulze's 
tables  for  determining  the  amount  of  extract  by  specific  gravity,  or  more 
simply  by  O'Sulli van's  method,  in  which  the  excess  of  this  specific  gravity 
over  1000  divided  by  3.86  gives  the  number  of  grammes  of  dry  extract  per 
one  hundred  cubic  centimetres  of  the  beer.  C.  Graham  considers  it  de- 
cidedly more  accurate  to  evaporate  five  cubic  centimetres  of  the  beer  on  a 
flat  watch-crystal  in  an  air-bath  at  a  temperature  of  from  70°  to  75°  C. 
The  complete  drying  of  the  film  requires  about  twenty-six  hours. 

The  percentage  of  alcohol  is  best  determined  by  distillation.  For  this 
purpose  one  hundred  cubic  centimetres  of  the  beer  are  taken,  a  few  drops 
of  caustic  soda  added  to  neutralize  the  free  acid,  and  the  liquid  brought  up 
to  about  one  hundred  and  fifty  cubic  centimetres.  It  is  then  distilled  with 
the  aid  of  a  Liebig  condenser  into  a  graduated  flask  until  nearly  one  hun- 
dred cubic  centimetres  have  come  over.  The  distillate  is  now  thoroughly 
mixed,  cooled  to  15°  C.,  and  then  brought  exactly  to  the  100-cubic-centi- 
metre  mark  and  again  mixed.  Its  specific  gravity  is  now  taken,  and  from 
a  set  of  alcohol  tables  (see  Hehner's  tables,  Appendix,  p.  522)  the  percentage 
of  alcohol  by  weight  of  the  distillate  found.  Then  as  the  specific  gravity  of 
the  original  sample  is  to  the  specific  gravity  of  the  distillate  so  is  the  weight 
per  cent,  in  the  distillate  to  the  weight  per  cent,  in  the  original  sample.  In- 
directly the  alcohol  percentage  can  be  determined,  although  not  with  the 
same  accuracy,  by  the  aid  of  the  data  gotten  in  the  determination  of  extract 
already  narrated.  For  if  the  specific  gravity  of  the  original  sample  be 
divided  by  the  specific  gravity  of  the  de-alcoholized  solution  we  get  the 
specific  gravity  of  the  alcohol  driven  off,  from  which -figure  the  percentage 
by  weight  of  alcohol  can  be  gotten  in  the  tables.  When  both  the  alcohol 
and  the  extract  percentage  of  a  beer  are  known,  by  Balling's  method  the 
percentage  of  extract  in  the  original  wort  can  be  calculated,  and  then  with 
the  aid  of  this  and  the  percentage  of  extract  in  the  beer  the  "  attenuation" 
or  diminution  in  the  gravity  of  the  original  wort  due  to  fermentation  and 
alcohol  production  can  be  determined.  As  the  weight  of  alcohol  produced 
is  approximately  fifty  per  cent,  of  the  saccharine  matter  destroyed  by  the 
fermentation,  we  have  the  formula  2a  -f-  e  —  w,  in  which  a  is  the  alcohol 
percentage,  e  the  extract  percentage  of  the  beer,  and  w  the  percentage 
strength  of  the  original  wort.  Then  using  this  figure  just  obtained  w  :  100 
: :  2a  :  x,  in  which  x  will  represent  the  degree  of  attenuation.  More  accu- 
rately, the  actual  degree  of  fermentation  (  Wirklicher  Vergdhrungsgrad)  is 
gotten  by  the  proportion  p  :p  —  n  : :  100  :  i/,  in  which  p  is  the  extract  in  the 
original  wort,  n  the  extract  in  the  beer,  and  vf  the  actual  fermentation  de- 
gree ;  (p  —  n)  is  termed  the  "  real  attenuation."  It  is  obvious  from  the  two 
proportions  given  that  in  practice  2a  is  often  taken  as  equivalent  to  ( p  —  n). 
This  is  not  strictly  correct.  It  is  found  in  the  fermentation  of  beer-worts 
that  100  parts  of  extract  yield  48.391  parts  of  alcohol,  so  that  what  is 
termed  an  "  alcohol  factor"  is  necessary  to  convert  one  into  the  other.  In 
England  a  different  procedure  is  followed.  A  definite  volume  of  beer  is 
taken  and  one-half  distilled  off4.  This  distillate  is  brought  up  with  water 
at  60°  F.  to  the  original  volume  and  its  specific  gravity  taken.  The  differ- 
ence between  1000  and  the  observed  gravity  is  called  the  "  spirit  indication" 
of  the  beer.  With  this  can  be  found,  in  a  table  prepared  for  the  Inland 
Revenue  Office,  the  "  degrees  of  gravity  lost"  by  the  attenuation  of  the 
wort.  Then  the  liquid  left  in  the  retort  after  the  distillation  is  diluted  with 
water  and  brought  up  to  the  original  volume,  when  its  specific  gravity  is 


RAW   MATERIALS.  201 

carefully  taken.  This  is  called  the  "  extract  gravity,"  and  this  added  to 
the  degrees  of  gravity  lost  gives  the  "  original  gravity  of  the  wort." 

The  acidity  of  beer  is  partly  due  to  lactic  and  succinic  acids,  which  are 
fixed  acids,  and  partly  to  acetic  acid,  which  is  volatile.  The  fixed  acids 
are  usually  determined  jointly  in  terms  of  lactic  acid  by  dissolving  the  dry 
extract  of  the  beer  in  water  and  titrating  the  solution  with  decinormal 
alkali  solution.  Baryta- water  is  preferred  by  many  chemists,~as~the  sul- 
phate of  baryta  which  forms  carries  down  much  of  the  coloring  and  allows 
the  end  reaction  to  be  better  seen.  The  volatile  acid  of  beer  is  chiefly  acetic 
acid,  which  is  usually  determined  by  subtracting  the  measure  of  alkali 
required  to  neutralize  the  extract  from  that  required  by  the  original  beer 
(after  getting  rid  of  the  carbonic  acid  by  shaking  thoroughly). 

The  chief  adulterations  of  beer  are  from  the  use  of  salicylic  acid  as  a 
preservative  and  the  addition  of  various  bitter  principles  as  substitutes  for 
hop-bitters.  The  salicylic  acid  may  be  searched  for  by  concentrating  the 
beer  to  one-half  at  a  gentle  heat  and  shaking  the  cooled  liquid  with  ether, 
or  a  mixture  of  ethylic  ether  and  petroleum-ether.  The  ethereal  layer  is 
then  separated,  evaporated  to  dryness,  and  the  residue  dissolved  in  warm 
water.  On  adding  ferric  chloride,  a  violet  coloration  is  produced  if  salicylic 
acid  be  present.  Other  chemists  recommend  dialyzing,  when  the  salicylic 
acid  will  readily  dialyze  into  the  pure  water  and  can  then  be  tested.  For 
the  detection  of  the  bitter  principles  used  as  substitutes  for  hops  elaborate 
schemes  have  been  proposed  by  Enders  (given  in  Allen,  vol.  ii.  p.  97)  and 
Dragendorff  (Gerichtliche-Chemische  Ausmittelung  der  Gifte). 

0.  THE  MANUFACTURE  OF  WINE. 
I.   Raw  Materials. 

1.  THE  GRAPE. — While  the  name  wine  is  often  used  to  include  the 
products  of  the  spontaneous  alcoholic  fermentation  of  any  sweet  fruit  or 
berry,  it  is  usually  limited  to  the  product  of  the  fermentation  of  the  grape, 
which  alone  is  cultivated  on  an  extensive  scale  throughout  the  civilized 
world  purely  for  the  manufacture  of  wine. 

The  cultivation  of  the  grape-vine  and  the  production  of  wine  therefrom 
dates  back  to  the  earliest  historic  times.  Beginning  in  the  East  and  the 
Mediterranean  lands,  it  extended  northward  and  westward  until  at  present 
France  is  the  chief  wine-producing  country,  while  Germany,  Austria,  Spain, 
and  Portugal  have  all  established  flourishing  wine  industries  indigenous  to 
their  soil.  In  this  country,  the  wine  industry  is  mainly  established  in  the 
States  of  Ohio,  New  York,  Virginia,  and  California. 

The  varieties  of  the  vine  (estimated  to  number  almost  two  thousand) 
hitherto  cultivated  in  Europe  are  all  said  to  be  derived  from  the  single 
species,  Vitis  vinifera.  In  this  country  four  or  five  wild  species  have  yielded 
varieties  which  when  cultivated  have  proven  adapted  to  wine  production. 
Thus  Vitis  riparia,  or  "  frost-grape,"  has  yielded  as  cultivated  varieties  the 
Taylor  and  the  Clinton  grapes ;  the  Vitis  cestivalis,  or  "  summer-grape,"  has 
yielded  as  varieties  Norton's  Virginia,  Cythiana,  and  Herbemont ;  the  Vitis 
Labrusca,  or  "  Northern  fox-grape,"  has  yielded  as  varieties  the  Catawba, 
Isabella,  Concord,  and  Delaware  grapes ;  the  Vitis  vulpina  or  rotundifolia, 
or  "  Southern  muscadine,"  has  yielded  as  varieties  the  black,  red,  and  white 
Scuppernong.  Numerous  varieties  of  the  European  vine,  the  Vitis  vim/era, 


202 


FERMENTATION   INDUSTRIES. 


have  also  been  cultivated  successfully  in  California,  among  which  may  be 
mentioned  the  Mission,  Riesling,  Traminer,  Rulander,  Gutedel,  and  Zin- 
fandel. 

The  grapes  owe  their  wine-producing  value  in  the  first  place  to  the 
grape  (or  invert)  sugar  which  they  contain,  and  in  the  second  place  to  the 
free  acids,  which  in  the  later  ripening  of  the  wine  are  to  develop  the  fra- 
grant ethers,  and  to  the  albuminoids,  which  exert  a  great  influence  on  the 
fermentation.  The  composition  of  the  grape  varies  of  course  in  different 
localities  and  even  from  year  to  year  in  the  same  locality,  but  its  mean  com- 
position is  thus  stated  by  Konig :  Grape-sugar,  14.36  per  cent. ;  free  acid 
(tartaric),  .79  per  cent. ;  nitrogenous  material,  .59  per  cent. ;  non-nitrogen- 
ous extract,  1.96  per  cent.;  skins  and  kernel,  3.60  per  cent.;  ash,  .50 -pel- 
cent.  ;  and  water,  78.17  per  cent. 

The  grapes  are  taken  for  wine-making  only  when  they  are  fully  ripe, 
and  in  many  localities  it  is  even  customary  to  wait  until  the  grape  shows  a 
slight  appearance  of  over-ripeness  or  evidence  of  wilting,  so  that  the  maxi- 
mum of  sweetness  may  be  attained.  In  some  cases  the  grapes  are  plucked 
from  the  stems,  either  by  hand  or  by  the  aid  of  three-pronged  forks,  while 
in  other  cases  the  stems  are  left  when  they  are  crushed  in  order  that  the 
tannin  so  obtained  may  aid  in  the  clearing  of  the  fermenting  juice.  This 
juice  is  known  as  "  must,"  and  the  pressed  pulp  and  skins  as  the  "  marc." 

2.  THE  MUST. — This  may  properly  be  considered  as  still  a  raw  mate- 
rial, as  its  expression  from  the  grapes  is  purely  a  mechanical  process.  This 
is  now  generally  effected  by  power-presses  of  various  forms,  although  at 
one  time  largely  effected  by  trampling  the  grapes  under  feet.  (This  method 
is  still  followed  in  the  Oporto  and  the  Madeira  wine  districts.)  The  first 
portion  of  must  that  runs  from  the  presses  is  often  collected  separately,  as 
it  is  the  juice  of  the  ripest  and  sweetest  grapes ;  that  which  comes  later  is 
richer  in  acid  and  in  tannin,  as  it  comes  partly  from  unripe  grapes  and 
partly  from  the  stems  and  skins.  The  amount  of  must  that  is  obtained 
usually  ranges  from  sixty  to  seventy  parts  in  the  one  hundred  of  grapes. 

The  composition  of  this  must  is  of  the  greatest  importance,  as  upon  it 
depends  the  character  of  the  wine  that  will  be  produced,  whether  it  shall 
ferment  normally  throughout  and  develop  the  perfect  flavor  and  aroma  de- 
sired, or  whether  it  shall  be  thin  and  sour  and  show  tendencies  towards 
alteration  or  "  disease."  The  proportions  of  its  constituents,  especially  the 
grape-sugar,  may  vary  within  quite  wide  limits  from  year  to  year,  and  in 
grapes  grown  in  the  same  year  under  different  conditions  of  soil,  exposure,  etc. 

Thus,  two  different  musts  of  1868  are  given  and  two  musts  of  the  same 
variety  of  grape  in  two  succeeding  years,  the  first  of  which  was  a  favorable 
year  and  the  second  an  unfavorable  year.  The  analyses  are  all  by  Neubauer, 


Sugar. 

Free 
acid. 

Albumi- 
noids. 

Ash. 

Non-nitro- 
genous 
extract. 

Water. 

Neroberger  Riesling,  1868  .... 

1806 

042 

0.22 

0.47 

4.11 

76.72 

Steinberger  Auslese,  1868  

24.24 

0.43 

0.18 

0.45 

3.92 

70.78 

Hattenheimer,  1868,  (good  year)  .    .    . 

23.56 

0.46 

"0.19 

0.44 

5.43 

69.92 

Hattenheimer,  1869,  (bad  year)     .    .    . 

16.67 

0.79 

0.33 

0.24 

5.17 

76.80 

The  percentage  of  grape-sugar  in  the  must  sinks  at  times  to  twelve  per 
cent.,  and  may  rise  as  high  as  twenty-six  to  thirty  per  cent.     The  ratio 


PROCESSES   OF   MANUFACTURE.  203 

between  acid  and  sugar,  according  to  Fresenius,  ranges  from  1  : 29  for  good 
varieties  of  grapes  in  good  years  to  1  : 16  for  inferior  varieties  in  medium 
years.  If  the  ratio  falls  as  low  as  1  : 10,  the  grapes  are  unripe  and  taste 
acid.  This  ratio  of  acid  to  sugar  is  now  generally  taken  as  the  criterion  for 
the  quality  of  the  must  in  any  year  or  special  locality. 

In  bad  seasons  the  free  acid  is  more  generally  malic  than  tartaric,  which 
is  the  normal  constituent. 

n.   Processes  of  Manufacture. 

1.  FERMENTATION. — The  fermentation  of  the  must  is  a  spontaneous 
one  following  exposure  to  the  air,  and  due  to  the  spores  which  drop  upon 
the  surface  of  the  must  as  exposed  in  the  fermenting-tubs.  It  may  be  a 
surface  fermentation,  taking  place  at  temperatures  of  15°  to  20°  C.,  as  is 
the  practice  in  Italy,  Spain,  and  the  south  of  France,  or  a  bottom  fermen- 
tation, taking  place  in  cooler  cellars  at  5°  to  12°  C.,  as  is  the  practice  in 
Germany  and  with  the  finer  French  wines.  The  first  method  produces  a 
fiery  wine  rich  in  alcohol,  but  without  bouquet  or  aroma  ;  the  second  method, 
lighter  wines  with  delicate  bouquet,  due  to  the  formation  of  wine  ethers. 
In  either  case  the  fermentation  can  be  divided,  as  was  the  case  with  malt 
liquors,  into  three  stages :  the  first,  or  main  fermentation,  which,  according 
as  the  surface  or  the  bottom  fermentation  method  is  followed,  lasts  from  three 
to  eight  days,  or  from  two  to  four  weeks ;  the  second,  or  still  fermentation, 
which  lasts  until  the  following  spring ;  and  the  third,  the  storage  fermen- 
tation, which  lasts  for  several  years,  until  by  the  gradual  development  of  its 
bouquet  it  becomes  perfectly  ripe. 

In  the  case  of  red  wines,  the  main  fermentation  is  allowed  to  take 
place  with  the  marc  added  to  the  must,  so  that  as  the  alcohol  is  developed 
it  may  dissolve  out  the  coloring  matter  (oenocyanin)  of  the  skins  as  well  as 
some  of  the  tannin,  which  latter  is  of  benefit  in  effecting  a  more  rapid 
separation  of  the  protein  materials.  To  prevent  this  pulpy  mass  from 
rising  to  the  surface  and  starting  a  souring  of  the  wine,  perforated  covers 
are  often  used  in  this  case  to  hold  it  down.  In  the  main  fermentation,  the 
casks  are  usually  freely  exposed  to  the  air  Many  wine  experts  recommend 
in  addition  the  aeration  of  the  fermenting  must  or  a  whipping  of  the 
liquid,  so  as  to  induce  a  fuller  and  more  vigorous  fermentation  On  the  other 
hand,  other  authorities  consider  that  this  excessive  exposure  to  air  injures 
the  quality  and  aroma  of  the  wine,  and  recommend  only  a  partial  exposure 
to  the  air  after  the  main  fermentation  has  begun.  As  the  main  fermenta- 
tion comes  to  an  end,  the  yeast  (with  more  or  less  tartar,  gummy  matter, 
and  albuminoids)  settles  to  the  bottom,  the  liquid  clears  and  is  ready  to  be 
racked  off  into  casks,  under  the  name  of  young  wine  (Jungwein),  to  undergo 
the  after-  or  still  fermentation.  If  the  racking  off  does  not  take  place 
promptly  with  the  ending  of  the  more  energetic  main  fermentation,  the 
young  wine,  of  which  a  considerable  surface  is  exposed  to  the  air,  is  very 
apt  to  start  into  the  acetic  fermentation.  The  casks  into  which  it  is  now 
put  are  kept  quite  full  in  order  to  prevent  this  undesirable  change,  slight 
additions  being  made  every  few  days  if  necessary,  and  the  bungs  are  set 
loosely  in  place.  During  this  after-fermentation  there  deposits  upon  the 
inner  walls  of  the  cask  argoh,  or  impure  acid  potassium  tartrate  (Wein- 
stein),  with  some  yeast  and  albuminoid  matter.  This  fermentation  lasts 
from  three  to  six  months,  and- then  the  wine  is  racked  off  again  into  smaller 


204  FERMENTATION   INDUSTRIES. 

casks  to  undergo  the  final  ripening,  in  which  the  bouquet  of  the  wine  is 
especially  developed  by  the  formation  of  ethers,  while  it  clears  more  thor- 
oughly from  the  remaining  particles  of  yeast,  etc.  The  duration  of  this 
ripening  may  be  two,  four,  or  with  rich  wines  even  eight  years  or  more, 
when  it  is  considered  "  bottle-ripe."  During  this  ripening  fungous  vegeta- 
tion is  very  apt  to  start,  and  must  be  arrested  in  order  to  prevent  the 
spoiling  of  the  wine. 

2.  DISEASES  OF  WINES  AND  METHODS  OF  TREATING  AND  IM- 
PROVING THEM. — The  souring  of  wine,  due  to  the  beginning  of  the  acetic 
fermentation,  is  one  of  the  commonest  of  these  so-called  diseases,  especially 
with  light  wines,  poor  in  alcohol  and  tannic  acid,  and  hence  commoner 
with  white  than  with  red  wines.  It  arises  from  too  free  an  exposure  to 
the  air  and  too  high  a  temperature  during  fermentation.  If  just  begun,  it 
can  be  cured  by  the  addition  of  a  small  quantity  of  potashes,  which  form 
potassium  acetate,  or  by  starting  the  alcoholic  fermentation  afresh  by  add- 
ing a  new  quantity  of  sugar.  If  the  souring  is  very  pronounced  it  cannot 
be  cured,  and  the  wine  is  made  into  wine-vinegar. 

The  gumminess  or  ropiness  of  wine  frequently  arises  from  a  premature 
filling  into  bottles,  and  is  due  to  the  beginning  of  the  mucous  fermentation 
of  sugar.  It  takes  place  in  wines  poor  in  tannic  acid,  and  hence  more 
readily  with  white  than  with  red  wines.  It  can  be  cured  by  addition  of 
tannic  acid,  treatment  with  sulphurous  oxide,  or  starting  a  new  fermenta- 
tion by  addition  of  grape-sugar. 

The  development  of  a  stale  or  flat  taste  in  the  wine  is  due,  according  to 
Pasteur,  to  the  growth  of  a  thread-like  ferment.  The  wine  becomes  cloudy, 
diminishes  in  alcohol  and  increases  in  acid  percentage,  it  darkens  in  color, 
and  often  has  a  disagreeable  odor.  The  wine  is  racked  off  and  put  into  a 
cask  which  has  been  filled  with  sulphurous  oxide  fumes,  which  destroy  the 
ferment. 

The  turning  bitter  of  red  wines  is  due  also,  according  to  Pasteur,  to  a 
plant-growth,  according  to  others  to  the  formation  of  a  bitter  aldehyde 
resin.  Neubauer  has  found  that  the  tannic  acid  and  the  coloring  matter 
both  decrease  in  percentage  in  this  disease.  It  can  be  cured  completely  by 
heating  the  wine  to  60°  to  64°  C.,  or  by  starting  the  fermentation  anew  by 
adding  fresh  quantities  of  grape-sugar. 

The  mouldiness  of  wine  is  due  to  the  development  of  a  fungoid  growth 
in  the  form  of  a  white  film  on  the  surface  of  wines  poor  in  alcohol,  and 
always  precedes  the  souring  of  the  wine.  It  is  to  be  obviated  by  treat- 
ment with  sulphur  dioxide  or  more  effectual  protection  of  the  young  wine 
from  the  air. 

Of  the  general  lines  of  treatment  adopted  to  prevent  the  development 
of  these  various  diseases,  we  notice  first  the  clarifying  with  isinglass 
(finings)  or  other  form  of  gelatine.  This  is  particularly  applied  to  the 
sweet  and  heavy  white  wines,  which  often  remain  turbid  and  have  to  be 
cleared  by  the  coagulating  of  the  albuminoid  which  is  added.  With  red 
wines  which  contain  tannic  acid,  casein  or  blood  albumen  is  used  instead 
of  gelatine.  Fine  clays  are  also  used,  especially  in  Spain,  for  this 
clarifying. 

The  most  important  process,  however,  which  is  applied  for  the  preser- 
vation and  protection  of  wine  against  diseases  is  that  known  as  "  Pasteur- 
izing." It  consists  in  heating  the  wine  either  in  casks  or  in  bottles  to  a 
temperature  of  60°  C.,  and  then  preserving  it  without  exposure  to  the  air. 


PROCESSES   OF   MANUFACTURE. 


205 


This  temperature  is  found  to  be  sufficient  to  kill  most  of  the  germs  which 
bring  about  the  diseases  before  mentioned.  A  form  of  cask  much  used  for 
this  "  Pasteurizing"  process  is  shown  in  Fig.  63. 


FIG.  63. 


The  use  of  salicylic  acid  for  preserving  wines  has  been  extensively  tried, 
but  its  use  here  is  open  to  the  same  objection  as  before  stated  in  speaking  of 
beer,  and  it  is  now  forbidden  in  most  countries. 

Of  the  methods  of  "  improving"  wines,  as  it  is  termed,  that  known  as 
"  plastering"  is  probably  most  largely  practised,  its  use  for  red  wines  ex- 
tending to  Spain,  Portugal,  Italy,  and  the  South  of  France.  It  consists  in 
adding  plaster  of  Paris  (burnt  gypsum)  either  to  the  unpressed  grapes  or  to 
the  must.  The  plaster  takes  up  water  and  so  increases  the  alcoholic  strength 
of  the  fermenting  must,  which  in  turn  allows  of  a  greater  extraction  of  the 
coloring  matter  from  the  skins.  At  the  same  time  the  wine  is  given  bet- 
ter keeping  qualities  as  well  as  deeper  color.  However,  the  sulphate  of 
lime  changes  the  soluble  potash  salts  of  the  wine  into  insoluble  tartrate  of 
lime  and  soluble  acid  sulphate  of  potash,  which  latter  remains  dissolved 
along  with  some  of  the  gypsum,  and  undoubtedly  has  an  injurious  effect 
upon  the  consumers  of  the  wine.  The  process  has  hence  had  to  be  con- 
trolled by  law,  and  in  France  the  sale  of  wine  containing  over  .2  per  cent, 
of  potassium  sulphate  is  prohibited.  The  ash  of  pure  wine  does  not  exceed 
.3  per  cent.,  but  in  the  samples  of  sherry  usually  met  with  it  reaches  .5  per 
cent.,  and  is  almost  entirely  composed  of  sulphates. 

Hugonneng  recommends  adding  dicalcium  phosphate  instead  of  gypsum. 
This  process,  called  "  phosphotage,"  is  said  to  have  all  the  good  effects  ob- 
tainable from  plastering  without  increasing,  as  the  latter  does,  the  percentage 
of  sulphuric  acid  and  decreasing  that  of  phosphoric  acid. 

Chaptalization  consists  in  neutralizing  the  excess  of  acidity  in  the  must 
by  the  addition  of  marble-dust,  and  increasing  the  saccharine  content  by 


206  FERMENTATION   INDUSTRIES. 

the  addition  of  a  certain  quantity  of  cane-sugar,  which  the  vintners  some- 
times replace  by  starch-sugar.  In  this  process  the  quantity  of  the  wine  is 
not  increased,  but  it  becomes  richer  in  alcohol,  poorer  in  acid,  and  the 
bouquet  is  not  injured.  It  is  much  used  in  Burgundy. 

Gallization,  as  proposed  by  Dr.  Gall,  has  for  its  object  the  bringing  of 
the  must  of  a  bad  year  up  to  the  standard  found  to  belong  to  a  good  must 
(he  takes  as  standard  24  per  cent,  of  sugar,  .6  per  cent,  of  acid,  and  75.4 
per  cent,  of  water)  by  correcting  the  ratio  of  acid  to  sugar.  This  he  does 
by  adding  sugar  and  water  in  sufficient  quantity,  and  tables  have  been  pre- 
pared to  indicate  the  quantity  needed  according  to  the  acid  ratio  shown  by 
analysis.  In  both  these  processes,  starch-sugar  ought  never  to  be  used  as 
a  cheaper  substitute  for  cane-sugar,  as  commercial  starch-sugar  will  always 
introduce  dextrine,  an  entirely  foreign  constituent,  into  the  must. 

Petiotization  is  a  process  which  takes  its  name  from  Petiot,  a  proprietor 
in  Burgundy,  and  is  carried  out  as  follows :  The  marc  from  which  the 
juice  has  been  separated  as  usual  by  pressure  is  mixed  with  a  solution  of 
sugar  and  water  and  the  mixture  again  fermented,  the  second  steeping  con- 
taining, like  the  first,  notable  quantities  of  bitartrate  of  potash,  tannic  acid, 
etc.,  which  are  far  from  being  exhausted  by  one  extraction.  The  process 
may  be  repeated  several  times,  the  different  infusions  being  mixed.  This 
process  is  very  largely  used  in  France,  and  is  said  to  produce  wines  rich  in 
alcohol,  of  as  good  bouquet  as  the  original  wine,  and  of  good  keeping  quali- 
ties. It  is  not  allowed  to  be  sold  there,  however,  as  natural  wine. 

Scheelization  consists  in  the  addition  of  glycerine  to  the  finished  wine  so 
as  to  improve  the  sweet  taste  without  injuring  its  keeping  qualities.  The 
limits  of  the  addition  of  glycerine  lie  between  one  and  three  litres  to  the 
hectolitre  of  wine.  If  the  wine  has  not  fully  fermented,  however,  and  if 
yeast-cells  are  present,  the  glycerine  may  yield  propionic  acid  by  decompo- 
sition. 

3.  MANUFACTURE  OF  EFFERVESCING  WINES  (Champagnes). — For  the 
manufacture  of  champagne  the  blue  sweet  grapes  are  preferred.  They  must 
be  pressed  promptly  after  picking  in  order  that  the  least  possible  amount  of 
color  be  taken  up  by  the  must.  The  first  pressing  only  is  used  for  the  cham- 
pagne, and  a  second  pressing  of  the  marc  yields  a  reddish  wine,  which  is  differ- 
ently utilized.  The  must  is  first  put  into  vats  that  impurities  may  settle  and 
then  filled  into  casks  for  the  main  fermentation,  which  is  retarded  as  much 
as  possible  by  being  carried  out  in  cool  cellars.  Cognac  is  also  added  to  the 
amount  of  about  one  per  cent.,  so  as  to  increase  the  alcohol  percentage  and 
thus  moderate  the  fermentation.  After  the  main  fermentation  is  finished  the 
wine  is  racked  off  into  other  casks  and  left  stopped  until  winter  (end  of 
December).  It  is  then  fined  (or  cleared)  with  isinglass  and  transferred  to 
other  casks,  and  this  operation  is  repeated  in  a  month's  time.  Towards  the 
beginning  of  April  it  is  ready  to  be  transferred  to  bottles.  The  wines  of 
different  growths  are  now  mixed  and  the  amount  of  sugar  in  the  wine  de- 
termined, when  a  calculated  .additional  quantity  is  added  in  the  form  of 
"  liqueur"  (a  mixture  of  alcohol  and  pure  cane-sugar).  The  bottles  which 
are  to  receive  the  champagne  must  be  specially  chosen  and  be  sufficiently 
strong  to  stand  the  pressure,  which  rises  later  to  four  to  five  atmospheres. 
They  must  also  have  sloping  sides,  so  that  the  sediment  may  not  adhere  to 
the  sides  in  the  after-process.  The  wine  after  being  corked  is  thoroughly 
secured  by  an  iron  fastening  called  an  agrafe,  and  the  bottles  are  arranged 
in  piles  in  a  horizontal  position  in  the  large  champagne-vaults,  where  they 


PROCESSES   OF   MANUFACTURE.  207 

remain  throughout  the  summer  months.  Previous  to  the  wine  being  pre- 
pared for  shipment,  the  bottles  are  placed  in  a  slanting  position,  neck  down- 
ward, in  frames,  and  the  incline  is  gradually  increased  day  by  day  until  the 
bottle  is  almost  perpendicular.  With  the  sediment  thus  on  the  cork  it  goes 
into  the  hands  of  a  workman  called  a  "  disgorger,"  who,  holding  the  bottle 
still  neck  downward,  proceeds  to  liberate  the  cork  by  slipping  off  the  agrafe, 
and  when  the  cork  is  three-fourth  parts  out  he  quickly  inverts  4he- bottle. 
The  cork  is  thus  forcibly  ejected  with  a  loud  report  by  the  froth,  which  car- 
ries with  it  the  greater  part  of  the  yeast  and  other  solid  matters,  what  re- 
mains of  these  being  got  rid  of  by  the  workman  working  his  finger 
round  the  neck  of  the  bottle,  whereby  they  are  detached  and  forced  out 
by  the  still  rising  froth.  The  wine  is  now  dosed  again  with  liqueur,  the 
bottles  filled  up,  wired,  and  the  neck  wrapped  with  foil  ready  for  ship- 
ment. 

4.  MANUFACTURE  OF  FORTIFIED,  MIXED,  AND  IMITATION  WINES. — 
All  the  sweet  heavy  wines,  like  sherry,  malaga,  and  port,  are  characterized 
by  a  high  alcohol  percentage,  ranging  from  sixteen  to  twenty  or  twenty  -two. 
This  they  cannot  acquire  through  fermentation  alone,  as  twelve  to  thirteen 
per  cent,  seems  to  be  the  limit  of  alcohol  developed  in  a  wine  by  direct  fer- 
mentation. They  have  the  additional  alcohol  added  to  them  directly  in 
order  to  give  them  keeping  qualities.  With  some  sweet  wines  the  alcohol 
is  added  to  the  must  before  the  fermentation  in  order  that  the  fermentation 
shall  be  arrested,  while  a  certain  amount  of  sugar  remains  in  the  wine 
unchanged.  The  quality  of  wines  is  often  improved  by  blending.  Light 
wines  with  too  little  alcohol  are  mixed  with  stronger  wines  with  the  forma- 
tion of  an  excellent  product  with  better  keeping  qualities,  which  can  then 
be  transported  to  long  distances  without  injury.  These  mixtures  can  best  be 
made  when  the  wines  are  new,  in  order  that  after  mixing  they  may  undergo 
an  insensible  fermentation  and  take  a  character  distinctive  of  the  new 
product. 

The  practice  of  adding  flavoring  substances  totally  foreign  to  the  con- 
stituents of  the  must  to  new  and  inferior  wines  in  order  that  they  may  take 
the  flavor  and  appearance  of  older  and  more  valuable  wine  has  also  become 
very  wide-spread.  Such  practices  are  of  course  illegal  in  all  countries  where 
laws  against  adulteration  are  enforced.  Thus,  elder  flowers,  orris-root,  iris, 
cloves,  oil  of  bitter  almonds,  and  numerous  perfumes,  such  as  oil  of  orange 
flowers,  of  neroli,  of  petit-grain,  and  of  violet,  are  used,  as  well  as  coloring 
infusions  like  rasp  berries  and  walnuts.  The  heavy  wines  are  the  ones  most 
generally  imitated.  Port  is  frequently  flavored  with  a  mixture  of  elderberry 
juice,  grape  juice,  brown  sugar,  and  crude  brandy.  Sherry  often  consists 
of  the  cheaper  Cape  wine  mixed  with  honey,  bitter  almonds,  and  brandy. 
In  Spain  and  Southern  France  a  wine  prepared  from  the  vine  known  as  the 
Teinturier  and  possessing  an  intense  bluish-red  color  is  extensively  used  for 
coloring  of  other  wines. 

In  recent  years,  because  of  the  deficiency  in  the  wine  crop  of  France 
due  to  the  ravages  of  the  Phylloxera,  the  production  of  wine  from  dried 
raisins  or  prunes  has  enormously  increased.  This  product,  known  as  "  vin 
de  raisin  sec,"  is  said  to  be  a  very  close  imitation  of  natural  French  wines. 
Spon  *  gives  the  following  as  the  components  of  such  a  raisin  wine : 

*  Spon's  Encyclopedia  of  Industrial  Arts,  vol.  ii.  p.  444. 


208 


FERMENTATION   INDUSTRIES. 


White  sugar 6  kilos. 

Raisins 5  kilos. 

Common  salt 125  grammes. 

Tartaric  acid 200  grammes. 


Common  brandy     ....    12  litres. 

River  water 95  litres. 

Gall-nuts  (bruised)    ...    20  grammes. 
Brewer's  yeast  (in  paste)  .  200  grammes. 


To  make  this  wine  of  a  red  color  it  is  necessary  only  to  add  to  the  above 
ingredients  two  hundred  and  fifty  to  three  hundred  grammes  of  dry  picked 
hollyhocks,  taking  care  to  keep  them  at  the  bottom  of  the  cask. 

The  reports  of  the  United  States  consular  agents  show  that  the  manu- 
facture of  this  raisin  wine  has  become  an  industry  of  large  proportions  in 
France  at  the  present  time.  A  significant  additional  indication  of  the  devel- 
opment of  this  artificial  wine  industry  and  of  the  similar  one  of  petiotiz- 
ing  in  France  is  found  in  the  statement  of  the  amounts  of  cane-sugar  used 
by  French  wine  manufacturers  in  recent  years.  In  1885  there  was  used  in 
France  for  the  manufacture  of  grape  wines  7,933,887  kilos,  of  cane-sugar; 
in  1886,  27,856,592  kilos.;  for  the  manufacture  of  fruit  wines  in  1885, 
24,142  kilos,  of  sugar ;  in  1886,  for  the  same  purpose,  145,555  kilos.  Most 
of  this  fruit  wine  forms  the  basis  of  factitious  champagne. 

m.  Products. 

The  normal  constituents  of  a  natural  wine  agree  of  course  with  those 
contained  in  the  must,  except  in  so  far  as  new  compounds  have  been  devel- 
oped by  the  fermentation  process  and  previously  existing  ones  have  been 
decomposed  or  made  to  separate  out. 

We  may  divide  the  constituents  of  wine  into  two  classes,  volatile  and 
fixed.  The  volatile  matters  are  as  follows  :  Water  (eighty  to  ninety  per 
cent.)  ;  alcohol  (five  to  fifteen  per  cent.) ;  glycerine  (two  to  eight  per  cent.) ; 
volatile  acids,  acetic,  oenanthic,  etc.,  constituting  one-fourth  to  one-third 
of  the  total  acidity ;  aldehyde,  compound  ethers,  together  with  other  fra- 
grant indefinite  constituents,  which  give  the  wine  its  flavor  and  bouquet. 
The  fixed  matters  are  glucose,  or  grape-sugar,  in  small  quantities  in  most 
wines ;  bitartrate  of  potash,  tartaric,  malic,  and  phosphoric  acid,  partly  free 
and  partly  combined  with  various  bases,  of  which  compounds  phosphate  of 
lime  is  the  most  abundant,  constituting  from  twenty  to  sixty  per  cent,  of  the 
weight  of  the  ash,  the  remainder  being  chiefly  carbonate  of  potash,  result- 
ing from  the  calcination  of  the  bitartrate,  with  a  little  sulphate  and  traces 
of  chlorides ;  coloring  matters ;  pectin  and  analogous  gummy  matters ;  tannin, 
one  to  two  per  cent,  in  red  wines  and  traces  only  existing  in  white  wines. 

No  very  simple  scheme  of  classification  is  possible,  as  the  methods  and 
products  of  most  countries  are  not  fixed  by  rule,  but  vary  widely  according 
to  the  season  and  market.  Still,  we  may  distinguish  between  the  red  and 
white,  and  the  sweet  and  the  diy,  wines ;  between  the  light  and  delicately- 
flavored  German  and  French  wines  and  the  more  fiery  but  coarser  Italian 
and  Swiss  wines ;  between  natural  wines  and  those  fortified  by  addition  of 
alcohol,  as  port,  sherry,  and  madeira ;  between  still  wines  and  effervescing 
or  champagne  wines. 

Most  of  these  terms  have  already  found  their  explanation  in  the  descrip- 
tion of  the  processes  of  manufacture.  We  may  add  that  a  sweet  wine  is  one 
in  which  a  notable  portion  of  the  original  grape-sugar  of  the  must  has 
escaped  fermentation,  or  to  which  an  addition  of  sugar  has  been  made  sub- 
sequent to  the  main  fermentation.  A  dry  wine,  on  the  contrary,  is  one  in 
which  the  sugar,  whether  originally  present  or  subsequently  added,  has 


PRODUCTS. 


209 


almost  all  undergone  change  in  the  processes  of  fermentation.  Champagnes 
are  wines  in  which  a  supplementary  fermentation  is  purposely  developed 
subsequent  to  the  bottling,  whereby  quantities  of  carbon  dioxide  gas  are 
developed  and  held  dissolved  under  pressure.  On  opening  the  bottles  and 
thus  relieving  the  pressure  a  brisk  effervescence  follows,  due  to  the  escape 
of  the  absorbed  gas.  Champagne-makers  distinguish  three  grades  of  effer- 
vescence. In  mousseux  the  pressure  in  the  bottle  amounts  to  from  four  to 
four  and  a  half  atmospheres ;  in  grand  m,ousseux  it  reaches  five  atmospheres ; 
and  less  than  four  atmospheres'  pressure  constitutes  cremant  (from  la  creme, 
"  cream"),  a  wine  which  throws  up  a  froth,  but  does  not  give  off  carbonic 
acid  violently.  Some  manufacturers  also  distinguish  a  grade  demi-mousseux. 
Of  natural  and  unfortified  foreign  wines  the  following  analyses  from 
Eisner  *  refer  to  German  wines  exclusively  : 


o 

o 

*J 

o 

«M 

g| 

f! 

ft 

fit 

f. 

Hi 

P 

00 

p 

QJ   0> 

Jp 

I1 

Rhine  wines,  Rudesheimer     .    .    . 

0.9960 

9.30 

1.97 

0.50 

0.20 

0.020 

"          "       Rauenthaler  .... 

0.9960 

925 

2  10 

0.54 

0.19 

0.023 

u          "       Johannisberger    .    . 

0.9958 

8.60 

2.20 

0.52 

019 

0.023 

"          "       Hochheimer  .... 

0.9935 

8.00 

1.50 

0.72 

0.16 

"          "       Niersteiner    .... 

0.9956 

7.54 

1.75 

0.62 

0.18 

6.012 

Moselle  wines,  Brauneberger  .   .    . 

.    . 

2.60 

. 

0.18 

0.041 

2.40 

0.15 

0.038 

2.40 

0.16 

0.039 

Hessian  wines>  Bodenheimer  .   .    . 

0.9930 

754 

1.25 

6.63 

0.14 

"          "        Laubenheimer   .    . 

0.9934 

6.83 

1.00 

0.60 

0.10 

. 

"          "        Liebfrauenmilch   . 

0.9940 

8.00 

1.96 

0.62 

0.20 

t 

Palatinate  wines,  Deidesheimer     '. 

0.9968 

9.60 

2.12 

0.50 

0.18 

... 

"       Oppenheimer    . 
"            "       Wachenheimer  . 

0.9935 
0.9954 

8.87 
8.65 

1.50 
1.72 

0.60 
0.65 

0.16 
0.17 

.    .    . 

Franconian  wines,  white    .... 

0.9943 

6.65 

1.20 

0.60 

0.015 

"              "       red     ... 

0.9932 

8.00 

1.50 

0.47 

6.20 

The  following  analyses  of  French  wines  are  from  the  official  report  of 
the  Laboratoire  Municipal  at  Paris  for  1883  :f 


GRAMMES  PER  LITRE. 

>> 
•°d 

"3 

d 

*3.tf 

J 

a 

og 

11 

"8° 

"xS 

xtract 
vacuo 

j 

' 

I 

'S  Oj  O 

3*1 

a>  <n  U) 

30 

If 

«4 

H 

W 

H 

pq 

* 

Bordeaux  wines  St  Estephe  1878 

11  1 

224 

283 

220 

1  SI 

1  50 

049 

2  96 

"        Medoc   1880    

103 

190 

237 

205  1   142 

0  9 

076 

396 

"        Latour,  1878    

9.5 

17.0 

22.8 

2.14 

2.07 

1.1 

0.50 

4.06 

"       Chateau  Margaux,  1878  

10.2 

236 

1  5 

0.48 

11  2 

230 

30  i 

2  34 

244 

1  3 

0  63 

"             "       (white,)  Sauterne,  1880   

10.4 

16.0 

3.6 

0.53 

Burgundy  wines,  Chambertin,  1882         

11  5 

233 

295 

1.77 

857 

14 

055 

"       (white  )  Chablis  1878     .  .  . 

11.0 
7.8 
9  1 

16.7 
20.2 
207 

0.6 
1.2 
1.1 

0.38 
0.37 
0.48 

Lower  Burgundy,  average  of  7  analyses  
Upper  Burgundy,  average  of  25  analyses  

*  Praxis  des  Nahrungsmittels  Chemiker,  1880,  p.  103. 
f  Deuxieme  Rapport  du  Laboratoire  Municipal,  Paris,  1884. 
14 


210 


FERMENTATION   INDUSTRIES. 


Of  sweet  and  fortified  or  treated  wines  the  following  analyses  are 
given  by  Konig.* 


9| 

«B  > 

\t 

OQ 

Alcohol  by 
weight. 

Extract. 

! 

Tartaric  acid. 

Glycerine. 

Albuminoids. 

1 

o 

o 
•s-d 

JS 
PH 

Sulphuric 
acid. 

Tokay  1868 

1.0879 
1.0588 
1.0849 
1.0691 
1.0574 
1.0126 
1.0125 
0.9966 
1.0111 
1.0018 
0.9952 
0.9924 
1.0519 

9.80 
10.29 
8.96 
13.23 
10.02 
16.28 
17.93 
16.73 
15.52 
15.34 
18.66 
16.34 
10.97 

26.36 
18.34 
23.64 
21.23 
16.91 
8.83 
8.83 
4.94 
5.45 
5.33 
3.78 
2.68 
14.46 

22.11 
14.99 
21.74 
16.57 
15.52 
4.88 
6.42 
3.48 
3.78 
3.39 
1.88 
0.52 
11.82 

0.509 
0.517 
0.512 
0.416 
0.555 
0.538 
0.451 
0.396 
0.470 
0.489 
0.438 
0490 
0.502 

0.212 
0.234 
0.162 
0.248 
0.298 
0.168 
0.145 
0.298 
0.457 
0.291 
0.506 
0.560 

0.427 
0.389 
0.231 
0.217 
0.151 
0.094 
0.200 
0.150 
0.231 
0.144 
0.200 
0.200 
0.237 

0.343 
0.300 
0.409 
0.239 
0-312 
0.208 
0.236 
0.270 
0.418 
0.376 
0.483 
0.650 
0.563 

0.050 
0.074 
0.057 
0.042 
0.036 
0.035 
0.032 
0.024 
0.024 
0.082 
0.032 
0.038 
0.058 

0.061 
0.022 
0.035 
0.026 
0.073 
0.039 
0.019 
0.087 
0.155 
0.081 
0.184 
0.268 
0.044 

Ruster  Ausbruch  1872              ... 

Malaga,  1872  

Muscat  wine  1872   

Port  wine  (white)  1860 

Port  wine  (red)  1865 

Marsala  (Ingham)      .      .  .      . 

Marsala  (Woodhouse) 

Madeira  1868    ...            

Sherry  1870 

Sherry,  Amontillado  1870  

Samos  'wine  1872 

Two  analyses  of  champagne  and  effervescing  wine  are  also  given  by 
Konig  :f 


>, 

f^ 

'i 

o 

8 

03 

1 

.S 

§ 

" 
"'d 

cC  [> 

X  ^b 

oi 

ij 

t* 

5n 

| 

"p/d 

fl« 

"o  °3 

o  i> 

S 

1 

^ 

8 

3 

0)  fcl 

§* 

^3 

bo 

N 

ja 

4 

o  ~ 

i—  i   ® 

• 

00 

H 

02 

H 

O 

5 

1 

£ 

i 

Champagne,  Carte  Blanche  .... 
Effervescing  Rhine  wine    

1.0433 
1.0374 

9.51 
9.80 

13.96 

10.88 

11.53 

8.49 

0.581 
0.566 

0.084 
0.062 

0.219 
0.294 

0.134 
0.171 

0.027 
0.034 

0.017 
0.026 

Of  American  wines  a  large  number  have  been  investigated  by  the 
United  States  Bureau  of  Agriculture.  A  selection  from  those  analyzed  by 
H.  B.  Parsons  %  in  1880  is  given  : 


, 

H 

3 

kh 

.• 

£.i 

pQ  o3 

2  t> 

'o  ° 

I 

<c? 

IS 

o| 

1 

$ 

§§ 

5-s 

5^ 

02 

1° 

is 
H 

i 

O 

H~ 

Is 

"o  ri 

Dry  red  it?mes  : 

Concord,  Virginia,  1879  

09953 

883 

1108 

210 

0174 

Trace. 

0.709 

0.452 

0.206 

Clinton,  Virginia  1879 

09950 

982 

1231 

236 

0238 

None 

0784 

0.513 

0217 

Norton's  Virginia,  1879  .  .  . 

09937 

10.21 

12.77 

2.88 

0.298 

Trace. 

0.772 

0.377 

0.316 

Ives's  Seedling,  Virginia,  1879    .... 

0.9944 

8.68 

10.82 

2.18 

0.247 

Trace. 

0.723 

0.512 

0.169 

Sonoma    Red    Mission,     California, 

1879  . 

09968 

7.99 

10.03 

2.42 

0.428 

None. 

0.722 

0.301 

0.337 

Sonoma  Red    Zinfandel,   California, 

1879  .... 

0  9962 

780 

978 

243 

0255 

Trace 

0693 

0391 

0242 

Concord  Bouquet,  New  Jersey  .... 

0.9928 

9.84 

12.31 

2.18 

0.141 

0.71 

0.741 

0.272 

0.375 

Nahrungs-  und  Genussmittel,  vol.  ii.  p.  463.  f  Ibid.,  p.  464. 

United  States  Bureau  of  Agriculture,  Bulletin  No.  13,  pp.  334-338. 


PRODUCTS. 


211 


h» 

cstS 

P 

CO 

Alcohol  by 
weight. 

Alcohol  by 
volume. 

Extract. 

4 

Glucose. 

Total  acid  as 
tartaric. 

Fixed  acids  as 
tartaric. 

Volatile  acid  as 
acetic. 

Dry  white  wines  : 
Brocton  Catawba  New  York  

0.9890 
0.9911 
0.9H'J2 
0.9914 
0.9932 
0.9921 
0.9928 
0.9928 
0.9911 
0.9918 
0.9920 
0.9935 

1.0508 
1.0213 
1.0339 
1.0074 
0.9949 
0.9942 
1.0052 
1.0174 
1.0102 
1.0207 
1.0338 
1.0512 
1.0101 
1.0245 
1.0440 
1.0515 
1.0320 
1.0404 
0.9948 

1228 
888 
10.25 
10.46 
9.35 
10.37 
7.78 
9.14 
9.52 
9.64 
9.36 
8.30 

10.00 
13.67 
12.68 
13.87 
17.62 
13.42 
16.06 
9.26 
8.26 
8.41 
11.68 
10.71 
9.89 
17.33 
8.96 
9.71 
8.73 
9.06 
10.72 

15.30 
11.08 
12.77 
13.05 
11.70 
12.96 
9.80 
11.44 
11.26 
12.05 
11.70 
10.38 

13.24 
17.59 
16.52 
17.59 
22.09 
16.80 
20.33 
11.87 
10.82 
10.82 
15.21 
14.18 
12.58 
18.58 
11.79 
12.87 
11.35 
11.87 
13.43 

2.09 
1.67 
1.63 
1.90 
1.88 
1.99 
1.60 
1.82 
1.47 
1.72 
1.58 
1.67 

17.04 
10.69 
14.18 
6.83 
4.89 
3.91 
6.42 
7.78 
13.31 
8.47 
14.49 
16.71 
7.23 
31.34 
14.41 
16.52 
12.07 
14.13 
3.39 

0.121 
0.129 
0.113 
0.199 
0.255 
0.185 
0.146 
0.150 
0.139 
0.221 
0.196 
0.193 

0.139 
0.309 
0.345 
0.166 
0.219 
0.198 
0.428 
0.149 
0.110 
0.130 
0.152 
0.113 
0.211 
0.371 
0.196 
0.101 
0.118 
0.132 
0.108 

Trace. 
Trace. 
Trace. 
Trace. 
Trace. 
None. 
Trace. 
Trace. 
Trace. 
Trace. 
Trace. 

11.80 
7.44 
11.39 
4.84 
3.33 
2.20 
3.53 
6.51 
12.02 
7.23 
11.00 
15.22 
4.01 
25.37 
12.48 
15.31 
10.27 
11.56 
1.31 

0.542 
0.772 
0.728 
0.545 
0.562 
0.732 
0.562 
0.619 
0590 
0.696 
0.726 
0.619 

0.828 
0.705 
0.508 
0.689 
0.476 
0.573 
0.626 
0.885 
0.880 
0.779 
0.595 
0.714 
0.668 
0753 
0.489 
0.628 
0.799 
0.758 
0.925 

0.470 
0.387 
0.424 
0.302 
0.332 
0.317 
0.302 
0.248 
0.227 
0.210 
0.212 
0.317 

0.600 
0.347 
0.348 
0.209 
0.271 
0.232 
0.418 
0.295 
0.447 
0.470 
0.296 
0.471 
0.318 
0.421 
0.310 
0.465 
0.355 
0.323 
0.346 

0.068 
0.308 
0.243 
0.194 
0.184 
0.332 
0.208 
0.289 
0.290 
0.389 
0.411 
0.242 

0.182 
0.286 
0.128 
0.323 
0.164 
0.273 
0.166 
0.472 
0.346 
0.247 
0.239 
0.194 
0.280 
0.266 
0.143 
0.130 
0.355 
0.348 
0.463 

Missouri  Catawba,  Missouri   
Ohio  Catawba  Ohio 

Rulander  Virginia,  1880  

Delaware,  Virginia,  1880    
Taylor  Virginia  1880     

Herbemont  Virginia  1880    

Dry  Muscat  California 

White  Zinfa'ndel  California    

Riesling  California 

Gutedel  California     

Sonoma  Mission,  California,  1879  .  .  . 
Sweet  wines': 
Brocton  Port  New  York             .  . 

Speer's  Port  New  Jersey                . 

Port,  Los  Angeles,  California  
New  York  Sherry 

Speer's  Sherry,  New  Jersey  

California  Sherry  
Marsala  California 

"  Eclipse"  Extra  Dry  Champagne    . 
"  Gold  Seal"Champagne,  New  York 
Cook's  "  Imperial''  Champagne    .  . 
Sweet  Catawba,  Bass  Island,  Ohio    . 
Sweet  Catawba,  Brocton,  New  York 
Sweet  Catawba,  Iowa,  1871  
Sweet  Muscatel  California 

California  Angelica        ..... 

Brocton  Sweet  Regina    

Sweet  Delaware  1879  

Scuppernong  Sweet  1878 

Scuppernong,  Dry,  1879  

Side-products. — The  first  of  these  is  the  marc  of  the  grapes,  separated 
from  the  must  in  the  original  pressing  of  the  grapes,  or  left  when  the  fer- 
menting must  is  drained  from  it.  This  consists  of  the  stems,  skins,  and 
stones  of  the  grapes.  If  the  marc  instead  of  being  washed  out  with  water 
has  been  merely  pressed,  it  still  contains  sufficient  must  to  allow  of  its  being- 
used  in  the  manufacture  of  petiotized  wine.  Besides  this,  the  marc  serves 
for  a  great  variety  of  purposes.  It  is  fermented  for  brandy  ;  it  is  used  with 
sheet-copper  in  the  manufacture  of  verdigris  ;  it  is  used  to  start  the  fermen- 
tation in  vinegar-making ;  as  cattle-food ;  when  dried,  as  fuel  or  for  fertil- 
izing purposes ;  the  tannic  acid  is  extracted,  or  it  is  used  direct  in  producing 
black  colors,  and  for  other  minor  applications. 

The  second  and  more  valuable  side-product  is  the  deposit  formed  on  the 
bottom  and  sides  of  the  casks  in  which  the  fermentation  takes  place.  That 
on  the  bottom  of  the  casks  is  called  "lees."  It  contains  from  thirty  to 
forty  per  cent,  of  vegetable  matter  (from  the  yeast-cells  depositing),  the  re- 
mainder being  tartrates,  sulphates,  (in  plastered  wines),  alumina,  phosphoric 
acid,  etc.  Its  composition  is  greatly  altered  by  "plastering"  the  wine,  in 
which  case  the  tartrate  exists  chiefly  as  the  neutral  calcium  tartrate  instead 
of  the  acid  potassium  salt.  The  crystalline  crust  that  forms  on  the  sides 
of  the  vessels  used  for  fermentation  is  called  "  argol,"  or  crude  tartar.  It 
varies  somewhat  in  composition,  the  tartaric  acid  ranging  from  forty  to 
seventy  per  cent,  and  being  always  present,  chiefly  as  the  acid  potassium 
tartrate.  From  this  crude  tartar  is  prepared,  by  extraction  with  boiling 
water,  filtering,  and  crystallizing,  "  cream  of  tartar."  This,  however,  still 


212 


FERMENTATION   INDUSTRIES. 


FIG.  64. 


contains  some  calcium  tartrate  mixed  with  the  acid  potassium  salt,  the 
amount  ranging  from  two  to  nine  per  cent. 

TV.  Analytical  Tests  and  Methods. 

In  1884  the  Imperial  German  Health  Office  appointed  a  commission  of 
experts  to  report  upon  the  best  uniform  methods  for  the  analysis  of  wines. 
The  methods  agreed  upon  by  that  commission  are  very  generally  adopted 
now  in  Germany,  and  largely  used  elsewhere  in  guiding  wine  analysts. 
These  official  methods  have  been  fully  described  and  explained  in  a  little 
work  entitled  "  Weinanalyse,"  by  Dr.  Max  Barth,  Leipzig,  1884. 

The  specific  gravity  of  the  wine  is  determined  either  by  the  pyknometer 
(specific  gravity  bottle)  or  by  the  Westphal  balance  (see  p.  80),  the  readings 
of  which  have  been  compared  with  those  of  the  specific  gravity  bottle.  In 
the  case  of  champagnes  and  effervescing  wines,  as  was  the  case  with  beer,  the 
carbonic  acid  must  be  got  rid  of  as  far  as  possible  before  taking  the  specific 
gravity  readings. 

The  alcohol  is  determined  by  the  direct  distillation,  as  described  on  p. 
200.  Wines  that  have  a  tendency  to  foam  have  a  little  tannin  (.1  gramme) 
added.  If  one  hundred  cubic  centimetres  of  the  sample  is  taken,  sixty  cubic 
centimetres  only  need  be  collected,  and  will  contain  all  the  alcohol.  This 
is  then  diluted  to  nearly  one  hundred  cubic  centimetres,  cooled,  uniformly 
mixed,  and  then  brought  exactly  to  the  100-cubic-centimetre  mark,  mixed 
again,  and  the  specific 
gravity  taken.  The 
form  of  apparatus  best 
adapted  for  this  deter- 
mination of  alcoholic 
strength  of  wines  and 
liquors  is  shown  in 
Fig.  64.  For  the 
rapid  determination 
of  the  alcoholic 
strength  of  wines  va- 
rious forms  of  appa- 
ratus have  been  de- 
vised, such  as  the 
vaporimeter  of  Geiss- 
ler,  in  which  the  va- 
por-tension of  an  al- 
coholic liquid  exerted 
upon  a  column  of 
mercury  is  made  to 
indicate  its  percentage 
strength  in  alcohol, 
the  ebullioscope  of 
Tabarie,  of  Malligand 
and  Vidal,  and  of 
Amagat,  which  de- 
pend upon  the  obser- 
vation of  the  boiling-points  of  a  spirituous  liquor  as  determining  the  amount 
of  alcohol  contained.  None  of  these  can  be  said  to  have  scientific  accuracy, 


ANALYTICAL  TESTS   AND   METHODS.  213 

as  wine  is  not  merely  a  mixture  of  alcohol  and  water,  but  contains  other 
constituents  which  affect  the  results  in  either  case. 

The  extract  determination.  Here  the  direct  weighing  of  the  residue 
after  evaporation  is  preferred  to  the  indirect  method,  fifty  cubic  centimetres 
of  the  wine,  measured  at  15°  C.,  are  to  be  evaporated  on  the  water-bath  in  a 
platinum  dish  (according  to  the  German  wine  commission,  this  dish  should 
be  eighty-five  millimetres  in  diameter,  twenty  millimetres  in-height,  sev- 
enty-five cubic  centimetres  in  capacity,  and  should  weigh  about  twenty 
grammes),  and  the  residue  dried  for  two  and  a  half  hours  in  a  double-walled 
water  drying  oven.  In  the  case  of  wines  containing  more  than  .5  per  cent, 
sugar,  a  smaller  quantity  must  be  taken  and  suitably  diluted,  so  that  the 
extract  shall  not  weigh  more  than  1.0  to  1.5  grammes.  In  this  method,  the 
loss  of  glycerine  by  evaporation  is  trifling.  The  indirect  method  for  deter- 
mining the  extract  is  very  like  that  described  under  beer  (see  p.  200)  as 
O'Sullivan's  method,  except  that  with  wine  we  divide  the  excess  of  specific 
gravity  observed  over  1000  by  4.6  instead  of  3.86,  as  the  solids  of  wine 
have  a  higher  solution  density  than  those  of  extract  of  malt.  Or  with  the 
specific  gravity  of  the  de-alcoholized  liquid  we  may  get  the  extract  percentage 
from  Hager's  tables,  which  are  analogous  to  those  of  Schultze  for  malt 
extracts  before  referred  to. 

The  ash  percentage  can  be  obtained  by  incineration  of  the  evaporated 
extract  above  referred  to. 

To  determine  the  percentage  of  glycerine,  one  hundred  cubic  centimetres 
of  the  wine  are  evaporated  down  to  about  ten  cubic  centimetres  in  a  spacious 
porcelain  dish ;  some  sand  and  milk  of  lime  are  then  added  till  the  reaction 
is  strongly  alkaline  and  the  mixture  evaporated  almost  to  dryness.  The 
residue  is  next  treated  with  fifty  centimetres  of  ninety-six  per  cent,  alcohol, 
warmed  and  stirred  on  the  water-bath,  and  the  solution  obtained  then  passed 
through  a  filter.  The  insoluble  matter  is  washed  with  successive  small  por- 
tions of  hot  alcohol  (ninety-six  per  cent.),  of  which  fifty  to  one  hundred  and 
fifty  cubic  centimetres  will  as  a  rule  suffice,  so  that  the  entire  filtrate  will  be 
from  one  hundred  cubic  centimetres  to  two  hundred  cubic  centimetres.  The 
alcoholic  extract  is  now  evaporated  to  a  viscous  consistency,  and  the  residue 
taken  up  with  ten  cubic  centimetres  of  absolute  alcohol ;  this  solution  is 
mixed  with  fifteen  cubic  centimetres  of  ether  in  a  stoppered  flask  and  the 
mixture  allowed  to  stand  until  clear.  The  clear  liquid  is  decanted  or  filtered 
into  a  light  tared  glass  vessel,  carefully  evaporated,  and  the  residue  dried 
for  one  hour  in  the  water-bath.  It  is  then  cooled  and  weighed.  In  the 
case  of  sweet  wines  (containing  more  than  five  per  cent,  of  sugar),  only  fifty 
cubic  centimetres  of  the  wine  are  taken  for  the  estimation  of  the  glycerine ; 
sand  and  lime  are  added,  and  the  mixture  is  warmed  on  the  water-bath. 
After  cooling  it  is  treated  with  one  hundred  cubic  centimetres  of  ninety-six 
per  cent,  alcohol,  the  precipitate  formed  allowed  to  settle,  the  solution  fil- 
tered, the  insoluble  matter  washed  with  spirit,  and  the  alcoholic  filtrate 
treated  as  above  described. 

To  estimate  the  sugar  in  wine,  Fehling's  solution  is  used,  as  the  sugar 
should  be  only  glucose.  After  neutralization  of  the  wine  with  sodium  car- 
bonate, the  determination  is  made  (using  the  separately  preserved  solutions 
for  Fehl ing's  mixture.  See  p.  159).  Strongly-colored  wines  must  be  first 
decolorized.  If  the  sugar  percentage  is  low,  it  is  done  with  purified  bone- 
black  ;  if  they  contain  over  .5  per  cent,  of  sugar,  bone-black  cannot  be  used 
because  of  its  absorptive  power,  and  basic  acetate  of  lead  must  be  substi- 


214  FERMENTATION   INDUSTRIES. 

tuted.  After  filtering,  the  wine  is  then  treated  with  sodium  carbonate 
and  Fehling's  solution.  If  the  polarization  indicates  the  presence  of  cane- 
sugar,  the  solution  must  be  inverted  (see  p.  158)  and  then  the  Fehling's  test 
applied  again,  and  the  cane-sugar  calculated  from  the  difference  in  the  two 
readings.  The  Fehling's  test  is  best  carried  out  gravimetrically,  and  from 
the  weight  of  reduced  copper  the  corresponding  amount  of  glucose  can  be 
obtained  from  the  tables. 

The  polarization,  which  is  essential  in  the  case  of  heavy  wines  to  indicate 
the  nature  of  the  sugar  contained,  is  carried  out  as  follows  :  With  white 
wines,  to  sixty  cubic  centimetres  of  the  wine  are  added  three  cubic  centi- 
metres of  the  basic  acetate  of  lead  solution  and  the  precipitate  filtered  off  on 
a  dry  filter.  To  31.5  of  the  filtrate  is  added  1.5  cubic  centimetres  of  a  satu- 
rated solution  of  sodium  carbonate  and  the  solution  again  filtered  and  the 
polarization  tube  filled  with  the  filtrate.  The  dilution  of  the  original  wine 
in  this  case  is  10  : 11.  With  red  wines,  sixty  cubic  centimetres  of  the  wine 
are  treated  with  six  cubic  centimetres  of  the  lead  solution,  and  to  thirty-three 
cubic  centimetres  of  the  filtrate  three  cubic  centimetres  of  the  saturated 
sodium  carbonate  solution  added,  the  solution  filtered  and  polarized.  The 
dilution  here  is  5:6.  This  diluted  solution  is  observed  in  the  220- 
millimetre  tube  of  the  polariscope,  and  large  and  accurate  instruments  are 
necessary. 

The  free  adds  (total  acid-reacting  constituents  of  the  wine)  are  estimated 
in  ten  to  twenty  cubic  centimetres  of  the  wine  by  means  of  one-third  or 
one-tenth  normal  alkali.  Any  considerable  quantity  of  carbonic  acid  to  be 
first  removed  by  shaking.  The  "  free  acids"  to  be  calculated  into  and  given 
as  tartaric  acid  (C4H6O6). 

The  volatile  acids  are  determined  by  steam  distillation  and  calculated  as 
acetic  acid  (C2H4O2)- 

The  quantity  of  non-volatile  acids  calculated  as  tartaric  is  found  by  sub- 
tracting the  equivalent  of  the  acetic  acid  in  tartaric  acid  from  the  free  acids 
previously  determined. 

These  three  determinations  are  all  that  are  usually  made  in  wine  analyses. 
If  a  special  qualitative  test  for  free  tartaric  acid  is  desired  or,  in  case  it  be 
shown  to  be  present  in  appreciable  quantity,  a  quantitative  method  for  its 
determination,  they  can  be  made  by  Nessler's  method,  for  details  of  which 
the  reader  is  referred  to  Earth's  "  Weinanalyse"  before  mentioned,  or  to  a 
summary  of  its  methods  in  the  "  Journal  of  the  Society  of  Chemical  Indus- 
try," 1885,  p.  553. 

The  tannin  may  be  determined  by  Neubauer's  method  with  permanganate 
of  potash,  or  approximately  by  the  following  procedure :  the  free  acids  in 
ten  cubic  centimetres  of  the  wine  are  neutralized  with  standard  alkali,  after 
which  one  cubic  centimetre  of  a  forty  per  cent,  solution  of  sodium  acetate 
is  added,  and  finally  a  ten  per  cent,  solution  of  ferric  chloride,  drop  by  drop, 
and  avoiding  excess.  One  drop  of  this  solution  suffices  for  the  precipitation 
of  every  .05  per  cent,  of  tannin. 

Salicylic  Acid. — To  detect  this  acid,  one  hundred  cubic  centimetres  of  the 
wine  are  shaken  repeatedly  with  chloroform,  the  latter  is  evaporated,  and  the 
aqueous  solution  of  the  residue  tested  with  very  dilute  ferric  chloride  solu- 
tion. For  the  purpose  of  an  approximate  quantitative  estimation,  it  is  suffi- 
cient, on  the  evaporation  of  the  chloroform,  to  once  recrystallize  the  residue 
from  chloroform  and  weigh  it. 

One  of  the  most  important  questions  that  arises  in  the  examination  of 


ANALYTICAL  TESTS   AND   METHODS.  215 

red  wines  is  as  to  the  genuineness  of  the  coloring  matter,  as  both  vegetable 
and  artificial  dye  colors  have  been  used  for  years  to  imitate  the  natural  color- 
ing matter  in  the  manufacture  of  factitious  red  wines.  Very  elaborate 
schemes  for  the  recognition  of  foreign  coloring  matters,  including  both  the 
vegetable  coloring  matters  like  dye-woods  and  color-yielding  berries  and  the 
large  number  of  the  newer  coal-tar  colors,  have  been  given  by  Gautier  * 
and  by  Chas.  Girard,f  the  director  of  the  Laboratoire  Municipaljn  Paris, 
to  which  we  can  only  give  references.  The  coloring  matters  most  generally 
used  to  imitate  the  natural  pigment  of  the  grape-skins  are  fuchsine,  coch- 
ineal, alderberry,  hollyhock,  and  logwood.  Dupre  tests  the  coloring  matter 
as  follows  :  Cubes  of  jelly  are  prepared  by  dissolving  one  part  of  gelatine  in 
twenty  parts  of  hot  water  and  pouring  the  solution  in  moulds  to  set.  These 
are  immersed  in  the  wine  under  examination  for  twenty-four  hours,  then 
removed,  slightly  washed,  and  examined.  Pure  wine  will  color  the  gelatine 
only  very  superficially  ;  the  majority  of  other  coloring  matters  (fuchsine, 
cochineal,  logwood,  Brazil-wood,  litmus,  and  indigo)  penetrate  more  readily, 
passing  to  the  very  centre  of  the  cube.  A  confirmative  test  can  also  be 
made  with  the  dialyzer.  The  coloring  principle  of  pure  wine  when  sub- 
jected to  dialysis  does  not  pass  through  the  animal  membrane  to  any  decided 
extent,  while  the  color  of  logwood,  Brazil-wood,  and  cochineal  easily  dialyzes. 
If  rosaniline  colors  alone  are  to  be  tested  for,  the  procedure  of  Faliere  as 
improved  by  Nessler  and  Barth  can  be  followed.  One  hundred  cubic  centi- 
metres of  the  wine  are  shaken  in  a  stoppered  jar  with  thirty  cubic  centi- 
metres of  ether  and  five  cubic  centimetres  of  strong  ammonia,  and  then 
twenty  cubic  centimetres  of  the  ethereal  layer  removed  with  a  pipette  and 
evaporated  in  a  capsule  containing  a  thread  of  white  wool  five  centimetres 
in  length.  Similar  threads  are  dyed  with  known  quantities  of  magenta,  and 
from  a  comparison  of  tints  the  amount  of  the  added  coloring  matter  in  the 
wines  is  inferred.  This  test  will  detect  minute  quantities  of  fuchsine  or  ani- 
line red.  If  the  same  test  be  carried  out  without  adding  ammonia,  the  acid 
rosaniline  colors  and  similar  dyes  will  be  extracted.  The  fact  that  pure  wine 
color  is  not  changed  or  decolorized  by  nascent  hydrogen  (zinc  and  acid), 
while  most  of  the  aniline  dyes  are  decomposed  by  it,  is  also  used  as  a  test. 

D.   MANUFACTURE  OF  DISTILLED  LIQUORS,  OR  ARDENT  SPIRITS, 

This  industry  differs  radically  from  the  two  fermentation  industries 
already  described,  firstly,  in  that  the  effort  is  made  to  push  the  fermentation 
to  the  fullest  possible  limit,  so  that  the  maximum  quantity  of  alcohol  may 
be  produced,  and,  secondly,  in  that  this  product  of  fermentation  is  then  dis- 
tilled, and  it  may  be  redistilled  in  order  to  get  a  distillate  richer  in  alcohol 
than  the  fermentation  product  itself  can  be.  The  end  to  be  attained  may 
be  either  the  production  of  an  alcoholic  beverage  as  the  product  of  distilla- 
tion or  of  raw  spirit,  which  takes  name  from  the  material  used,  as  "  grain 
spirit,"  "  potato  spirit,"  "  corn  spirit,"  etc.  From  this  raw  spirit  by  the 
processes  of  rectification  are  obtained  the  "  rectified  spirit"  used  as  the  basis 
of  the  manufacture  of  various  alcoholic  beverages  and  as  a  solvent  in  vari- 
ous manufacturing  processes,  and  by  purification  and  dehydration  the  abso- 
lute ethyl  alcohol  of  the  chemist. 

*  Wynter  Blyth,  Foods,  Composition  and  Analysis,  p.  464. 
f  Deuxieme  Rapport  du  Laboratoire  Municipal. 


216  FERMENTATION    INDUSTRIES. 

I.  Raw  Materials. 

These  may  be  divided  into  three  classes :  First,  alcoholic  liquids,  them- 
selves the  product  of  fermentation, — these  require  only  to  be  submitted  to 
distillation  in  order  to  yield  the  stronger  spirit ;  second,  solid  and  liquid 
materials  containing  some  variety  of  sugar,  whether  cane-sugar,  grape- 
sugar,  or  maltose,  which  are  directly  or  indirectly  fermentable ;  and,  third, 
starch-containing  cereals  and  all  materials  capable  under  the  influence  of 
diastase  or  dilute  acids  of  hydrolysis  and  the  production  of  a  fermentable 
sugar. 

1.  ALCOHOLIC  LIQUIDS  (  Wines). — The  distillation  of  wines  is  followed 
for  the  production  of  an  alcoholic  beverage  (brandy)  which  takes  to  some 
degree  its  flavor  and  bouquet  from  the  wines  used  in  the  distillation.     While 
factitious  brandies  are  largely  made  from  grain  or  potato  spirit,  the  true 
product  from  wine  is  always  regarded  as  superior. 

The  manufacture  of  wine  brandy  has  been  chiefly  carried  out  in  France, 
and  in  minor  degree  in  Spain  and  Portugal.  Within  recent  years  California 
wines  have  also  been  used  for  the  manufacture  of  brand  ies.  The  French  wines 
which  are  used  are  largely  those  of  the  departments  Charente  and  Charente- 
Inferieure,  in  the  southwest  of  France,  and  the  product  is  all  known  as 
Cognac  brandy. 

White  wines  are  said  to  yield  a  superior  spirit  to  that  obtained  from  red 
wines,  and  older  wines  better  than  newer  ones.  About  eight  and  a  half 
hectolitres  of  wine  are  needed  to  produce  one  hectolitre  of  brandy.  Because  of 
the  ravages  of  the  Phylloxera  insect,  the  manufacture  of  genuine  wine  Cognac 
has  decreased  enormously  in  France  in  recent  years,  while  the  manufacture  of 
factitious  Cognac  has  correspondingly  increased.  Thus  we  find  it  officially 
stated  *  that  the  production  of  alcohol  from  wine  in  France  had  decreased 
from  530,000  hectolitres  in  1875  to  14,678  hectolitres  in  1883. 

The  marc  of  the  grapes,  as  already  stated  (see  p.  211),  is  also  utilized  in 
the  manufacture  of  an  inferior  grade  of  brandy,  known  in  France  as  eau 
de  vie  de  marc.  The  lees,  or  sediment,  of  the  wine-casks  are  also  used  in  this 
same  way.  This  brandy  is  not  necessarily  sold  for  consumption,  but  is  used 
to  strengthen  the  alcoholic  percentage  of  wines  in  which  fermentation  is  to 
be  arrested. 

2.  SUGAR-CONTAINING  RAW  MATERIALS. — The  most  important  sugar- 
yielding  materials  cultivated  on  a  large  scale,  it  will  be  remembered,  are  the 
sugar-cane  and  the  sugar-beet.     The  sugar-canes  are  not  used  directly  for 
the  production  of  spirits  (except  in  the  case  of  accidental  souring),  and  the 
"  bagasse/'  although  still  containing  saccharine  juice,  is  too  bulky,  and 
hence  is  at  once  burned  as  fuel,  but  the  molasses  obtained  on  so  large  a  scale 
in  the  extraction  of  raw  sugar  is  a  most  valuable  material  for  the  purpose. 
Throughout  both  the  West  Indies  and  the  East  Indies  enormous  quantities 
of  this  molasses  are  fermented  and  the  resultant  product  distilled  for  rum. 
Even  the  sugar-scums  obtained  in  the  defecating  and  concentrating  of  the 
sugar  juice  are  fermented,  and  produce  an  inferior  grade  of  rum. 

With  the  sugar-beet,  both  the  beet  itself  and  the  beet-molasses  are  util- 
ized, the  former  being  used  in  France  and  the  latter  in  both  France  and 
Germany.  Sweet  fruits,  the  juice  of  which  is  rich  in  sugar,  also  serve  as 
raw  materials  for  the  spirit  industry.  Thus  peaches,  plums,  and  cherries 

*  Deuxieme  Kapport  du  Laboratoire  Municipal,  p.  272. 


PROCESSES   OF   MANUFACTURE.  217 

are  much  used  in  different  countries  for  the  manufacture  of  fruit  brandy, 
and  the  fermented  juice  of  the  date-palm  in  the  East  Indies  and  of  the 
plantain  in  the  West  Indies  both  serve  for  the  distillation  of  an  alcoholic 
beverage. 

3.  STARCH-CONTAINING  RAW  MATERIALS. — This  list  includes  the 
main  sources  for  the  distillation  of  spirits,  as  the  high  percentage  of  starch 
in  many  cereals,  ranging  from  sixty  to  seventy-seven  per  cent^  the  ease 
with  which  the  starch  can  be  converted  into  fermentable  sugar  under  the 
influence  of  diastase  or  dilute  acids,  and  the  cheapness  of  these  starchy 
products  of  nature  all  combine  to  make  them  for  most  countries  the  cheapest 
and  best  materials  for  the  spirit  industry.  In  the  United  States,  the  three 
cereals  used  almost  exclusively  for  the  manufacture  of  distilled  liquors  are 
corn,  rye,  and  malted  barley ;  in  England,  barley,  both  raw  and  malted, 
rye,  corn,  and  rice ;  in  Germany  the  potato  is  almost  the  only  starchy 
material  used.  The  composition  of  the  several  cereals  showing  their  rela- 
tive percentage  of  starch  was  given  on  p.  169. 

n.  Processes  of  Manufacture. 

1.  PREPARATION  OF  THE  WORT. — In  England  and  the  United  States, 
where  grain  spirit  is  mainly  manufactured,  the  first  process  is  that  of  sac- 
charifying the  starch  of  the  grain.  In  the  special  cases  where  malted  grain 
alone  is  used,  the  mash  process  somewhat  resembles  that  already  described 
under  beer-brewing.  Most  distillers,  however,  use  mixtures  of  raw  and 
malted  grain,  in  which  the  raw  largely  predominates,  being  often  ten  to 
one  or  even  more,  as  a  very  small  quantity  of  diastase  can  be  made  to  con- 
vert a  large  amount  of  starch  into  maltose  or  fermentable  sugar.  It  is 
stated,  moreover,  that  the  yield  of  spirit  is  larger  when  several  kinds  of 
grain  are  mixed  than  when  one  kind  is  used  singly.  The  mixture  of  raw 
and  malted  grain,  properly  ground,  is  put  into  the  mash-tub  (see  Fig.  62, 
p.  193)  with  water  at  150°  F.  and  agitated.  This  first  mashing  requires 
from  one  to  four  hours,  the  larger  the  quantity  of  raw  grain  used  the  longer 
being  the  time  required  for  mashing.  The  temperature  of  the  mixture  is 
kept  up  to  about  145°  F.  by  the  successive  additions  of  water  at  a  some- 
what higher  temperature  (190°  to  200°  F.).  The  object  of  the  distiller  in 
this  is  somewhat  different  from  that  of  the  beer-brewer.  He  wishes  to 
convert  the  whole  of  the  starch,  if  possible,  into  maltose,  which  is  directly 
fermentable  by  the  action  of  yeast,  while  the  dextrine  is  not,  so  he  must 
mash  at  not  much  over  146°,  which  it  will  be  seen  from  Fig.  61  (p.  187) 
is  the  limit  above  which  the  maltose  production  begins  to  decrease.  When 
the  gelatinization  of  the  starch  is  complete,  the  temperature  of  the  mash 
may  go  slightly  higher.  By  keeping  within  this  limit  of  temperature,  a 
minimum  of  diastase  from  the  small  admixture  of  malt  will  gradually 
change  not  only  the  starch,  but  bring  about  a  hydration  of  the  residual 
dextrine,  converting  it  into  maltose.  When  the  wort  has  acquired  its  maxi- 
mum density,  as  found  by  the  saccharometer,  it  is  drawn  off,  and  fresh 
water  at  about  190°  F.  is  run  upon  the  residue  in  the  mash-tub  and  allowed 
to  infuse  with  it  for  one  or  two  hours.  This  second  wort  is  then  added  to 
the  first.  A  third  weak  wort  is  often  obtained,  and  used  to  infuse  new 
lots  of  grain.  The  mash  is  then  cooled  down  promptly  to  the  temperature 
required  for  fermentation  so  that  the  acetous  fermentation  may  not  set  in. 

It  is  stated  that  in  this  method  of  direct  mashing  ten  per  cent,  of  the 


218  FERMENTATION    INDUSTRIES. 

starch  escapes  decomposition,  even  although  the  grain  may  be  taken  finely 
ground.  Hence  a  preliminary  warming  with  water  to  which  a  little  green 
malt  is  sometimes  added,  followed  by  heating  with  water  under  a  pressure 
of  several  atmospheres,  now  often  precedes  the  addition  of  the  main  quan- 
tity of  the  malt,  which  is  to  complete  the  conversion  of  the  starch  and  dex- 
trine into  maltose.  In  this  way  the  loss  may  be  reduced  from  ten  to  five 
per  cent. 

In  Germany  potatoes  constitute  the  chief  raw  material  for  the  spirit 
manufacture.  They  contain  from  eighteen  to  twenty  per  cent,  of  starch 
only,  however,  while  the  cereals  contain  over  sixty  per  cent.  The  amount 
of  the  malt  needed  for  the  saccharification  of  the  starch  can  therefore  be  cor- 
respondingly reduced.  Instead  of  mashing  the  ground,  rasped,  or  chipped 
potatoes  in  open  mash-tubs  as  was  formerly  done,  they  are  now  first  steamed 
under  a  pressure  of  two  to  three  atmospheres,  whereby  the  starch-contain- 
ing cells  are  thoroughly  ruptured  and  the  starch  put  in  condition  to  be 
easily  acted  upon  by  the  diastase.  Among  the  forms  of  apparatus  based 
upon  this  principle  may  be  mentioned  those  of  Hollefreund,  Bohm,  Henze, 
and  Ellenberger.  In  that  of  Henze,  which  has  been  largely  adopted,  the 
potatoes,  after  steaming  under  a  pressure  of  several  atmospheres,  are  so  dis- 
integrated that  on  opening  a  valve  in  the  bottom  of  the  vessel  the  pulp  is 
forced  out  through  a  grating  in  a  thin  stream.  This  is  cooled,  mixed  with 
the  requisite  quantity  of  malt,  and  started  to  mashing.  In  the  Hollefreund 
and  in  the  Bohm  apparatus,  the  steaming,  disintegrating,  and  mashing  all 
take  place  in  the  same  closed  vessel,  the  malt  being  added  after  the  dis- 
integrated mass  has  been  properly  cooled  down.  Green  malt  is  found  to 
work  better  in  this  case  than  air  malt,  and  produces  more  alcohol. 

2.  FERMENTATION  OF  THE  WORT,  OR  SACCHARINE  LIQUID. — In  the 
case  of  mashing,  as  described  above,  either  with  grain  or  with  potatoes,  the 
wort  must  first  be  cooled  down  before  adding  the  yeast  and  starting  the 
fermentation.  The  yeast  used  is  a  surface  yeast,  and  either  fresh  brewer's 
yeast  or  compressed  yeast  (previously  softened  in  warm  water)  may  be  used. 
The  procedure  is  now  somewhat  different,  according  as  we  have  a  grain- 
mash  or  a  potato-mash  to  deal  with.  In  the  former  case,  using  a  thin  wort 
drained  from  the  exhausted  grain,  it  has  been  found  that  the  best  results 
are  obtained  when  the  temperature  during  fermentation  rises  to  about  33° 
or  34°  C.  (92°  to  94°  F.),  as  shown  in  Fig.  61  (see  p.  187) ;  in  the  latter 
case,  where  the  entire  mash,  solid  matter  and  all,  is  fermented,  the  fermenta- 
tion begins  at  a  much  lower  temperature,  and  the  heat  evolved  in  the  fer- 
mentation of  such  a  concentrated  wort  ultimately  carries  the  temperature  to 
the  same  maximum.  In  the  English  plan,  considerable  lactic  acid  forms 
because  of  the  higher  temperature,  and  this  is,  of  course,  at  the  expense  of 
the  alcohol  formation,  while  in  the  German  plan,  because  of  the  low  initial 
temperature  of  the  fermentation,  comparatively  little  lactic  acid  is  produced, 
and  when  the  higher  temperatures  are  reached  the  mixture  already  contains  so 
much  alcohol  that  the  lactic  acid  ferment  grows  with  considerable  difficulty. 

For  one  thousand  litres  of  grain-mash,  eight  to  ten  litres  of  brewer's 
yeast  or  one-half  kilo,  of  compressed  yeast  are  used ;  for  one  hundred  litres 
of  potato-mash,  one  to  two  litres  of  brewer's  yeast  or  three-fourths  to  one 
kilo,  of  compressed  yeast  are  needed. 

The  fermentation  is  sometime  divided  into  several  stages :  the  prelimi- 
nary fermentation,  in  which  the  yeast-cells  grow  without  much  alcohol 
formation ;  the  main  fermentation,  in  which  the  maltose  is  fermented ;  and 


PROCESSES   OF   MANUFACTURE.  219 

the  q/fer-fermentation,  in  which  the  dextrine  is  gradually  changed  into  mal- 
tose and  this  into  alcohol. 

The  time  of  fermentation  varies  from  three  to  nine  days,  but  it  is  carried 
on  until  the  density  of  the  liquid  ceases  to  lessen  or  attenuate,  which  is 
determined  by  the  saccharometer. 

The  coefficient  of  purity  of  a  fermentation  is  a  term  used  to  designate 
what  percentage  of  the  available  starchy  material  in  a  substance  has 
actually  undergone  the  pure  alcoholic  fermentation.  Thus,  the  reaction 
C6H10O5  -{-  H2O  =  2C2H6O  +  2CO2  demands  from  one  kilogramme  of 
starch  a  percentage  of  alcohol  equal  to  71.7  litres,  and  such  a  yield  from 
one  kilogramme  of  fermented  material  would  indicate  a  purity  coefficient  of 
one  hundred  per  cent.  A  percentage  yield  equal  to  sixty  litres  of  alcohol 
from  one  kilo,  of  material  would  give  a  purity  coefficient  of  83.7  per  cent. 

The  use  of  hydrofluoric  acid  or  ammonium  fluoride,  first  proposed  by 
Effront  as  an  antiseptic  and  indirect  aid  to  the  alcoholic  fermentation,  has 
become  quite  important  in  the  spirit  industry.  The  advantages  claimed  for 
its  use  are :  first,  by  preventing  the  losses  due  to  secondary  fermentation, 
the  alcohol  yield  is  increased ;  second,  this  yield  is  especially  maintained 
when  raw  materials  of  somewhat  inferior  quality  are  used,  when  without 
the  hydrofluoric  acid  the  yield  would  be  diminished ;  third,  the  develop- 
ment of  foaming  in  the  fermentation  is  in  large  degree  prevented. 

In  France,  the  juice  from  inferior  beets  instead  of  being  worked  for  the 
extraction  of  sugar  is  often  fermented  and  distilled.  The  juice  is  made 
slightly  acid  with  sulphuric  acid  to  prevent  any  viscous  fermentation,  and 
a  small  quantity  of  brewer's  yeast  is  added.  The  temperature  'of  the  fer- 
mentation is  from  20°  to  22°  C.,  and  the  process  is  usually  complete  in 
from  twenty-four  to  thirty-six  hours. 

The  use  of  the  molasses  obtained  in  the  extraction  of  the  raw  sugar, 
whether  from  the  sugar-beet  or  the  sugar-cane,  is,  however,  much  more 
common.  In  France  and  Germany,  where  the  beet-sugar  molasses  is  pro- 
duced in  large  quantities,  the  molasses  originally  marking  40°  to  48° 
Beaum6  is  diluted  to  8°  or  10°  Beaume,  and  sulphuric  acid  of  66°  is  added 
to  the  amount  of  1.5  per  cent,  of  the  molasses  taken.  This  neutralizes  the 
bases  of  the  beet-molasses  and  inverts  the  cane-sugar  present,  bringing  it 
into  fermentable  form.  Brewer's  yeast  is  then  added,  and  the  fermentation 
proceeds  rapidly.  The  temperature  ranges  from  22°  C.,  that  usually  chosen 
in  France,  where  more  dilute  solutions  are  fermented,  to  25°  to  30°  C.  in 
Germany,  where  the  concentration  is  usually  as  much  as  12°  B.  Two  hundred- 
weight of  molasses  at  42°  B.  will  furnish  about  six  gallons  of  pure  spirit. 

In  the  West  Indies,  notably  in  Jamaica,  the  cane-sugar  molasses  is 
similarly  utilized,  but  the  procedure  is  somewhat  different.  In  this  case  the 
addition  of  yeast  is  unnecessary,  as  the  nitrogenous  matters  present  suffice 
to  start  spontaneous  fermentation.  The  best  rum  is  that  gotten  from  the 
molasses  alone ;  a  second  grade  is  obtained  from  the  skimmings  and  "  sweet- 
waters"  which  accumulate  in  the  extraction  of  the  sugar.  To  these  is  added 
some  "  dander"  (fermented  wash,  deprived  by  distillation  of  its  alcohol  and 
much  concentrated  by  boiling),  which  acts  as  the  ferment  and  starts  the 
action.  Molasses  is  then  added  in  the  proportion  of  six  gallons  to  every 
hundred  gallons  of  the  fermenting  liquid  and  the  action  allowed  to  go  to 
completion.  One  hundred  gallons  of  this  mixture  when  distilled  should 
yield  twenty-five  gallons  of  "  low  wines"  or  one  gallon  of  proof  rum  for 
each  gallon  of  molasses  employed. 


220  FERMENTATION  INDUSTRIES. 

3.  DISTILLATION  OF  THE  FERMENTED  MASH,  OR  ALCOHOLIC 
LIQUID. — Upon  the  construction  of  apparatus  for  the  distilling  from  the 
fermented  mash  of  the  alcohol  which  it  contains  much  skill  and  ingenuity 
have  been  displayed,  and  some  of  the  later  forms  of  stills  and  rectifying 
apparatus  employed  in  large  distilleries  are  wonderfully  adapted  for  obtain- 
ing in  a  continuous  operation  the  purest  and  strongest  alcohol  from  the  crude 
fermentation  products.  We  may  distinguish  some  five  main  classes  of 
distilling  apparatus,  of  which  the  minor  varieties  are  too  numerous  to  be 
specially  enumerated.  These  classes  are :  first,  simple  stills  with  worm 
condenser  heated  by  direct  firing ;  second,  simple  stills  with  closed  "  wash- 
warmer"  ;  third,  stills  with  rectifying  "  wash-warmer"  ;  fourth,  stills  with 
"  wash- warmer,"  rectifying  and  dephlegmator  apparatus  for  intermittent 
working  ;  and,  fifth,  similar  forms  of  construction  for  continuous  working. 
The  first  and  simplest  of  these  classes  hardly  needs  any  special  description. 
The  stills  are  usually  of  copper,  flat-bottomed,  and  often  of  great  size,  es- 
pecially in  Irish  and  Scotch  whiskey  distilleries.  It  is  obvious  that  their 
use  involves  a  great  waste  of  fuel.  Therefore  one  of  the  earliest  devices  for 
economizing  the  heat  of  distillation  consisted  in  interposing  between  the  still 
and  the  refrigerating  apparatus  a  "  wash-warmer,"  or  vessel  filled  with  the 
liquid  ready  for  distillation.  Through  this  vessel  the  pipe  conveying  the  hot 
vapors  to  the  refrigerator  coil  passed,  and  the  vapors  partly  condensing  there 
heated  up  the  wash,  which  then  went  into  the  still  quite  hot.  Dorn's  appa- 
ratus, still  somewhat  used  in  smaller  establishments  in  Germany,  accom- 
plished the  same  thing,  and  effected  a  partial  rectification  of  the  distillate  by 
having  interposed  between  the  still  and  the  refrigerator  a  vessel  divided 
horizontally  into  two  compartments  by  a  diaphragm  of  copper.  The  upper 
and  larger  compartment  served  as  a  wash- warmer,  and  through  it  the  tube 
conveying  the  vapors  from  the  still  passed  into  the  lower  compartment,  where 
at  first  the  distillate  condensed.  As  the  wash  becomes  warmed  up  this  dis- 
tillate gives  oif  alcoholic  vapors,  which  then  pass  on  and  are  condensed  in 
the  worm,  while  the  watery  portion  is  allowed  to  flow  back  into  the  still  by 
a  side-connection.  It  is  obvious  that  this  rectifying  action  can  be  increased 
by  the  introduction  of  two  or  more  such  vessels  between  the  still  and  the 
final  condenser,  and  so  a  distillate  much  richer  in  alcohol  be  obtained. 

Another  principle  was  now  brought  into  play  in  effecting  a  fractional 
condensation,  that  of  dephlegmation,  or  chilling  the  vapor  coming  off  by 
contact  with  metallic  diaphragms  so  that  a  portion  of  it,  and  of  course  the 
most  watery,  is  condensed  and  separated  while  the  richly  alcoholic  vapor 
passes  on  into  the  rectifier  or  condenser.  Three  types  of  these  most  elab- 
orate apparatus  may  be  briefly  referred  to  :  the  Pistorius  apparatus,  used  in 
Germany  for  the  thick  potato-mashes  of  that  country,  which  is  intermittent, 
the  Coffey  still,  used  in  England  and  Scotland  for  the  thinner  worts  from 
grain,  and  the  column  apparatus,  first  introduced  by  Savalle  and  improved 
by  later  inventors,  which  is  used  in  France  for  distilling  wines  and  in  Ger- 
many to  follow  up  the  work  of  the  Pistorius  or  similar  apparatus.  Both 
the  Coffey  still  and  the  column  apparatus  are  continuous  in  action.  In  the 
Pistorius  apparatus,  two  boilers  and  a  wash-warmer  are  used  for  the  fresh 
mash,  and  are  connected  so  that  the  vapors  from  the  first  boiler  pass  into 
the  second  boiler,  heating  it  up  and  in  time  driving  vapor  from  it,  which 
then  passes  around  the  wash-warmer  and  goes  through  several  dephlegma- 
tors  placed  one  above  the  other.  In  these  the  watery  alcohol  is  continually 
being  condensed  and  running  back  to  the  second  boiler,  while  the  uncon- 


PROCESSES  OF  MANUFACTURE. 


221 


FIG.  65. 


222  FERMENTATION  INDUSTRIES. 

densed  vapor  which  escapes  from  the  top  dephlegmator  goes  finally  to  the 
refrigerating  apparatus.  The  Pistorius  apparatus  has  been  improved  upon 
by  Gall,  Schwartz,  and  Siemens.  The  Coifey  still,  illustrated  in  Fig.  65, 
consists  of  two  columns  placed  side  by  side,  made  of  wood  and  lined  with 
copper.  The  analyzer,  A,  is  divided  into  twelve  small  compartments  by 
four  horizontal  plates  of  copper,  a,  perforated  with  numerous  holes  and 
furnished  with  valves  opening  upwards.  Dropping-pipes,  6  6,  are  also 
attached  to  each  plate,  the  upper  end  of  the  pipe  being  an  inch  or  two 
above  the  plate  and  the  lower  end  dipping  into  a  shallow  pan,  c,  placed  on 
the  lower  plate.  The  second  column  or  rectifier,  jB,  receives  the  spirituous 
vapors  passing  from  the, column  A  through  the  pipe  #.  This  column  is  also 
divided  into  compartments  like  A,  but  there  are  fifteen  instead  of  twelve. 
The  ten  lower  diaphragms,  /,  are  pierced  with  small  holes  and  furnished 
with  drop-pipes,  while  the  upper  five  have  only  one  large  opening  sur- 
rounded by  a  ring  to  prevent  the  finished  spirit  from  returning.  Between 
each  of  these  compartments  passes  a  bend  of  a  long  zigzag  pipe,  n  nf,  one 
end  of  which  is  attached  to  the  pump  m,  whilst  the  other  end  discharges  the 
contents  of  the  pipe  into  the  top  of  the  column  A,  as  indicated  by  the  arrow. 
The  following  is  the  working  of  the  apparatus.  In  the  first  place,  the  fer- 
mented liquor  or  wash  is  pumped  up  by  the  pump  m  until  the  zigzag  pipe 
is  filled  and  the  wort  flows  over  the  compartments  a  a  a.  Steam  is  then 
admitted  into  the  compartments  of  the  analyzer  by  the  pipe  d  and  heats  the 
wash,  which  is  deprived  of  all  its  alcohol  by  the  time  it  reaches  the  bottom 
of  the  cylinder  and  flows  off  by  e/as  spent  wash.  The  strong  spirituous 
vapor  passes  through  g  to  the  rectifier,  and  at  last  through  the  worm  c  of 
the  refrigerator  into  the  receiver.  The  Coffey  still  is  recognized  as  the  best 
and  most  economical  device  for  preparing  a  highly-concentrated  spirit  in  a 
single  operation.  It  is  specially  adapted  for  preparing  from  grain-mashes 
what  is  called  "  silent  spirit,"  which  is  almost  entirely  destitute  of  flavor, 
and  of  a  strength  ranging  from  fifty-five  to  seventy  over  proof.  It  is 
not  so  well  adapted  for  the  distillation  of  malt  whiskey  as  fire-heated  stills, 
because  the  peculiar  flavor  of  the  whiskey  depends  upon  the  retention  by  the 
alcoholic  distillate  of  the  volatile  oils  produced  in  the  mash,  and  the  Coffey 
still  separates  the  alcohol  from  these  as  well  as  other  impurities.  The  forms 
of  apparatus  used  in  France  for  the  distillation  of  wines  are  illustrated  in 
that  of  Cellier-Blumenthal  as  improved  by  Derosne,  shown  in  Fig.  66. 
The  alcoholic  vapors  from  A  pass  into  J5,  and  thence  into  the  rectifying 
column  (7,  which  contains  a  series  of  perforated  metal  cups  over  which  wine 
from  the  wine-warmer,  E,  is  trickling.  The  vapors  thus  enriched  go 
through  the  upper  rectifying  column,  Z),  and  thence  to  the  wine-warmer,  E, 
which  serves  as  a  first  condenser,  and  then  to  the  cold  condenser,  F,  and  so 
to  the  collecting  vessel.  After  the  operation  is  well  under  way  the  supply 
of  wine  can  be  introduced  from  H  through  6r,  k,  and  E,  while  the  de-alco- 
holized liquid  can  be  run  off  from  the  lower  side  of  A. 

Another  form  of  still  very  largely  used  in  France  and  Belgium,  especially 
for  thin  mashes  like  molasses  and  beet-mash,  is  that  of  Savalle,  illustrated 
in  Fig.  67.  It  is  a  continuous-working  apparatus.  B  is  the  still  proper 
heated  by  steam-pipes,  A  is  the  rectifying  column,  C  is  for  catching  froth, 
D  is  a  warm  tube  condenser  and  E  the  cold  condenser.  The  elements  which 
form  the  condensing  and  rectifying  parts  of  the  column  A  are  shown  in 
Figs.  68  and  69.  The  vapors  rising  pass  through  the  holes  of  the  per- 
forated plates,  on  which  rests  a  layer  of  condensed  liquid  which  can  only 


PROCESSES   OF   MANUFACTURE. 


223 


drain  down  through  d  into  the  cup  c  placed  below  it.  From  these  cups  it 
overflows  upon  the  perforated  plate  and  is  again  drained  off  by  the  next 
connecting  tube,  d.  The  rising  vapors  are  therefore  washed  by  the  liquid 
upon  each  perforated  plate. 

FIG.  66. 


4.  RECTIFYING  AND  PURIFYING  OF  THE  DISTILLED  SPIRIT. — The 
products  from  the  preliminary  distillation  from  the  fermented  grain-  or 
potato-mash  are  not  at  first  sufficiently  strong,  but  must  be  strengthened  by 
rectifying.  In  England,  the  spirits  obtained  by  the  first  distillation  from 
grain-mash  are  generally  called  low  wines,  and  have  a  specific  gravity  of 


224 


FERMENTATION   INDUSTRIES. 


FIG.  67. 


FIG.  68. 


PROCESSES   OF   MANUFACTURE. 


225 


about  .975.  By  rectifying,  or  doubling,  a  crude  milky  spirit,  abounding  in 
oil,  at  first  comes  over,  followed  by  clear  spirit,  which  is  then  caught  sepa- 
rately. When  the  alcoholic  strength  of  the  distilled  liquid  has  considerably 
diminished,  the  remaining  weak  spirit  that  distils  over,  called  faints,  is 
caught  separately  and  mixed  with  the  low  wines  preparatory  to  another 


FIG.  70. 


distillation.  The  rectifying  is  most  rapidly  and  effectually  done  in  the  sev- 
eral forms  of  column  apparatus,  the  best  of  which  will  yield  a  very  pure 
alcohol  in  one  or  two  operations. 

An  improved  Savalle  rectifying  column  as  used  generally  in  French  and 
Belgian  distilleries  is  shown  in  Fig.  70.  It  consists  of  a  still,  A,  neated  by 
closed  steam-coils,  a  rectifying  column,  J5,  two  tubular  condensers,  Caud  Z>, 

15 


226  FERMENTATION   INDUSTRIES 

from  the  upper  of  which  any  condensed  vapors  flow  back  into  the  rectifying 
column  as  "  low  wines/7  while  the  lower  condenser  takes  the  more  volatile 
product  and  passes  it  on  as  high-grade  alcohol  to  the  receiving-vessel,  F. 

The  purifying  of  raw  spirit,  notably  that  from  grain  and  potatoes,  from 
what  is  called  fusel  oil  (propyl,  isobutyl,  and  amyl  alcohols)  is  also  a  matter 
of  great  importance  if  the  spirit  is  to  be  used  as  the  basis  of  any  manufac- 
tured liquors.  This  fusel  oil  sticks  persistently  to  the  alcoholic  distillates, 
and  alcohol  rectified  until  it  reaches  a  strength  of  ninety-five  or  ninety-six 
per  cent,  by  volume  contains  fusel  oil.  Some  acetaldehyde  also  remains  dis- 
solved in  the  alcohol,  giving  the  raw  spirit  a  bitter  taste.  Various  reme- 
dies have  been  proposed  of  a  chemical  nature,  such  as  a  treatment  of  the 
raw  spirit  with  oxidizing  agents  like  chromic  acid  and  ozone,  but  they  have 
accomplished  little  as  yet.  The  method  most  generally  in  use  is  to  dilute 
the  alcohol  with  water  until  it  is  about  fifty  per  cent,  strength,  by  which 
means  the  fusel  oil  separates  out  insoluble  in  the  dilute  spirit,  and  then  to 
filter  through  wood  charcoal.  This  process  seems  to  be  quite  successful  in 
removing  the  higher  alcohols.  The  wood  charcoal  can  be  revivified  by 
heating  to  redness  in  closed  retorts.  Another  method  which  is  now  being 
experimented  upon  on  a  large  scale,  known  as  the  Bang  and  Ruifin  process, 
is  to  shake  up  the  diluted  spirit  with  petroleum  oils,  which  have  the  power 
of  absorbing  the  fusel  oil  and  so  withdrawing  it  from  the  dilute  alcohol. 

5.  MANUFACTURE  OF  ALCOHOLIC  BEVERAGES  FROM  RECTIFIED 
SPIRIT. — Much  of  the  rectified  spirit,  from  whatever  source  derived,  is  used 
in  connection  with  the  manufacture  of  wines  for  fortifying  them  and  in 
arresting  fermentation  at  any  desired  stage.  The  so-called  "  silent  spirit'' 
made  in  England  by  the  use  of  the  Coffey  still  from  grain- wort  is  largely 
utilized  in  the  manufacture  of  factitious  brandies  and  wines,  and  the  same 
thing  applies  to  the  spirit  manufactured  in  France  from  beet-roots  and  beet- 
root molasses,  where  it  is  made  to  supply  the  deficiencies  in  the  wine  and 
Cognac  production.  The  composition  of  many  of  these  factitious  or  imita- 
tion liquors  will  be  spoken  of  in  the  next  section  in  enumerating  the  products 
of  this  industry. 

m.    Products. 

1.  RECTIFIED  AND  PROOF  SPIRIT. — "  Rectified  spirit  of  wine"  is  the 
name  given  to  the  most  concentrated  alcohol  producible  by  ordinary  distil- 
lation. The  British  Pharmacopoeia  describes  rectified  spirit  as  containing 
eighty-four  per  cent,  by  weight  of  real  alcohol  and  having  a  specific  gravity 
of  .838.  The  United  States  Pharmacopoeia  under  the  name  "alcohol" 
simply  calls  for  a  spirit  containing  ninety-one  per  cent,  of  real  alcohol  and 
having  a  specific  gravity  of  .820.  The  "  spirit"  of  the  German  Pharma- 
copoeia has  a  specific  gravity  of  .830  to  .834,  and  hence  corresponds  more 
nearly  to  the  British  "rectified  spirit." 

"  Proof  spirit"  is  a  term  in  constant  use  in  England  for  the  purposes  of 
excise,  and  its  strength  was  defined  by  act  of  Parliament  to  be  such  that  at 
51°  F.  (10°  C.)  thirteen  volumes  shall  weigh  the  same  as  twelve  volumes 
of  distilled  water.  The  "  proof  spirit"  so  made  will  have  a  specific  gravity 
of  .91984  at  15.5°  C.  (60°  F.)  and  contain,  according  to  Fownes,  49.24  per 
cent,  by  weight  of  alcohol  and  50.76  per  cent,  of  water.  Spirits  weaker 
than  proof  are  described  as  U.  P.  (under  proof),  stronger  than  proof  as 
O.  P.  (over  proof) ;  thus,  a  spirit  of  fifty  U.  P.  means  fifty  water  and  fifty 
proof  spirit,  while  fifty  O.  P.  means  that  the  alcohol  is  of  such  strength  that 


PRODUCTS.  227 

to  every  one  hundred  of  the  spirit  fifty  of  water  would  have  to  be  added  to 
reduce  it  to  proof  strength.  Tables  are  in  use  which  give  for  alcohol  of  a 
given  specific  gravity  at  15.5°  C.  (60°  F.)  the  corresponding  percentage  by 
weight,  percentage  by  volume,  and  percentage  of  proof  spirit  contained.  (See 
Wynter  Blyth,  Foods,  Composition  and  Analysis,  p.  371.) 

2.  ALCOHOLIC  BEVERAGES  MADE  BY  DIRECT  DISTILLATION  OF  THE 
FERMENTATION  PRODUCTS. — Arrack. — Any  alcoholic  liquor  is  called 
"arrack"  in  the  East,  but  arrack  proper  is  a  liquor  distilled  either  from 
toddy,  the  fermented  juice  of  the  cocoa-nut  palm,  or  from  malted  rice.  The 
arrack  from  Goa  and  Columbo  is  considered  the  best,  and  is  made  from 
toddy  alone.  This  latter  is  gotten  by  the  incision  of  the  palm,  and  is  col- 
lected in  pots  hung  to  the  tree  under  the  cuts.  It  is  then  fermented  and 
distilled.  In  preparing  the  other  variety,  as  carried  out  in  Batavia  and 
Jamaica,  the  rice  is  covered  with  water  and  allowed  to  germinate,  dried  at  a 
temperature  of  59°  F.,  which  arrests  germination,  and  then  a  wort  is  made 
from  the  malted  rice  in  the  same  manner  as  from  malted  grain,  which  is 
afterwards  distilled.  The  commonest  pariah  arrack  of  India  is  generally 
narcotic,  very  intoxicating,  and  unwholesome.  It  is  prepared  from  coarse 
jaggery  sugar,  spoilt  toddy,  refuse  rice,  etc.,  and  rendered  more  intoxicating 
by  the  addition  of  hemp  leaves,  poppy-heads,  juice  of  stramonium,  and  sim- 
ilar deleterious  substances. 

Brandy  in  its  purest  form  (Cognac)  is  the  direct  product  of  the  distilla- 
tion of  French  wines.  Its  peculiar  flavor  and  aroma  are  due  to  the  presence 
of  ethyl  pelargonate  (oananthic  ether).  The  better  qualities  of  Cognac  are 
distilled  from  white  wines,  the  inferior  varieties  from  the  dark-red  Spanish 
and  Portuguese  wines  or  from  the  marc  or  refuse  of  the  wine-press,  and 
called  eau  de  vie  de  mare.  A  great  deal  is  also  entirely  factitious,  being  mix- 
tures of  grain  spirit  and  water  to  which  different  coloring  and  aromatic 
substances  have  been  added.  When  first  distilled,  brandy,  like  other  spirit- 
uous liquors,  is  colorless,  when  it  is  known  as  white  brandy,  and  continues 
so  if  kept  in  glass-  or  stone- ware,  but  if  stored  in  oak  casks,  as  is  usually 
the  case,  it  gradually  acquires  a  yellowish  tint  from  the  wood,  and  it  is  then 
termed  pale  brandy.  The  still  deeper  color  which  it  frequently  possesses  is 
given  it  by  the  addition  of  caramel-color,  which  was  originally  designed  to 
simulate  the  appearance  of  an  old  brandy  long  stored  in  casks.  The  color- 
ing matter  is  also  sometimes  prepared  from  catechu  and  similar  astringent 
and  aromatic  substances. 

Numerous  recipes  for  factitious  brandies  are  furnished  for  the  use 
of  rectifiers  in  making  up  imitations  of  Cognac.  Two  such  recipes  are 
given  : 

No.  1. — Powdered  catechu,  100  grammes;  sassafras-wood,  10  grammes; 
balsam  of  tolu,  10  grammes  ;  vanilla,  5  grammes ;  essence  of  bitter  almonds, 
1  gramme  ;  well-flavored  alcohol  (at  85°),  1  litre. 

No.  2.— Malt  spirit  (17  U.  P.),  100  gallons;  nitrous  ether,  2  quarts; 
ground  cassia-buds,  4  ounces ;  bitter  almond  meal,  5  ounces ;  sliced  orris- 
root,  6  ounces;  cloves  in  powder,  1  ounce;  capsicum,  1J  ounces;  good 
vinegar,  3  gallons ;  brandy-coloring,  3  pints  ;  powdered  catechu,  2  pounds ; 
full-flavored  Jamaica  rum,  2  gallons.  Mix  in  an  empty  Cognac-cask  and 
macerate  for  a  fortnight,  with  occasional  stirring.  Produces  106  gallons  at 
21  or  22  U.  P. 

Kirschivasser  is  a  spirituous  liquor  obtained  in  the  Black  Forest  and  in 
Switzerland  by  the  distillation  of  cherries.  These  are  picked  free  from  the 


228  FERMENTATION  INDUSTRIES. 

stalks  and  only  the  sound  fruit  taken.  They  are  crushed  for  the  extraction 
of  the  juice,  and  a  portion  of  the  cherry-stones  are  then  separately  crushed 
so  as  to  bruise  the  kernels  and  returned  to  the  juice.  These  bruised  kernels 
impart  the  almond  flavor  to  the  product  and  give  to  it  a  small  quantity  of 
prussic  acid  (.15  gramme  per  litre  in  good  kirsch  and  more  in  inferior 
kinds).  After  fermentation  the  liquor  is  drawn  off  and  distilled  by  steam. 
The  kirsch  is  colorless,  of  agreeable  odor  and  flavor,  which  improves  by 
keeping,  and  equal  in  strength  to  the  strongest  spirit. 

Rum  is  a  spirit  obtained  in  the  West  Indies,  notably  in  Jamaica,  Mar- 
tinique, and  Guadeloupe,  from  the  molasses  of  the  sugar-cane  by  fermenta- 
tion and  distillation.  The  process  of  fermentation  of  the  molasses  as  carried 
out  in  Jamaica  has  already  been  described.  When  new,  rum  is  white  and 
transparent,  and  has  when  freshly  distilled  an  unpleasant  odor,  due  to  oils 
contained.  These  are  got  rid  of  by  treatment  with  charcoal  and  lime.  It 
owes  its  characteristic  flavor  to  butyric  ether,  which  compound  is  also  pre- 
pared artificially  on  a  large  scale,  and  as  rum  essence  is  used  with  "  silent 
spirit"  to  make  a  factitious  rum.  Rum  is  always  colored  artificially  with 
caramel-color. 

Whiskey  is  the  spirit  obtained  from  the  fermented  wort  of  corn,  rye,  and 
barley,  either  raw  or  malted.  In  Scotland  and  Ireland,  malted  barley,  pure 
or  mixed  with  other  grain,  is  chiefly  used  ;  in  the  preparation  of  the  Bour- 
bon whiskey  of  Kentucky  partially-malted  corn  and  rye  are  taken,  while 
for  the  Monongahela  whiskey  of  Western  Pennsylvania  only  rye  (with  ten 
per  cent,  of  malt)  is  used. 

The  difference  between  the  Irish  and  the  Scotch  whiskeys  lies  mainly  in 
the  fact  that  the  former  is  distilled  in  the  common  or  so-called  pot-stills, 
which  brings  over  together  with  the  spirit  a  variety  of  flavoring  and  other 
ingredients  from  the  grain,  while  in  Scotland  the  Coffey  still  is  used,  the 
product  of  which  is  a  spirit  deprived  of  essential  oils.  The  Irish  "  poteen" 
whiskey  has  a  smoky  flavor,  due  to  the  use  of  peat  fires  in  preparing  the 
malt.  This  flavor  is  imitated  by  the  addition  of  one  or  two  drops  of  crea- 
sote  to  the  gallon  of  spirits. 

3.  ALCOHOLIC  BEVERAGES  MADE  FROM  GRAIN  SPIRIT  BY  DISTILLA- 
TION UNDER  SPECIAL  CONDITIONS. — Gin  is  common  grain  spirit  distilled 
and  aromatized  with  juniper-berries,  either  when  the  "low  wines"  are  con- 
centrated or  later,  using  full-strength  spirit.     The  proportion  employed  is 
variable,  depending  upon  the  nature  of  the  spirit ;  usually  one  kilogramme 
of  berries  is  enough  to  flavor  one  hectolitre  of  raw  grain  spirit.     The  finest 
gin,  known  as  "  Hollands,"  is  made  in  the  distilleries  of  Schiedam,  whence 
also  the  name  "  Schiedam  Schnapps."     Strassburg  turpentine,  oil  of  fennel, 
coriander  and  cardamom  seeds  are  frequently  substituted  either  wholly  or  in 
part  for  the  juniper-berries,  particularly  in  the  English-made  gin.     The 
quality  and  healthfulness  of  the  gin  depends  largely  upon  the  purity  of  the 
spirit  used  in  the  distillation,  whether  raw  or  rectified. 

It  is  obvious  that  many  factitious  brandies  belong  also  in  this  class,  being 
made  by  distillation  of  mixtures  of- which  grain  spirit  is  the  basis  and  not 
by  distillation  of  wine.  These  have  already  been  described. 

4.  LIQUEURS  AND  CORDIALS. — Liqueurs  is  the  name  now  given  to  such 
spirituous  drinks  as  are  obtained  by  mixing  various  aromatic  substances, 
such  as  anise,  absinthe,  essence  of  orange-peel,  etc.,  with  brandy  or  alcohol. 
Most  are  obtained  by  steeping  in  pure  brandy  or  spirit  different  fruits  or 
aromatic  herbs  and  submitting  the  resulting  liquid  to  distillation.      They 


PRODUCTS. 


229 


are  then  colored,  and"  are  usually  sweetened  with  sugar.  The  best  known 
of  them,  absinthe,  contains  a  characteristic  ingredient,  oil  of  wormwood,  to 
which  its  deleterious  effects  on  the  nervous  system  are  supposed  to  be  due. 
At  the  same  time  the  amount  of  total  essential  oils  held  dissolved  in  the 
strongly  alcoholic  liquid  are  such  that  when  diluted  with  water  the  solution 
becomes  milky  and  turbid. 

Among  the  liqueurs  may  be  enumerated  Absinthe  (consumed  chiefly  in 
Paris),  Anisette  (made  in  the  south  of  France),  Chartreuse  (made  by  the  monks 
of  the  Grande  Chartreuse  Monastery  near  Grenoble),  Cwagoa  (originally 
made  in  Holland  of  Cura9oa  oranges),  Maraschino  (made  in  Italy  of  Dal- 
matian cherries),  Ratafia  (made  in  France  from  a  great  variety  of  fruits), 
and  Usquebaugh  (a  strong  cordial  made  in  Ireland.  It  furnishes  the  name 
from  which  the  word  whiskey  is  derived). 

The  composition  of  the  several  alcoholic  liquors  enumerated  cannot  be 
given  in  great  detail,  as  their  differences  depend  so  largely  upon  the  flavor- 
ing and  aromatic  ethers  and  essential  oils,  which  are  present  in  very  minute 
quantities.  Their  general  differences  in  alcoholic  strength  and  the  extract 
and  ash  of  several  are,  however,  given  on  the  authority  of  Konig :  * 


Alcohol 
by 
volume. 

Alcohol 
by 
weight. 

Alcohol 
by 
volume. 

Alcohol 
by 
weight. 

Russian  Dobry  wutky 

62.0 

54.2 

Gin  

47.8 

40.3 

Scotch  whiskey  .  .  . 
Irish  whiskey 

50.3 
49  9 

42.8 
42  3 

Ordinary  German  schnapps 
Rum                              .       . 

45.0 

49.7 

37.9 
42.2 

English  whiskey  .  . 
American  whiskey  .  . 

49.4 
60.0 

41.9 
52.2 

French  Cognac  brandy  .    . 

55.0 

47.3 

And  in  one  hundred  cubic  centimetres  of  the  following : 


Specific 
gravity. 

Alcohol  by 
volume. 

Alcohol  by 
weight. 

Extract 

Ash. 

Arrack     ...       

0.9158 

60.5 

52.7 

0.082 

0024 

0.8987 

69.5 

61.7 

0.645 

0009 

0.9378 

51.4 

34.7 

1.260 

0.059 

The  composition  of  some  of  the  well-known  liqueurs  is  also  given  on 
the  same  authority :  f 


Specific 
gravity. 

Alcohol 
by 
volume. 

Alcohol 
by 

weight. 

Extract. 

Cane- 
sugar. 

Other  ex- 
tractions. 

Ash. 

Absinthe  
Bonekamp  of  Maag  bitters 
Benedictine  bitters  .  .  . 
Ginger  

0.9116 
0.9426 
1.0709 
1.0481 

58.93 
50.0 
52.0 
47  5 

42.5 
444 

402 

0.1  8J 
2.05 
36.00 
27  79 

32.57 
25  92 

0.32 

3.43 
1  87 

0.106 
0.043 
0.141 

Creme  de  men  the  .... 
Anisette  of  Bordeaux  .  . 
Cura9oa 

.0447 

.0847 
1  0300 

48.0 
42.0 
55  0 

407 
35.2 
47  3 

28.28 
34.82 
28  60 

27.63 
3444 
28  50 

0.65 
0.3<* 
0  10 

0.068 
0.040 
0040 

Kummel  liqueur  .... 
Peppermint  liqueur  .  .  . 
Swedish  punch  

.0830 
.1429 
1.1030 

33^9 
34.5 
26  3 

28.0 
28.6 
21  6 

32.02 

48.25 
36  61 

31  18 
47.35 

0.84 
0.90 

0058 
0.068 

*  Konig,  Nab  rungs-  und  Genussmittel,  vol.  ii.  p.  469. 
f  Ibid.,  p.  470.  |  Oil  of  wormwood. 


230 


FERMENTATION   INDUSTRIES. 


5.  Srt>E-PRODUCTS. — The  distiller's  residues  (Schlempe,  vinasse)  form  a 
side-product  of  considerable  value  as  a  cattle  food  because  of  its  composi- 
tion. It  is  especially  rich  in  protein  matter,  fat,  and  non-nitrogenous  ex- 
tractive, or  carbohydrates.  The  residues  from  the  beet-  and  cane-molasses 
distillation,  moreover,  yield  an  ash  very  rich  in  potash  salts,  so  that  they 
constitute,  especially  in  France,  a  very  important  source  of  potashes.  The 
composition  of  several  of  these  distillery  residues  are  given  in  the  moist 
state  on  the  authority  of*  Konig  :  * 


Nitro- 

Non -nitro- 

Water. 

Fat. 

genous 

genous 

Cellulose. 

Ash. 

matter. 

extract. 

Rye-mash  residues  (ten 

analyses) 

9348 

022 

1  40 

405 

052 

0.33 

Potato-mash       residues 

(six  analyses)  .... 

95.10 

0.17 

1.17 

2.17 

0.92 

0.47 

Molasses  residues    .    .    . 

91.86 

•    • 

2.04 

4.56 

1.54 

Two  complete  analyses  of  distillery  residues  dried  by  centrifugating 
and  heating  in  kilns  are  given  on  the  authority  of  Rosenbaum  :f 


Maize. 

Water 11.62 

Ash 6.50 

Crude  proteid  matter 21.44 

Crude  fibre 10.54 

Non-nitrogenous  extractives 38.96 

Crude  fat 11.44 

100.00 


Potatoes. 

7.83 
16.40 
23.08 

8.60 
40.54 

3.55 

100.00 


Of  these  constituents  the  following  were  assimilable  as  food : 

Albuminoids 17.20  18.50 

Carbohydrates 37.40  39.40 

Fat 9.10  2.85 

TV.  Analytical  Tests  and  Methods. 

The  most  important  determination  in  this  class  of  beverages  is  the 
alcoholic  strength.  In  the  case  of  rectified  or  proof  spirit,  a  simple  specific 
gravity  determination  is  all  that  is  necessary,  and  then  the  percentage 
strength  can  be  found  from  the  alcohol  tables  that  have  been  prepared. 
The  determination  should  be  made  at  15.5°  C.  (60°  F.),  or  if  at  another 
temperature,  a  correction  in  the  reading  must  be  made.  By  multiplying 
the  number  of  degrees  above  or  below  15°  by  .4  and  adding  the  product  to 
the  percentage  given  by  the  table  when  the  temperature  is  lower  than  15°, 
or  deducting  it  when  the  temperature  is  above,  we  get  a  correct  result.  In 
freshly-distilled  and  colorless  whiskeys  and  brandies,  in  which  the  amount 
of  extract  is  trifling,  the  alcoholic  percentage  can  also  be  determined  with 
sufficient  accuracy  by  the  specific  gravity  method.  In  such  liquors  as  con- 
tain more  extractive  matter,  like  rum  and  the  liqueurs  and  cordials,  the 


*  Konig,  Nahrungs-  und  Genussmittel,  vol.  ii.  p.  468. 
f  Jahresber.  der  Chem.  Technol.,  1887,  p.  1058. 


ANALYTICAL  TESTS   AND   METHODS.  231 

alcohol  must  first  be  distilled  off,  and  then  made  up  to  original  volume  with 
distilled  water,  as  described  on  p.  212. 

A  process  of  estimating  the  alcohol  by  oxidizing  it  into  acetic  acid  and 
determining  this  by  volumetric  soda  solution  has  also  been  recommended 
by  Dupre,  but  it  can  only  be  applied  to  a  pure  alcoholic  distillate,  and  has 
no  advantage  over  the  specific  gravity  determination  made  on  the  same  dis- 
tillate. It  is  obvious  that  the  Geissler  vaporimeter  and  the  several  forms 
of  ebullioscope  (see  p.  212)  can  be  applied  with  rectified  or  proof  spirit, 
but,  as  said  before,  they  are  not  capable  of  the  greatest  accuracy. 

The  detection  and  determination  of  fusel  oil,  which  is  a  persistent  im- 
purity in  potato  and  grain  spirit,  is  one  of  the  most  important  tests  to  be 
made.  To  detect  it,  the  greater  part  of  the  alcohol  is  distilled  off  at  as 
low  a  temperature  as  possible,  the  residual  liquid  mixed  with  an  equal 
amount  of  ether  and  well  shaken.  The  ethereal  layer  is  then  separated 
and  allowed  to  evaporate  spontaneously,  when  amyl  alcohol,  if  present,  will 
be  recognized  in  the  residue  by  its  smell  and  chemical  characters.  Petro- 
leum-ether may  be  advantageously  substituted  for  the  ether  in  this  test. 

Marquardt  dilutes  forty  cubic  centimetres  of  the  spirit  with  sufficient 
water  to  bring  the  density  to  about  .980  and  then  agitates  the  liquid  with 
fifteen  cubic  centimetres  of  pure  chloroform.  The  chloroform  is  allowed 
to  settle,  separated,  and,  after  shaking  with  an  equal  measure  of  water,  is 
allowed  to  evaporate  spontaneously.  The  residue  is  treated  with  a  little 
water  and  one  or  two  drops  of  sulphuric  acid,  and  sufficient  solution  of 
potassium  permanganate  is  then  added  to  cause  the  mixture  to  remain  red 
after  standing  for  twenty-four  hours  in  a  closed  tube.  Shortly  after  adding 
the  permanganate  the  odor  of  valeric  aldehyde  will  be  observable,  but  after 
standing  only  the  odor  of  valeric  acid  is  distinguishable.  This  can  be 
recognized  even  when  the  original  residue  is  almost  odorless  and  the  smell 
is  not  masked  by  the  presence  of  essential  oils,  etc.  Marquardt  has  devised 
a  more  elaborate  modification  of  the  test  to  serve  for  the  quantitative  deter- 
mination of  the  fusel  oil  present.  For  the  detailed  description  the  reader  is 
referred  to  Allen,  3d  ed.,  vol.  i.  p.  154. 

Caramel  (burnt  sugar)  is  used  for  coloring  and  flavoring  spirits,  and  is 
left  as  a  brown  residue  on  evaporating  the  spirit  on  the  water-bath.  This 
residue  is  distinguished  by  its  bitter  taste,  and  if  further  heated  it  carbonizes 
and  smells  of  burnt  sugar. 

Tannin  is  often  present  in  brandy  and  whiskey,  being  chiefly  extracted 
from  the  casks  used  in  storing.  Sometimes,  as  in  factitious  brandies,  it  is 
purposely  added  in  the  form  of  tincture  of  oak-bark.  It  may  be  detected 
by  the  darkening  produced  on  adding  ferric  chloride  to  the  spirit,  and  any 
reaction  thus  obtained  may  be  confirmed  by  boiling  off  the  alcohol  from 
another  portion  of  the  spirit  and  adding  solution  of  gelatine  to  the  residual 
liquid,  when  a  precipitate  will  be  produced  if  tannin  be  present. 

E.  BREAD-MAKING. 

Bread-making  as  ordinarily  conducted  is  to  be  classed  as  one  of  the  fer- 
mentation industries,  as  the  swelling  of  the  dough  which  must  precede  the 
baking  is  generally  accomplished  by  the  aid  of  the  alcoholic  fermentation 
brought  about  by  the  addition  of  "  leaven"  or  yeast.  For  every  kilogramme 
of  bread,  on  the  average,  2.5  grammes  of  alcohol  and  2.7  grammes  of  car- 
bon dioxide  gas  are  produced.  Both  are  lost  in  the  baking,  but  the  carbon 


232  FERMENTATION    INDUSTRIES. 

dioxide  gas  when  first  generated  is  caught  in  the  thick  and  viscid  dough  and 
causes  it  to  swell  up  and  become  spongy  in  structure.  This  not  only  gives 
to  the  bread  when  baked  a  porous  and  cellular  structure,  but  allows  the 
chemical  changes  to  take  place  throughout  its  entire  substance,  whereby  it  is 
made  more  readily  digestible. 

As  the  only  effective  result  of  the  alcoholic  fermentation  is  performed 
by  the  carbon  dioxide,  of  course  the  addition  of  chemical  mixtures  liber- 
ating carbon  dioxide  gas  in  the  dough  may  be  made  to  obviate  the  necessity 
of  using  leaven  or  yeast,  and  similarly  aerated  breads  may  be  made  by  simply 
forcing  carbon  dioxide  under  pressure  into  the  dough. 

A  few  varieties  of  bread  are  made  from  dough,  baked  without  any  aera- 
tion either  natural  or  artificial,  such  as  hard  crackers,  the  unleavened  bread 
of  the  Jews,  the  Scotch  oat-cake,  and  the  corn-cake  of  the  Southern  States. 
These  exceptions  are  of  relatively  minor  importance,  and  by  far  the  largest 
amount  of  bread  is  prepared  by  the  aid  of  a  fermentation  process. 


I.  Raw  Materials. 

1.  FLOUR. — This  may  be  from  either  wheat,  rye,  barley,  oats,  maize,  or 
Indian  corn,  and  rice,  although  wheat  flour  is  used  in  far  the  largest  amount. 

The  average  composition  of  the  several  cereals  has  already  been  given. 
(See  page  169.)  Wheat  flour  contains  the  following  substances  :  starch,  dex- 
trine, cellulose,  sugar,  albumen,  gliadin,  or  gluten,  mucin,  fibrin,  cerealin,  fat, 
mineral  matters,  and  water.  The  first  four  are  carbohydrates,  or  non-nitro- 
genous substances,  and  they  form  nearly  three-fourths  of  the  entire  weight  of 
the  flour.  The  nitrogenous  matter  consists  of  at  least  five  principles,  three 
of  which,  gluten  (or  gliadin),  mucin  (or  mucedin),  and  fibrin,  constitute  the 
bulk  of  the  material  known  as  crude  gluten,  which  is  the  substance  left 
when  flour  is  kneaded  with  water  and  afterwards  washed  to  remove  the 
starch  and  any  soluble  substance.  The  remaining  two  nitrogenous  princi- 
ples, albumen  and  cerealin,  are  soluble  in  water,  and  are  carried  away  with 
the  starch  in  the  process  of  washing.  Crude  gluten  possesses  a  peculiar  ad- 
hesiveness, arising  from  the  presence  of  gliadin,  which  is  a  highly  tenacious 
body,  and  which  is  not  present  in  the  same  form  in  other  cereal  flours.  It 
is  this  adhesive  property  which  gliadin  imparts  to  gluten  that  renders 
wheaten  flour  so  well  adapted  for  bread-making  purposes. 

The  vegetable  albumen  mentioned  above  -as  soluble  in  cold  water  is  ac- 
companied also  by  small  amounts  of  legumin,  or  vegetable  casein,  which  is 
also  soluble  in  water.  The  cerealin  is  a  soluble  nitrogenized  ferment  occur- 
ring especially  in  the  husk  or  bran  of  wheat  and  other  cereals.  It  has  a 
powerful  fermentative  action  on  starch,  rapidly  converting  it  into  dextrine 
and  other  soluble  bodies.  The  presence  of  cerealin  in  bran  renders  "  whole 
meal"  unsuitable  for  making  bread  by  fermentation  with  yeast,  though  it 
can  be  used  with  baking-powders,  and  "  aerated  bread"  can  be  made  from  it. 
The  cerealin  acts  like  malt  extract,  causing  a  too  rapid  conversion  of  the 
starch  into  dextrine  and  sugar,  and  hence,  although  the  bran  is  rich  in  nitro- 
genous food  constituents  and  salts  like  phosphates,  it  is  ordinarily  separated 
from  the  flour.  The  difference  in  the  composition  of  the  several  parts  of 
the  wheat-grain  is  seen  in  the  following  table  given  by  Church  :* 

*  A.  H.  Church,  Foods,  etc.,  South  Kensington  Hand-book,  pp.  63  and  64. 


EAW   MATERIALS. 


233 


FINE  WHITE  FLOUR. 

COARSE  WHEVT  BRAN. 

In  100 
parts. 

In  1  pound. 

In  100 
parts. 

In  1  pound. 

Water     
Fibrin,  etc  

13.0 
10.5 
74.3 
0.8 
0.7 
0.7 

2  ounces    35  grains. 
1      "       297 
11      "       388       ' 
0      "         57 
0      «         49 
0      '•         49 

14.0 
15.0 
44.0 
4.0 
17.0 
6.0 

2  ounces  10")  grains. 
2               175 
7           ~   17 
0              280       < 
2               316       ' 
0               422 

Starch  etc 

Fat 

Cellulose 

Mineral  matter  

Of  course,  milling  processes  have  to  be  specially  adapted  to  the  separa- 
tion of  these  quite  different  parts  of  the  wheat-grain,  the  white  flour  free 
from  bran  being  sought.  By  the  old-fashioned  "  low-milling"  process,  or 
grinding  between  stones  placed  very  close  together  and  bolting,  it  was  impos- 
sible to  obtain  a  flour  entirely  free  from  contamination.  The  advance  to 
"  high-milling"  with  stones  far  apart,  allowing  the  middlings  which  were 
produced  to  be  purified  before  grinding  to  flour,  was  a  step  which  made  it 
possible  to  make  from  winter  wheat  an  excellent  and  pure  flour.  When, 
however,  spring  wheat  with  its  hard  and  brittle  outer  coats  became  important 
commercially,  it  was  necessary  to  resort  to  the  roller  methods  of  milling, 
which,  in  conjunction  with  peculiar  purifying  machinery,  would  furnish  a 
flour  free  from  all  undesirable  impurities.  This  latter  process  has  now 
almost  universally  replaced  the  other  in  the  newer  mills. 

While  most  of  the  other  cereals  before  mentioned  may  be  found  occa- 
sionally in  admixture  with  wheat  flour,  very  few  are  used  alone  as  substi- 
tutes for  it.  Rye  flour  is  probably  the  only  one.  It  makes  a  dark-colored, 
heavy  and  sourish  bread,  which,  however,  keeps  moist  a  long  time.  It  is 
much  used  in  Germany  and  Northern  Europe  under  the  name  of  "  black 
bread."  A  more  palatable  bread  may  be  made  from  a  mixture  of  two  parts 
wheat  flour  and  one  part  rye  flour.  This  latter  flour  contains  a  slightly 
larger  amount  of  fat  and  of  mineral  matter  than  wheat  flour.  It  is  never 
so  white  as  wheat  flour  and  the  gluten  has  very  little  adhesive  character. 
Ritthausen  states  that  the  gluten  of  rye  flour  consists  chiefly  of  mucin 
(mucedin)  and  vegetable  casein,  and  that  gliadin  is  absent  entirely. 

2.  YEAST,  OR  FERMENT. — The  yeast  is  at  present  almost  always  added, 
either  as  brewer's  yeast  or  compressed  yeast.  In  former  times  (and  to  a 
considerable  extent  still  in  France)  wheat  bread  was  made  by  the  use  of 
leaven  j  which  consists  of  a  portion  of  dough  left  over  from  a  previous  baking, 
charged  with  the  ferment  and  in  part  changed  by  its  action.  This  leaven 
is  originally  gotten  by  allowing  flour  and  water  to  start  into  spontaneous 
fermentation,  the  nitrogenous  matters  becoming  soluble  and  attacking  the 
starch  and  sugar.  The  leaven  tends,  however,  to  continue  its  decomposition 
and  to  pass  from  the  alcoholic  into  the  lactic  fermentation.  Hence,  if  the 
leaven  is  in  the  proper  stage  of  decomposition,  it  will  induce  the  alcoholic 
fermentation  and  generate  carbon  dioxide  gas,  raising  the  dough ;  if  it  be, 
however,  in  a  more  advanced  state  of  decomposition,  lactic  fermentation 
will  be  induced  and  the  bread  will  not  raise,  but  become  heavy  and  sour. 
In  domestic  practice,  to  avoid  this  latter  result,  salseratus  (bicarbonate  of 
potash  or  soda)  is  added  to  the  dough.  This  neutralizes  the  lactic  acid  as 
fast  as  formed,  and  at  the  same  time  liberates  carbon  dioxide  gas  to  inflate 


234  FERMENTATION   INDUSTRIES. 

the  dough.     An  excess  of  this  salt,  however,  makes  the  bread  alkaline  to 
the  taste  and  yellow  in  color. 

The  black  rye  bread  of  Germany  is  also  made  with  the  aid  of  a  leaven 
known  as  "  sour  dough."  In  this  both  the  alcoholic  and  the  lactic  fermen- 
tations are  in  progress,  the  latter,  however,  preponderating.  Four  parts  of 
such  sour  dough  are  used  for  one  hundred  parts  of  flour. 

The  brewer's  yeast  for  bread-raising  purposes  must  be  a  fresh  and  vig- 
orous yeast-growth,  as  its  value  here  depends  largely  upon  the  energy  of 
the  fermentation  set  up  and  the  amount  of  gas  given  off.  Its  appearance 
and  characters  have  been  described  before.  (See  p.  185.)  Unless  of  the  best 
quality,  compressed  yeast  is  to  be  preferred  because  of  its  reliability.  The 
manufacture  of  this  latter  is  carried  out  chiefly  in  connection  with  the  spirit 
distilleries.  At  the  time  when  the  fermentation  is  most  energetic,  the  yeast  is 
skimmed  off  the  surface  and  conveyed  by  wooden  shoots  to  steam  sieves,  by 
which  the  husks  are  eliminated,  the  strained  liquid  passing  on  to  the  settling 
cisterns.  When  settled  the  surface  liquid  is  drained  off  and  sent  for  distil- 
ling purposes,  and  the  yeasty  sediment  mixed  with  starch  and  put  into  the 
filter-presses,  which  squeeze  out  all  the  liquid,  leaving  a  dough-like  paste, 
which,  when  sufficiently  dry,  is  packed  into  bags  and  packets  and  is  ready 
for  distribution.  Yeast  from  its  peculiar  slimy  nature  cannot  be  pressed 
well,  hence  the  addition  of  starch,  which  permits  the  removal  of  more  of 
the  liquid  from  the  yeast.  Absolutely  pure  yeasts  do  not  keep  so  well  as 
the  same  yeasts  with  an  addition  of  from  five  to  ten  per  cent,  of  starch. 
In  high-class  yeasts  the  quantity  added  is  about  five  or  six  per  cent. ;  it  is 
often  added  in  quantity  beyond  this  as  an  adulterant.  A  good  sample  of 
compressed  yeast  has  the  following  characteristics :  It  should  be  only  very 
slightly  moist,  not  sloppy  to  the  touch ;  the  color  should  be  a  creamy  white ; 
when  broken  it  should  show  a  fine  fracture ;  when  placed  upon  the  tongue 
it  should  melt  readily  in  the  mouth ;  it  should  have  an  odor  of  apples,  not 
like  that  of  cheese ;  neither  should  it  have  an  acid  taste  or  odor.  Any 
cheesy  odor  shows  that  the  yeast  is  stale  and  that  incipient  decomposition 
has  set  in. 

3.  BAKING-POWDERS. — To  obviate  the  necessity  of  using  yeast  and 
waiting  until  the  dough  should  rise  sufficiently  under  the  influence  of  fer- 
mentation, it  was  early  sought  to  supply  the  necessary  carbon  dioxide  to 
the  dough  by  chemical  reactions.  The  earliest  proposal  was  that  of  Liebig 
to  use  sodium  bicarbonate  and  hydrochloric  acid,  which  should  evolve  car- 
bon dioxide  and  leave  sodium  chloride  (common  salt)  in  the  dough.  Next 
was  proposed  sodium  bicarbonate  and  tartar ic  acid,  or  acid  potassium  tar- 
trate  (cream  of  tartar).  More  generally  satisfactory  than  either  of  these 
was  acid  calcium  phosphate  (either  alone  or  with  acid  magnesium  phos- 
phate), which  with  bicarbonate  of  soda  formed  Horsford's  baking-powder. 
More  objectionable  was  the  introduction  of  alum  with  the  sodium  bicarbon- 
ate. Most  of  these  baking-powder  mixtures,  then,  have  starch  or  flour 
added  as  "  filling,"  and  in  amount  varying  from  twenty  to  sixty  per  cent. 
Sesquicarbonate  of  ammonia  is  also  used  in  many  of  the  mixtures,  re- 
placing part  of  the  bicarbonate  of  soda.  Self-raising  flours  have  these 
baking-powders  already  added  to  the  flour  in  such  proportions  as  will 
insure  a  spongy  dough  upon  the  simple  addition  of  water  and  kneading 
into  loaves. 


PROCESSES   OF   MANUFACTURE.  235 


IE.  Processes  of  Manufacture. 

1.  THE  MIXING  OF    THE  DOUGH  AND    ITS   FERMENTATION. — The 
mixing  of  the  flour  with  water  is  not  only  for  the  purpose  of  bringing  into 
solution  the  dextrine,  the  sugar,  and  the  soluble  albuminoids,  and  of  allowing 
these  latter  as  peptones  to  act  upon  the  insoluble  constituents  of_the  flour, 
such  as  the  gluten,  but  also  to  penetrate  and  soften  the  starchy  material. 

The  yeast  may  be  added  directly  along  with  the  water  to  some  of  the 
flour  to  prepare  a  "  sponge,"  from  which  the  whole  batch  of  dough  is  after- 
wards made,  or  a  "  ferment"  may  be  made  from  the  yeast  with  potatoes, 
which  then  is  used  to  prepare  the  "  sponge."  In  the  latter  case,  potatoes 
are  boiled  and  mashed  with  water  into  a  moderately  thin  liquor,  to  which 
the  yeast  is  added,  and  the  fermentation  is  allowed  to  proceed  for  some  time. 
In  either  case,  whether  the  yeast  is  used  direct  or  a  potato  ferment  is  first 
made,  it  is  worked  up  with  a  portion  of  the  flour  into  a  slack  dough,  which 
constitutes  the  sponge,  and  is  set  to  rise  in  a  warm  place.  When  the  sponge 
has  risen  sufficiently  the  remainder  of  the  flour  is  worked  in  with  sufficient 
water  to  which  some  salt  has  been  added,  and  the  dough  is  made,  kneaded, 
allowed  to  stand  again  to  rise,  and  then  prepared  for  baking. 

The  use  of  potato  ferment  is  based  upon  the  belief  that  the  yeast-cells 
are  strengthened  by  the  soluble  nitrogenous  matter  of  the  potato,  which  acts 
as  a  yeast  stimulant  and  enables  a  smaller  quantity  of  yeast  to  hydrolyze  a 
larger  amount  of  starch.  The  yeast-cells  then  act  very  rapidly  upon  the 
glucose  so  produced  and  develop  the  alcoholic  fermentation.  The  albumi- 
noids of  the  flour  are  also  softened  and  partially  peptonized,  and  these  changed 
albuminoids  in  turn  assist  in  the  hydrolysis  of  the  starch. 

2.  BAKING. — For  baking,  the  oven  should  have  a  temperature  of  400° 
to  450°  F.  (200°  to  230°  C.).     Before  putting  the  loaves  in,  they  are  often 
wetted  on  the  surface  so  as  to  assist  in  the  prompt  formation  of  a  crust  that 
shall  prevent  the  dough  from  expanding  too  rapidly.     The  heat  expands  the 
gases  throughout  the  loaf  and  so  swells  it  and  vaporizes  a  portion  of  the 
moisture.     The  action  of  the  heat  and  steam  soon  converts  the  starch  on  the 
surface  of  the  loaf  into  dextrine  and  maltose,  and  these  at  the  high  tempera- 
ture are  slightly  caramelized,  thus  giving  the  crust  its  brownish  color.     At 
the  temperature  of  the  interior  of  the  loaf  (212°  F.  or  slightly  above)  the 
starch-cells  will  have  burst,  the  coagulable  albuminoids  will  have  been  coagu- 
lated, and  their  diastatic  power  entirely  destroyed. 

Steam  is  often  injected  into  the  oven  during  the  baking.  The  effect  is 
to  produce  a  glazed  surface  on  the  outside  of  the  crust.  It  not  only  dex- 
trinizes  and  glazes  the  crust,  but  keeps  the  interior  of  the  loaf  moist  by  pre- 
venting too  rapid  evaporation.  Of  course,  in  perfectly  tight  ovens  the  steam 
resulting  from  the  evaporation  of  the  moisture  of  the  bread  is  kept  in,  and 
soon  acts  in  the  same  manner  though  in  a  lesser  degree. 

One  hundred  kilogrammes  of  flour  will  yield,  according  to  its  quality, 
from  one  hundred  and  twenty-five  to  one  hundred  and  thirty-five  kilos,  of 
bread. 

3.  USE  OF  CHEMICALS  FOREIGN  TO  THE  BREAD. — Both  alum  and 
sulphate  of  copper  (and  notably  the  former)  have  been  used  in  baking  bread 
from  inferior  or  unsound  flours  in  order  to  improve  the  appearance  of  the 
bread.     This  they  do  by  preventing  or  lessening  the  breaking  up  of  the 
gluten  and  starch  during  fermentation,  and  so  cause  a  loaf  made  from  a  bad 


236 


FERMENTATION   INDUSTRIES. 


flour  to  be  larger,  less  sodden,  and  whiter,  giving  it  the  appearance  of  having 
been  made  from  better  flour.  As  these  chemicals  are  injurious  to  health, 
and  as  their  sole  purpose  is  to  allow  of  deception  as  to  the  character  of  the 
flour  used  in  bread-baking,  they  ought  to  be  prohibited  by  law. 

Liebig  suggested  the  use  of  lime-water  as  a  means  of  retarding  too  rapid 
decomposition  of  the  starch  during  the  fermentation  of  bread-making.  The 
bread  made  with  the  proper  amount  of  lime-water  is  said  by  Jago*  to  be 
more  spongy  in  texture,  pleasant  in  taste,  and  quite  free  from  sourness.  In 
the  bread  the  lime  exists  as  calcium  carbonate,  but  in  such  quantities  as  to 
be  perfectly  harmless.  The  use  of  lime-water  in  bread-making  is  said  to  be 
practised  extensively  by  Glasgow  bakers. 

m.  Products. 

1.  BREAD. — The  nature  of  the  change  which  the  flour  undergoes  in  the 
bread-baking  process  has  already  been  indicated  in  part.  The  composition 
of  the  finished  bread  can  now  be  noted.  A  loaf  of  wheaten  bread  consists  of 
two  parts,  the  crumb  and  the  crusty  which  differ  somewhat  in  both  physical 
and  chemical  character.  The  crumb  is  white  in  color,  more  or  less  vesicular 
in  structure,  soft  when  fresh,  and  of  agreeable  taste  and  sweet  odor ;  the 
crust  is  harder,  more  easily  broken,  of  a  chestnut-brown  color,  and  nearly 
destitute  of  all  porous  character,  is  sweeter  in  taste,  because  of  the  ^greater 
change  of  the  starch  into  dextrin  and  maltose.  The  chemical  differences 
between  the  crumb  and  crust  of  wheat  bread  are  shown  in  several  of  the 
analyses  given  by  Von  Bibra.f 


CALCULATED  FOE  ANHYDROUS  BREAD. 

Water 
origi- 
nally 
con- 
tained 
in  the 
'  bread. 

Nitro- 
genous 
material. 

Dextrin 
and 
soluble 
starch. 

Sugar. 

Fat. 

Starch. 

"Wheaten  bread,  Nurnberg,  crumb 
Wheaten  bread,  Nurnberg,  crust  . 
Rye  bread,  Nurnberg,  crumb    .    . 
Rye  bread,  Nurnberg,  crust  .    .    . 
Wheaten  bread  from  Madrid    .    . 
Wheaten  bread  from  years  1816 
and  1817    

11.296 
10.967 
17.096 
14.838 
8.064 

8.541 

7.354 
11.296 
13.296 
6.387 

9.741 
10.903 

14.975 
16.092 
15.413 
18.275 
4.763 

10.192 

14.531 
4.363 
12.209 

5.497 

4.653 

28.269 

4.175 
4.149 
2613 
4.835 
1.470 

2184 

4.953 
2.145 
7.035 
4.420 

2.846 
6.345 

1.683 
0.715 
1.064 
0.564 
1.173 

4.233 
0.824 
1.360 
0.566 

10.948 
0.807 

67.871 
68.077 
63.814 
60.842 
84530 

79.1)83 

68.929 
81.372 
66.100 
83.130 

71.812 
53.676 

40.600 
13.000 
46.440 
12.449 
15.000 

11.606 

9.160 
11.420 
14.000 
11.780 

8.660 
18.333 

Pumpernickel    from    Westphalia 
(contained  some  bran)     .... 
Wheaten  Zweiback,  Hamburg  .    . 
Rye  Zweiback,  Bremen  

Barley  bread  from  Lower  Bavaria 
Oaten  bread  from  Bavaria  (per- 
fectly free  from  adulteration)     . 
Fine   rye    bread   from   Dalecaria 
(containing  bran)     

The  differences  between  wheat  bread  made  by  the  usual  fermentation 
process  and  wheat  bread  aerated  by  carbon  dioxide  under  pressure  (Daug- 
lish  system)  are  shown  also  in  the  following  analyses  by  Dr.  Bell :  J 

*  Chemistry  of  Wheat,  Flour,  and  Bread,  etc.,  1886,  p.  326. 
f  Stohmann  and  Kerl,  Arigewand.  Chem.,  4th  ed.,  p.  215. 
j  Analyses  and  Adulteration  of  Foods,  p.  131. 


ANALYTICAL   TESTS   AND    METHODS. 


237 


CONSTITUENTS  OF  THE  BREAD 
REDUCED  TO  DRY  STATE. 

AERATED  BREAD. 

HOME-MADE  BREAD. 

Tin  loaf. 

Cob  loaf  (Paris 
bread). 

Tin  loaf. 

Cob  loaf  (Paris 
bread). 

Crumb. 

Crust. 

Crumb. 

Crust. 

Crumb. 

Crust. 

Crumb. 

Crust. 

Starch,  dextrine,  cellulose,  etc 
Maltose 

78.93 
640 

10.30 

1.96 
0.18 
2.23 

78.96 
5.61 

11.28 

1.75 
0.16 
2.24 

82.75 
4.66 

8.58 

1.80 
0  13 
2.08 

82.82 
3.94 

9.09 

1.85 
0.17 
2.13 

78.12 
6.87 

11.65 

1.74 
0.22 
1.40 

77.62 
6.68 

11.17 

200 
1.22 
1.31 

82.05~ 
4.85 

10.59 

1.28 
0.15 
1.08 

83.42 
4.11 

8.68 

2.37 
0.39 
1.03 

N  itrogenous    matter,    insolu- 
ble in  alcohol     ...... 

Nitrogenous  matter,  soluble  in 

Fat  

Inorganic  matter  or  ash  .    .    . 

Percentage    of    moisture     in 
bread  when  new    

44.09 

19.19 

41.52 

16.48 

42.02 

22.92 

41.98 

20.02 

2.  CRACKERS  AND  HARD  BISCUIT  are  made  from  a  dough  composed 
of  flour  and  water,  with  the  addition  in  special  cases  of  a  great  variety  of 
sweetening  and  flavoring  ingredients,  such  as  milk,  eggs,  sugar,  butter  or 
lard,  spices,  and  flavoring  essences.  'The  dough  prepared  in  large  masses  is 
passed  between  rollers,  and  from  the  sheet  of  dough  so  obtained  by  other 
machines  are  cut  out  the  various  forms  desired.  Sheets  or  trays  of  these 
dough-forms  pass  by  automatic  machinery  into  and  through  long  ovens  at 
a  regulated  rate  of  speed,  which  can  be  so  controlled  as  to  give  them  exactly 
the  requisite  exposure  to  the  heat  needed  for  baking. 

IV.  Analytical  Tests  and  Methods. 

1.  FOR  THE  FLOUR. — The  moisture  is  determined  by  drying  five 
grammes  of  the  flour  in  a  water-oven  until  constant  weight  is  obtained. 

The  starch  is  estimated  from  the  amount  of  glucose  which  is  produced 
from  it  by  the  action  of  dilute  acid.  Two  grammes  of  the  flour  are  boiled 
in  a  flask  with  inverted  condenser  for  several  hours  with  some  twenty  cubic 
centimetres  of  sulphuric  acid  suitably  diluted.  When  the  conversion  of  the 
starch  is  completed  the  solution  is  neutralized  with  soda,  made  up  to  definite 
volume  with  water,  and  the  glucose  determined  with  Fehling's  solution 
either  gravimetrically  or  volumetrically,  as  described  under  glucose.  (See 
p.  159.)  After  deduction  of  the  sugar  found  in  a  previous  test  to  be  con- 
tained in  the  sample,  the  difference  is  the  amount  produced  from  the  starch, 
together  with  a  small  quantity  from  the  dextrine  and  traces  of  fibre.  One 
hundred  parts  of  glucose  correspond  to  ninety  of  the  starch. 

To  determine  the  cellulose,  a  weighed  quantity  of  the  flour  is  boiled  with 
rather  dilute  sulphuric  acid  for  ten  minutes  to  dissolve  the  starch.  A  large 
quantity  of  water  is  then  added,  and  the  undissolved  part  allowed  to  settle. 
The  residue  is  thrown  upon  a  filter,  well  washed  with  boiling  water,  and 
then  digested  with  dilute  potash  solution  to  dissolve  the  albuminous  matter. 
It  is  then  washed  upon  a  tared  filter,  dried,  and  weighed.  It  is  now 
incinerated  and  the  ash  determined.  This  subtracted  from  the  weight  of 
material  on  the  tared  filter  gives  the  cellulose  or  fibre. 

To  determine  the  sugar,  ten  grammes  of  the  flour  or  powdered  grain  are 


238 


FERMENTATION   INDUSTRIES. 


repeatedly  digested  in  alcohol  of  seventy  per  cent,  and  the  filtrate  made  up 
to  a  bulk  of  three  hundred  cubic  centimetres.  This  solution  is  first  tested 
directly  for  glucose,  but  generally  with  negative  results.  A  known  portion 
of  the  filtrate  is  then  boiled  for  four  minutes  with  five  cubic  centimetres  of 
normal  sulphuric  acid,  neutralized  with  soda  and  tested  with  Fehling's  solu- 
tion, and  the  sugar  present  reckoned  as  cane  is  calculated  from  the  result. 

The  total  nitrogenous  compounds,  and  the  portions  soluble  or  insoluble 
in  alcohol,  are  generally  determined.  Sometimes  the  portions  of  the  nitro- 
genous compounds  soluble  or  insoluble  in  water  are  determined  instead. 
In  the  latter  case  Wanklyn's  ammonia  process  (see  p.  199)  is  the  most  con- 
venient. Generally,  however,  the  distinction  made  is  into  those  albumi- 
noids soluble  and  those  insoluble  in  alcohol.  For  this  determination  ten 
grammes  of  the  flour  are  completely  exhausted  with  eighty  per  cent,  alcohol 
at  a  temperature  of  140°  F.  (60°  C.)  and  an  aliquot  portion  of  the  total 
filtrate  evaporated  to  dryness  and  weighed.  A  known  quantity  of  this 
residue  is  then  analyzed  for  nitrogen  by  the  Dumas  process  with  copper 
oxide,  and  the  nitrogen  so  obtained  multiplied  by  6.3  gives  the  albuminoids. 
The  flour  left  after  treatment  with  alcohol  is  dried,  and  a  weighed  portion 
analyzed  for  nitrogen  and  similarly  calculated  for  albuminoids  (albumen 
and  fibrin).  For  another  process  for  these  albuminoid  determinations  by 
Graham,  see  Allen,  "  Commercial  Organic  Analysis,"  2d  ed.,  vol.  i.  p.  366. 

The  gluten  is  best  determined  as  recommended  by  Wanklyn  and  Cooper.* 
Ten  grammes  of  the  flour  are  mixed  on  a  porcelain  plate  with  four  cubic 
centimetres  of  water  so  as  to  form  a  compact  dough.  This  is  placed  in  a 
conical  test-glass  or  measure,  fifty  cubic  centimetres  of  water  added,  and  the 
dough  manipulated  with  a  spatula  so  as  to  free  it  from  starch.  The 
water  is  decanted  off,  a  fresh  quan- 
tity added,  and  the  kneading  con-  FIG.  71. 
tinued  until  the  water  remains  col- 
orless. The  gluten  mass  is  then 
removed,  kneaded  in  a  little  ether, 
and  spread  out  in  a  thin  layer  on 
a  platinum  dish,  where  it  is  dried 
by  the  aid  of  a  water-oven  until 
the  weight  is  constant.  The  crude 
gluten  contains  ash  equal  to  about 
.3  per  cent,  on  the  flour  and  fat 
equivalent  to  1.00  of  the  flour. 

An  examination  of  the  crude 
gluten  as  to  its  power  of  distending 
under  the  influence  of  heat  is  often 
made  as  a  means  of  judging  of  the 
value  of  a  flour  for  bread-making. 
This  is  done  by  ~the  aid  of  the 
aleurometer  of  Boland,  shown  in 
Fig.  71.  Some  thirty  grammes  of 
the  flour  are  kneaded  as  just  de- 
scribed, and  seven  grammes  of  the  freshly-separated  crude  gluten  obtained  is 
placed  in  the  inner  vessel  as  shown  at  a  b.  In  the  mean  time,  while  the 
gluten  is  being  prepared,  the  tube  D  is  heated  by  means  of  an  oil-bath  until 


*  Bread  Analysis,  London,  1886,  p.  43. 


ANALYTICAL   TESTS  AND   METHODS.  239 

the  thermometer  T,  which  is  at  first  sunk  in  the  tube  D,  registers  150°  C. 
The  thermometer  is  then  withdrawn  and  the  aleurometer  E,  containing  the 
gluten,  put  in  its  place.  The  spirit-lamp  under  the  oil-bath  is  allowed  to 
burn  for  ten  minutes  longer  and  then  extinguished.  The  piston  G  is  grad- 
uated so  that  when  pushed  down  it  registers  25°.  When  the  gluten  swells 
and  fills  the  space  from  a  b  to  c  d  it  touches  the  bottom  of  the  piston  and  is 
at  25°.  If  it  continues  to  swell  the  reading  may  be  30°  or  35°,  as  shown  on 
the  scale  when  the  piston  is  pushed  up.  If  the  gluten  does  not  indicate  at 
least  25°  on  the  aleurometer  it  may  be  considered  unfit  for  bread-making. 
A  similar  instrument,  termed  an  aleuroseope,  has  been  invented  by  Sellnick. 

To  determine  the  fat  of  the  flour,  four  grammes  are  dried  and  repeatedly 
digested  with  ether  until  exhausted.  The  filtrates  are  evaporated  in  a  tared 
vessel  and  weighed. 

To  determine  the  ash,  ten  grammes  of  the  flour  are  incinerated  in  a 
platinum  capsule  to  a  white  ash,  which  is  then  weighed. 

Among  the  adulterations  of  flour,  besides  the  admixture  of  other 
starchy  material  of  lesser  value,  which  must  be  looked  for  with  the  micro- 
scope (see  starches,  p.  168),  the  most  frequently  occurring  is  alum.  For  the 
detection  of  this,  one  of  the  best  known  tests  is  based  upon  the  property  of 
alumina  of  forming  a  violet-  or  lavender-colored  lake  with  the  coloring 
matter  of  logwood.  Ten  grammes  of  the  flour  should  be  mixed  in  a  wide 
beaker  with  ten  cubic  centimetres  of  water,  one  cubic  centimetre  of  the 
logwood  tincture  (five  grammes  of  logwood-chips  digested  with  one  hundred 
cubic  centimetres  of  strong  alcohol)  and  an  equal  measure  of  a  saturated 
aqueous  solution  of  ammonium  carbonate  are  then  added,  and  the  whole 
mixed  together  thoroughly.  If  the  flour  is  pure,  a  pinkish  color,  gradually 
fading  to  a  dirty  brown,  is  obtained ;  whereas  if  alum  be  present,  the  pink 
is  changed  to  a  lavender  or  actual  blue.  As  a  precaution,  it  is  desirable  to 
set  the  mixture  aside  for  a  few  hours  or  to  warm  the  paste  in  the  water- 
oven  for  an  hour  or  two  and  note  whether  the  blue  color  remains. 

Or  to  separate  any  alum  from  the  flour  before  applying  the  test,  the  flour 
is  shaken  up  with  chloroform  in  a  stoppered  glass  cylinder  provided  with  a 
stopcock  below.  After  shaking  the  flour  rises  to  the  surface,  while  any  for- 
eign mineral  matter  settles  at  the  bottom,  and  may  be  run  off  with  a  little 
of  the  liquid.  The  mineral  matter  is  warmed  and  the  chloroform  gotten  rid 
of  by  the  aid  of  a  current  of  air.  It  can  then  be  examined.  Any  alum  in 
it  will  of  course  be  soluble  in  water,  and  can  be  shown  by  the  usual  tests. 
Methods  for  the  quantitative  determination  of  alum  found  as  an  adulterant 
in  flour  have  been  proposed  by  Dupre"  and  Bell  and  by  Wanklyn,  for  an 
account  of  which  the  reader  is  referred  to  Bell's  work  on  the  "  Analyses  and 
Adulteration  of  Foods." 

2.  FOR  BREAD. — The  methods  just  described  under  flour  are  almost  all 
equally  applicable  to  the  baked  bread.  To  test  bread  for  adulteration  from 
alum  a  slightly  different  procedure  is  to  be  followed.  "  To  about  a  wine- 
glassful  of  water  in  a  porcelain  capsule  five  cubic  centimetres  of  freshly- 
prepared  tincture  of  logwood  and  the  same  quantity  of  the  carbonate  of 
ammonia  solution  are  added.  A  piece  of  the  crumb  of  the  bread,  say  about 
ten  grammes,  is  then  soaked  therein  for  about  five  minutes,  after  which  the 
liquid  is  poured  away  and  the  bread  is  dried  at  a  gentle  heat.  If  alum  be 
present  the  bread  will  acquire  a  lavender  color  or  more  or  less  approaching 
dark  blue,  according  to  the  quantity  of  the  alum  which  has  been  added  ; 
whereas  if  the  color  be  a  dirty  brown,  the  bread  may  be  regarded  as  pure. 


240  FERMENTATION   INDUSTRIES. 


F.    THE  MANUFACTURE  OF  VINEGAR, 

Under  the  general  heading  of  fermentation  mention  was  made  of  the 
acetic  fermentation,  which  frequently  follows  the  alcoholic  fermentation.  It 
is  produced,  it  is  true,  by  other  species  of  ferments,  but  largely  upon  mate- 
rials susceptible  to  the  alcoholic  fermentation  or  already  changed  by  it  into 
alcohol-containing  products.  The  close  association  in  nature  of  these  two 
changes  is  readily  understood  when  the  chemical  relationship  of  alcohol  and 
acetic  acid  is  looked  at.  The  latter  is  the  simple  oxidation  product  of  the 
former,  and  the  processes  for  developing  the  alcoholic  change  in  any  sugary 
liquid,  such  as  a  beer-wort  or  a  grape-must,  have  to  be  controlled  carefully 
that  they  do  not  allow  of  this  supplementary  change  whereby  the  alcohol 
goes  over  into  acetic  acid.  The  conditions  under  which  the  acetic  fermenta- 
tion sets  in  may  be  summarized  as  follows  : 

1.  A  liquid  weak  in  alcohol,  containing  not  more  than  twelve  per  cent, 
by  weight  of  this  compound. 

2.  Abundant  access  of  air. 

3.  A  temperature  of  from  20°  to  35°  C.  (68°  to  95°  F.). 

4.  Acetic  ferments  (Mycoderma  aceti,  etc.),  together  with  the  food  neces- 
sary for  these  organisms.     Under  this  heading  of  acetic  ferments  Nageli 
distinguishes,  besides  the  Mycoderma  aceti,  the  Mycoderma  cerevisice  and 
Mycoderma  vini,  although  the  latter  of  these  is  said  by  De  Seynes  to  arrest 
the  growth  of  the  acetic  ferment  proper.     Hansen  also  mentions  a  second 
ferment  as  found  at  times  in  beer  along  with  the  Mycoderma,  or,  as  it  is 
often  termed  now,  Bacterium  aceti,  to  which  he  gives  the  name  Bacterium 
Pasteurianum. 

The  acetic  ferment,  as  before  stated  (see  p.  184),  develops  not  by  the 
budding  process  characteristic  of  the  yeast  ferment,  but  by  splitting  or  fissure 
of  the  elongated  cell.  When  these  germs,  which  originally  drop  from  the 
air,  like  the  yeast-cells,  into  the  fermenting  or  sugary  liquids,  find  a  liquid 
specially  suited  for  their  growth,  as,  for  example,  a  mixture  of  wine  and 
vinegar,  they  develop  rapidly  over  the  surface  of  the  liquid,  where  they  have 
the  necessary  oxygen  supply,  and  form  a  gelatinous  skin,  which  thickens 
and  falls  to  the  bottom  of  the  vessel  because  of  its  increasing  weight.  An- 
other skin  forms  at  once  again,  and  this  in  turn  is  replaced  by  a  third, 
and  so  on  until  the  liquid  is  completely  exhausted  of  assimilable  material. 
This  skin,  called  the  "  mother  of  vinegar,"  consists  of  a  multitude  of  these 
minute  fissure  ferments. 

I.  Raw  Materials. 

Only  such  materials  will  be  considered  here  as  give  rise  to  a  vinegar  by 
the  normal  acetic  fermentation.  The  manufacture  of  acetic  acid  and  tech- 
nically important  acetates  will  be  spoken  of  later  under  pyroligneous  acid 
as  derived  from  the  destructive  distillation  of  wood. 

The  materials  referred  to  as  furnishing  vinegar  under  the  influence  of 
the  acetic  fermentation  are,  first,  wine ;  second,  spirits ;  third,  malt- wort  or 
beer  ;  fourth,  fermented  fruit  juices  other  than  wine ;  and,  fifth,  sugar-beets. 

The  wines  used  are  both  red  and  white  wines,  and  are  such  as  are  of  in- 
ferior vintages,  and  considered  unfit  for  drinking  as  wine.  Such  wines  are 
gathered  together  from  all  sections  and  are  made  into  vinegar  largely  in 
France  at  Orleans  and  at  Paris.  The  wines  do  not  exceed  ten  per  cent. 


PROCESSES   OF   MANUFACTURE.  241 

alcoholic  strength.  Wines  about  a  year  old  are  the  best  for  vinegar-making, 
as  the  new  wines  are  prone  to  undergo  putrid  or  ropy  fermentation,  and 
older  wines  do  not  contain  sufficient  extractive  matter. 

The  spirits  used  are  chiefly  the  potato  brandy  of  Germany  and  whiskey 
in  this  country,  the  vinegar  in  either  case  being  made  by  the  "  quick  vin- 
egar" process.  These  spirits,  when  used  for  vinegar-making,  are  so  diluted 
with  water  and  vinegar  already  formed  that  the  alcoholic  strength  ranges 
between  three  and  ten  per  cent. 

The  malt-wort  used  for  vinegar-making  is  exactly  like  that  prepared  for 
grain  spirit  manufacture,  unmalted  grain  and  malt  being  used  admixed,  and 
the  alcoholic  fermentation  being  pushed  so  as  to  produce  the  maximum 
amount  of  alcohol  from  the  converted  starch  of  the  grain.  When  the  alco- 
holic fermentation  is  completed  it  is  allowed  to  stand  for  some  days  in  the 
fining-vats,  where  all  dead  yeast  and  cloudiness  subside,  and  it  is  then  made 
to  pass  through  a  filter-bed  of  wood-chips  into  the  acetifier.  The  unmalted 
grain  used  in  the  preparation  of  the  wort  must  be  thoroughly  dried  in  a 
kiln  previous  to  crushing  in  order  that  many  of  the  glutinous  and  albumi- 
noid matters  may  be  destroyed.  These  would  otherwise  interfere  with  the 
keeping  qualities  of  the  vinegar.  Sour  ale  or  beer  is  said  not  to  yield  good 
vinegar,  but  a  product  very  liable  to  undergo  putrid  fermentation,  a  very 
disagreeable  smell  being  imparted  to  the  vinegar  in  consequence. 

Cider  from  apples  and  Perry  from  pears  are  about  the  only  fruit  juices 
besides  wine  fermented  for  the  production  of  vinegar.  Cider  from  good, 
sweet,  and  ripe  apples  serves  for  the  manufacture  of  cider  vinegar  in  this 
country.  The  cider  is  the  product  of  a  spontaneous  alcoholic  fermentation 
of  the  apple  juice,  and  the  vinegar  formation  is  merely  a  continuation  of 
this  spontaneous  change.  Perry  vinegar  is  made  to  some  extent  in  Eng- 
land, and  a  vinegar  from  crab-apples  in  Wales. 

Sugar-beets  are  used  somewhat  in  France  for  vinegar-making.  The 
beets  are  rasped  to  a  fine  pulp  and  pressed.  The  juice  is  diluted  with  water 
and  boiled.  After  cooling,  yeast  is  added  and  the  alcoholic  fermentation 
developed,  and  this  product  mixed  .with  vinegar  and  treated  as  the  other 
alcoholic  liquids  before  mentioned  for  the  development  of  the  acetic  fermen- 
tation. 

Artificial  glucose,  cane-sugar,  and  molasses  have  also  been  used  in  Eng- 
land for  the  production  of  vinegars  which  are  used  to  adulterate  malt 
vinegar. 

IE.  Processes  of  Manufacture. 

1.  THE  ORLEANS  PROCESS. — This  is  the  process  by  which  wine  vinegar 
is  made  in  France  and  Germany,  and  is  the  oldest  in  practical  use  of  the 
several  methods  now  employed.  The  wine  which  is  to  be  acetified  is  allowed 
to  stand  for  a  time  over  wine-lees,  and  then  clarified  by  being  passed  through 
vats  containing  beech-shavings.  The  oaken  acetifying  vessels,  holding  from 
fifty  to  one  hundred  gallons,  and  known  as  "  mother-casks,"  are  first  steamed 
out  and  then  soured  with  boiling  vinegar,  which  is  made  to  fill  one-third 
of  the  cask.  The  wine  is  now  added  in  instalments  of  .ten  litres  every  eight 
days  until  the  cask  has  become  more  than  half-full,  when  one-third  of  its 
contents  are  siphoned  off  into  storage-vats  and  the  periodical  addition  of 
wine  continued  as  before.  The  "  mother-casks,"  or  acetifiers,  can  be  used 
in  this  way  continuously  for  years  unt'.l  the  sediment  of  yeast,  argols,  and 
impurities  makes  it  necessary  to  give  them  a  thorough  cleaning.  The  vin- 

16 


242 


FERMENTATION   INDUSTRIES. 


egar  obtained  in  this  way  has  a  very  agreeable  aroma,  that  made  from  white 
wines  being  most  esteemed.  When  the  wines  employed  in  the  Orleans 
process  are  too  weak  it  often  happens  that  the  vinegar  is  ropy  and  wanting 
in  transparency.  In  such  case  it  must  undergo  the  firing  process.  The 
progress  of  the  acetification  is  judged  of  by  plunging  in  a  rod  and  examin- 
ing the  froth  upon  it  when  withdrawn.  This  should  be  white  and  copious. 
The  temperature  that  is  found  to  answer  best  is  between  24°  and  26.6°  C. 
(75°  and  80°  F.) 

Hengstenberg  has  proposed  a  modification  of  the  Orleans  process, 
whereby  a  series  of  the  "  mother-casks"  are  connected  together  at  the  base 
by  short  pieces  of  glass  tubing.  After  the  acetification  of  the  first  addition 
of  wine  in  each  cask  the  new  wine  is  added  only  to  the  first  cask,  into  which 
it  runs  slowly,  while  from  the  last  cask  of  the  series,  by  means  of  a  siphon- 
tube  fixed  in  the  side,  the  excess  flows  off  as  finished  vinegar.  The  increase 
of  yield  by  this  modification  is,  however,  only  slight, 

2.  THE  QUICK-VINEGAR  PROCESS. — This  process  was  first  introduced 
by  Schutzenbach  in  1823,  and  has  been  considerably  improved  since.  It 
is  used  exclusively  in  the  case  of  spirit  vinegar  in  Germany  and  in  this 
country,  and,  with  slight  modifications,  in  England  for  malt  vinegar.  The 
vinegar-formers  are  upright  casks  from  six  to  twelve  feet  in  height  and 
three  to  five  feet  in  diam- 
eter. About  a  foot  above  FIG. 
the  true  bottom  of  the 
cask  it  has  a  false  bottom 
perforated  like  a  sieve. 
Upon  this  beech-wood 
shavings  are  heaped,  ex- 
tending nearly  to  the  top 
of  the  cask.  Between 
the  true  and  false  bot- 
toms and  just  under  the 
latter  a  series  of  holes  is 
bored  in  the  cask  in  a 
direction  slanting  down- 
ward and  extending 
around  the  entire  cask. 
The  beech-shavings  are 
first  boiled  in  water  and 
dried.  They  are  then 
soured  or  soaked  in  warm 
vinegar  for  twenty-four 
hours,  filled  into  place 
and  covered  by  a  wooden 
disk  perforated  by  fine 
holes  in  which  pack- 
thread is  loosely  filled. 
This  disk  also  is  perfo- 
rated by  four  larger  glass 

tubes  open  at  both  ends,  which  serve  as  air-vents.  The  cask  is  then  closed 
on  top  by  a  wooden  cover  with  a  single  hole  in  the  centre,  through  which  the 
alcoholic  liquid  is  to  be  poured  and  from  which  air  may  escape.  The  entire 
arrangement  may  be  understood  from  Fig.  72.  During  the  oxidation  of  the 


PROCESSES   OF   MANUFACTURE.  243 

alcoholic  liquid  considerable  heat  is  developed,  and  a  current  of  air  is  thus 
made  to  enter  through  the  circle  of  holes  under  the  false  bottom  and  rise 
through  the  wet  shavings,  escaping  through  the  opening  at  the  top.  The 
diluted  spirits  or  mixture  to  be  acetified  are  poured  into  the  top  of  each  vat, 
and  as  they  flow  off,  by  the  aid  of  a  siphon  arrangement  from  the  base  they 
are  introduced  into  the  top  of  the  second  vat.  If  not  over  four  per  cent, 
of  alcohol  were  contained  in  the  original  liquid,  that  drawn  off  from  the 
second  vat  will  be  converted  into  good  vinegar.  The  temperature  of  the 
vinegar-forming  casks  should  be  about  35°  C.  (95°  F.).  Above  this  there 
is  too  much  loss  of  alcohol  and  aldehyde  by  evaporation ;  below  it,  the 
oxidation  goes  too  slowly.  If  the  minute  organisms  known  as  "  vinegar 
eels"  show  themselves,  hot  vinegar  is  poured  in  on  top  until  it  shows  a 
temperature  of  50°  C.  (122°  F.)  on  running  off,  which  kills  them. 

Whiskey,  brandy,  and  grain  spirit  properly  diluted  are  all  acetified  by 
the  aid  of  this  quick- vinegar  process.  To  these  diluted  spirits  a  small 
amount  of  malt  infusion  is  generally  added  to  furnish  nutritive  matter  for 
the  development  of  the  acetic  ferment,  which  in  this  process  as  in  the  pre- 
ceding is  the  agency  whereby  the  atmospheric,  oxidation  becomes  effective  in 
changing  alcohol  into  acetic  acid. 

3.  MANUFACTURE  OF  MALT  VINEGAR. — This  is  effected  by  a  process 
much  resembling  the  quick-vinegar  process.     The  acetifiers  are,  however, 
much  larger,  holding  from  eight  thousand  to  ten  thousand  gallons.     Their 
construction  is  shown  in  Fig.  73.  *  Bundles  of  birch-twigs,  J5,  are  sup- 
ported upon   a   perforated   bottom, 
from  which  the  liquid  trickles  in  fine 
streams.     The  malt-wort  fed  in  be- 
low is  warmed  by  a  closed  steam- 
coil  of  block-tin,  and  pumped  to  the- 
top  of  the  casks,  where  it  is  sparged,, 
or  sprinkled,  in  fine  streams  over 
the  birch-twigs,  and  the  process  re- 
peated until  the  vinegar  shows  the 
requisite    strength.      These    birch- 
twigs   have   been   previously   freed 
from  all  juice  and  coloring  matter 
by  repeated  boiling  with  water,  and 
are  soured  before  starting  the  spar- 
ging.    The  entire  process  of  making 
malt  vinegar    requires    about   two 

months.  The  temperature  at  the  beginning  of  the  process  is  about  43°  C. 
(110°  F.),  and  later  is  kept  at  38°  C.  (100°  F.). 

4.  THE  MANUFACTURE  OF  CIDER  VINEGAR. — As  before  stated,  this 
is  largely  a  spontaneous  fermentation.     The  fresh  cider  is  allowed  to  fer- 
ment in  barrels  having  the  bung-hole  open,  which  are  exposed  to  the  sun 
or  placed  in  a  warm  cellar.     The  acetification  is  often  made  a  progressive 
change  by  adding  fresh  quantities  of  cider  to  the  barrel  every  few  weeks ; 
the  addition  of  "  mother  of  vinegar"  also  is  made  to  accelerate  the  change. 

5.  PASTEUR'S  PROCESS  FOR  VINEGAR-MAKING  BY  DIRECT  USE  OF 
THE  VINEGAR  FUNGUS. — Pasteur  takes  an  aqueous  liquid  containing  two 
per  cent,  of  alcohol  and  one  per  cent,  of  vinegar  and  small  amounts  of  phos- 
phates of  potassium,  magnesium,  and  lime,  and  in  this  propagates  the  acetic 
ferment  (Mycoderma  aceti).     The  plant  soon  spreads  out  and  covers  the 


244  FERMENTATION    INDUSTRIES. 

whole  surface  of  the  liquid,  at  the  same  time  acetifying  the  alcohol.  When 
one-half  of  the  alcohol  has  been  changed  small  quantities  of  wine  or  alcohol 
mixed  with  beer  are  added  daily  until  the  acetification  slackens,  when  the 
vinegar  is  drawn  off  and  the  "  mother  of  vinegar"  collected,  washed,  and 
used  again  with  a  freshly-prepared  mixture.  When  wine  or  beer  are  used, 
the  addition  of  the  phosphate  salts  as  food  for  the  plant  is  unnecessary,  but 
when  pure  alcohol  is  used  they  are  needed.  Vinegar  prepared  by  this 
process  is  said  to  possess  the  agreeable  aroma  of  wine  vinegar. 

m.  Products. 

Wine  Vinegar  varies  in  color  from  light  yellowish  to  red,  according  as  it 
has  been  derived  from  white  or  red  wines,  that  from  the  former  being  the 
most  highly  esteemed.  The  vinegar  from  red  wines,  however,  can  be  decol- 
orized by  filtration  through  purified  bone-black.  Skimmed  milk  is  also  used 
for  the  same  purpose.  When  thoroughly  agitated  with  the  vinegar  the 
casein  coagulates  and  carries  down  with  it  the  greater  part  of  the  coloring 
matter  of  the  vinegar,  besides  clarifying  it.  It  is  not  used,  however,  so 
much  as  the  filtration  through  charcoal.  Wine  vinegar  has  a  specific  gravity 
1.014  to  1.022,  and  contains  from  six  to  nine  per  cent,  (rarely  twelve)  of 
absolute  acetic  acid.  When  freshly  made,  it  contains  traces  of  alcohol  and 
aldehyde.  The  amount  of  acid  potassium  tartrate  (tartar)  contained  in  wine 
vinegar  averages  .25  per  cent.  Its  presence  is  peculiar  to  this  variety  of 
vinegar. 

Malt  and  Beer  Vinegars  have  a  higher  specific  gravity  (1.021  to  1.025), 
and  contain  dissolved  dextrin,  maltose,  soluble  albuminoids,  and  similar  con- 
stituents of  the  malt  extract.  This  kind  of  vinegar  on  evaporation  leaves  a 
glutinous  residue  only  sparingly  soluble  in  alcohol.  It  contains  from  three 
to  six  per  cent,  of  acetic  acid. 

Spirit  Vinegar  is  colorless  as  produced,  but  is  frequently  colored  with 
caramel-color  to  imitate  the  appearance  of  wine  or  cider  vinegar.  It  con- 
tains from  three  to  eight  per  cent,  of  acetic  acid,  although  the  so-called 
"vinegar  essence"  (double  vinegar)  may  contain  as  much  as  fourteen  per  cent. 

Older  Vinegar  is  yellowish-brown,  has  an  odor  of  apples,  a  density  of 
1.013  to  1.015,  and  contains  from  three  and  a  half  to  six  per  cent,  of  acetic 
acid.  It  is  distinguished  from  the  other  varieties  by  yielding  on  evaporation 
a  mucilaginous  extract  smelling  and  tasting  of  baked  apples  and  containing 
malic  acid,  which  replaces  the  tartaric  acid  of  the  wine  vinegar.  The  differ- 
ences between  cider  vinegar  and  whiskey  vinegar  as  manufactured  in  this 
country  are  shown  in  the  accompanying  analyses  by  Battershall  :* 

Cider  vinegar.  Whiskey  vinegar. 

Specific  gravity 1.0168  1.0107 

Specific  gravity  of    the    distillate 

from  neutralized  sample  ....                0.9985  0.9973 

Acetic  acid 4.66  7.36 

Total  solids 2.70  0.15 

Total  ash 0.20  0.038 

Potassa  and  phosphoric  acid  in  ash  .          Considerable.  None. 

Heated  with  Fehling's  solution  .    .     Copious  reduction.  No  reduction. 

Treated  with  basic  lead  acetate  .    .  Flocculent  precipitate.  No  precipitate. 

Glucose,  or  Sugar,  Vinegar,  prepared  from  different  saccharine  and 
amylaceous  materials  by  conversion  with  dilute  acid,  followed  by  fermenta- 

*  Food  Adulteration  and  Detection,  New  York,  1887,  p.  230. 


ANALYTICAL   TESTS   AND    METHODS.  245 

tion  and  acetification,  contains  dextrose,  dextrin,  and  often  calcium  sulphate 
(from  commercial  glucose).  It  is  said  to  be  employed  in  France  and  Eng- 
land for  adulterating  wine  or  malt  vinegars. 

Factitious  Vinegars  are  often  made  from  pyroligneous  acid  flavored  with 
acetic  ether  and  colored  with  caramel-color.  Such  a  product  differs  from 
malt  vinegar  in  containing  no  phosphates,  and  from  wine  or  cider  vinegar 
in  the  absence  of  tartaric  or  malic  acids  respectively. 

IV.  Analytical  Tests  and  Methods. 

The  determination  of  the  acetic  acid  is  usually  done  by  titration  with 
standard  alkali,  using  phenolphthalem  as  indicator.  In  the  presence  of 
free  sulphuric  acid,  it  is  necessary  to  distil  a  measured  quantity  of  the  sam- 
ple almost  to  dryness  and  titrate  the  distillate,  it  being  assumed  that  eighty 
per  cent,  of  the  total  acetic  acid  present  passes  over. 

The  determination  of  the  extract  or  solid  residue  in  vinegar  is  executed 
in  the  same  manner  as  described  under  beer  or  wine. 

The  test  for  sulphuric  acid  is  an  important  one.  In  England,  the  manu- 
facturers were  allowed  by  law  to  add  one  part  of  sulphuric  acid  by  volume 
to  one  thousand  of  vinegar  in  order  to  protect  weak  vinegar  from  the  putrid 
fermentation.  This  addition  is  not  necessary  in  good  vinegar  and  is  not 
generally  followed  at  present.  Still,  it  may  be  present,  and  is  to  be  looked 
for  in  all  vinegars.  The  usual  test  with  basic  chloride  is  inoperative  here, 
as  sulphates  may  be  present  in  the  vinegar  from  the  water  used,  etc.  Heh- 
ner's  test  for  free  mineral  acids  (sulphuric  and  hydrochloric),  now  regarded 
as  satisfactory  in  this  case,  is  based  on  the  fact  that  acetates  and  most  other 
salts  of  organic  acids  are  decomposed  by  ignition  into  carbonates,  having 
an  alkaline  reaction  to  litmus,  while  sulphates  and  chlorides  of  the  light 
metals  are  unchanged  on  ignition  and  possess  a  neutral  reaction.  To  de- 
termine the  amount  of  free  mineral  acid  it  is  sufficient  therefore  to  care- 
fully neutralize  the  vinegar  with  standard  solution  of  soda  before  evapora- 
tion to  dryness  (the  same  process  serving  for  a  determination  of  the  total 
free  acid),  ignite  the  residue,  and  titrate  the  aqueous  solution  of  the  ash  with 
standard  acid.  If  the  free  acid  originally  present  were  wholly  organic,  the 
ash  will  contain  an  equivalent  amount  of  alkaline  carbonate,  which  will  re- 
quire an  amount  of  standard  acid  for  its  neutralization  exactly  equivalent  to 
the  amount  of  standard  alkali  originally  added  to  the  vinegar.  Any  defi- 
ciency in  the  amount  of  standard  acid  required  for  neutralization  is  due  to 
the/ree  mineral  acid  originally  present  in  the  vinegar. 

The  tartaric  acid,  a  normal  constituent  of  wine  vinegar,  may  be  tested 
for  by  evaporating  to  dryness  and  treating  the  extract  with  alcohol,  which 
dissolves  nearly  everything  but  the  tartar  or  acid  potassium  tartrate.  On 
pouring  olf  the  alcohol  and  dissolving  this  in  a  little  hot  water  its  nature 
can  be  easily  shown  by  the  usual  tests  for  tartaric  acid. 

Caramel  is  recognized  by  extracting  the  solid  residue  with  alcohol  and 
evaporating  the  solution  to  dryness ;  in  its  presence  the  residue  now  obtained 
will  possess  a  decidedly  dark  color  and  a  bitter  taste. 

Metallic  impurities,  such  as  lead,  copper,  and  zinc,  are  at  times  to  be 
found  arising  from  the  use  of  metallic  vessels  for  storing  the  vinegar. 
Arsenic  has  also  been  found  as  an  impurity  through  the  use  of  impure  sul- 
phuric or  hydrochloric  acid.  They  are  all  detected  by  the  usual  qualitative 
tests. 


246  FERMENTATION   INDUSTRIES. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

ON    FERMENTATION   AND   ITS   INDUSTRIES    IN   GENERAL. 

1879. — Studies  on  Fermentation,  M.  Pasteur,  translated  by  Faulkner  and  Robb,  London. 
Lehrbuch  der  Gahrungs-Chemie,  A.  Mayer,  3te  Auf.,  Heidelberg. 
Theorie  der  Gahrung,  C.  von  Nageli,  Miinchen. 
1882. — Chevallier's  Dictionnaire  des  Alterations,  etc.,  6me  ed.,  Baudrimont,  Paris. 

Untersuchungen  iiber  niedere  Pilze,  Nageli,  Miinchen. 

1883. — The  Brewer,  Distiller,  and  Wine  Manufacturer,  J.  Gardner,  Philadelphia. 
1884. — Falsifications  des  Matieres  alimentaires,  Laboratoire  Municipal,  2e  Rapport,  Paris. 

Bacteria  and  Yeast  Fungi,  W.  B.  Grove,  London. 
1887.— United  States  Department  of  Agriculture,  Bulletin  No.  13,  Part  iii.  (Fermented 

Alcoholic  Beverages),  C.  A.  Crampton,  Washington. 
Fermentation,  P.  Schiitzenberger  (Inter.  Science  Series),  New  York. 
1888. — Ferments  et  Fermentations,  L.  Gamier,  Paris. 
1889. — Les  Fermentations,  E.  Bourguelot,  Paris. 

Chemie  der  menschlichen  Nahrungsmittel,  J.  Konig,  3te  Auf.,  Berlin. 
1892. — Unterschungen  aus  der  Praxis  der  Gahrungs-Industrie,  E.  Ch.  Hansen,  zwei  Hefte, 

Miinchen. 
1893. — Die  Micro-organismen  der  Gahrungs-Industrie,  A.  Jorgensen,  3te  Auf.,  Berlin. 

Micro-organisms  and  Fermentation,  A.  Jorgensen,  translated  by  A.  K.  Miller  and 

E.  A.  Lennholm,  London. 
1896. — Practical  Studies  in  Fermentation,  E.  Ch.  Hansen,  translated  by  A.  K.  Miller, 

New  York. 
1898. — Les  Enzymes  et  leur  applications,  J.  Effront,  Paris. 

Technical  Mycology,  the  Utilization  of  Micro-organisms,  etc.,  F.  Lafar,  translated 

by  Chas.  T.  C.  Salter,  vol.  i.,  Philadelphia. 

1899. — The  Soluble  Ferments  and  Fermentation,  J.  Reynolds  Green,  Cambridge,   Eng- 
land. 

1900. — Die  Diastasen  und  ihre  rolle  in  der  Praxis,  J.  Effront,  iibersetzt  bei  M.  Biicheler, 
Band  i.,  Leipzig. 

ON    MALTING   AND    BREWING   AND    THEIR   PRODUCTS. 

1876. — Etudes  sur  la  Biere,  ses  Maladies,  etc.,  M.  Pasteur,  Paris. 

Die  Bierbrauerei  und  Malzextract-Fabrikation,  H.  Rudinger,  Leipzig. 
1877. — Hops :  their  Cultivation,  Commerce,  and  Uses,  P.  L.  Simmonds,  London. 
1878. — Die  Chemie  des  Bieres,  Reischauer  und  Griessmayer,  Augsburg. 

Lehrbuch  der  Bierbrauerei,  C.  Lintner,  Braunschweig. 

1880. — Die  Fabrikation  von  Malz,  Malzextract,  und  Dextrin,  J.  Bersch,  Berlin. 
1881. — Malting  and  Brewing,  Jas.  Steele,  London  and  New  York. 
1882. — Preparation  of  Malt  and  Fabrication  of  Beer,  Thaussing,  edited  by  Schwarz  and 

Bauer,  Philadelphia  and  London. 

1884. — Handbuch  der  Bierbrauerei,  L.  von  Wagner,  6te  Auf.,  2  Bde.,  Braunschweig. 
1886.— Die  Malz-Fabrikation,  K.  Weber. 

1887. — Praktisches  Hand-  und  Hilfsbuch  fur  Bierbrauer,  Pelz  und  Habich,  Braunschweig. 
1888.— The  Theory  and  Practice  of  Modern  Brewing,  F.  Faulkner,  2d  ed.,  London. 
1889. — Manuel  pratique  de  la  Fabrication  de  la  Biere,  P.  Boulin,  Paris. 

The  Microscope  in  the  Brewery,  Matthews  and  Lott,  London. 
1890. — Grundriss  der  Chemie  fur  Brauer  und  Malzer,  T.  Langer,  2te  Auf. 

Malt  and  Malting,  H.  Stopes,  New  York. 
1891.— Handbuch  der  Bierbrauerei,  E.  Ehrich,  5te  Auf.,  Halle. 

Chemistry  in  the  Brewing-Room,  C.  H.  Piesse,  London. 

Text-Book  of  the  Science  of  Brewing,  edited  by  Morritz  and  G.  H.  Morris,  London. 
1892. — Untersuchung  des  Maizes,  Windisch,  Berlin. 

La  Biere,  L.  Lindet,  Paris. 
1893. — La  Biere,  H.  Boucheron,  Paris. 

Handbuch  der  Brauwissenschaft,  Morritz  und  Morris,  bearbeitet  von  W^indisch, 

Berlin. 

1894. — Die  Bierbrauerei,  Dr.  B.  von  Posanner,  Wien. 
1895.— Systematic  Book  of  Practical  Brewing,  E.  R.  Southby,  3d  ed.,  London. 

Handy-Book  for  Brewers  and  Practical  Guide  to  Malting,  H.  E.  Wright,  2d  ed., 

London. 

1897. — The  Principles  and  Practice  of  Brewing,  W.  J.  Sykes,  London. 
1898.— The  Laboratory  Text-Book  for  Brewers,  L.  Briant,  2d  ed.,  London. 
1899.— La  Pratique  du  Maltage,  L.  Levy,  Paris. 


BIBLIOGRAPHY  AND   STATISTICS.  247 


ON    WINES. 


1872. — Treatise  on  the  Origin,  Nature,  and  Varieties  of  Wine,  Thudichum  and  Dupre, 

London. 

1873. — Etudes  sur  le  Vin,  ses  Maladies,  etc.,  M.  Pasteur,  2me  ed.,  Paris. 
1878.— Die  Behandlung  des  Weines,  J.  Nessler,  3te  Auf.    Stuttgart. 

Die  Weinbereitung,  H.  Dahlen,  Braunschweig 

Der  Wein  und  sein  Wesen,  J.  Bersch,  Wien. 

Die  Kiinstliche  Weinbereitung,  F.  J.  Dochnahl,  3te  Auf.,  Frankfort. 
1879. — Die  Bereitung  des  Schaumweines,  etc.,  A.  von  Regner,  Wien. 

Ueber  die  Chemie  des. Weines,  C.  Neubauer,  Wiesbaden. 
1881. — Handbuch  des  Weinbaues,  etc.,  A.  von  Babo,  2  Bde.,  Braunschweig. 
1883.— Die  Bestandtheile  des  Weines,  C.  Reitlechner,  2te  Auf.,  Wien. 
1884. — Die  Weinanalyse,  Max  Barth,  Leipzig. 

Anleitung  zur  chemischen  Analyse  des  Weines,  Eug.  Borgmann,  Wiesbaden. 

Die  Chemie  der  Rothweine,  E.  Roth,  2te  Auf.,  Heidelberg. 

A  History  of  Champagne,  H.  Vizetelly,  London. 
1888. — Die  Praxis  der  Weinbereitung,  J.  Bartsch. 
1889. — Manuel  de  1' Analyse  des  Vins,  E.  Barillot,  Paris. 

Chimie  des  Vins,  A.  de  Saporta,  Paris. 

Wines  and  Vines  of  California,  F.  E.  Wait,  San  Francisco. 

Practische  Anleitung  feinste  Desertweine,  etc.,  darzustellen,  L.  Gall,  4te  Auf., 

Wien. 

1890. — Traite  theorique  et  pratique  du  Travail  des  Vins,  2  vols.,  3me  ed.    E.  Maumene, 
Paris. 

The  Cider-Maker's  Handbook,  J.  M.  Trowbridge,  New  York. 
1891. — Examen  sommaire  des  Boissons  Falsifiees,  Hebert,  Paris. 

Sophistication  et  Analyse  des  Vins,  A.  Gautier,  4me  ed.,  Paris. 
1892.— Le  Vin  et  T  Art  de  la  Vinification,  Victor  Cambon,  Paris. 

Analyse  des  Vins,  M.  de  la  Source,  Paris. 

Die  Champagne-Fabrikation.  Adal  Piaz,  Wien. 

L'Essai  commercial  des  Vins  et  des  Vinaigres,  Dujardin,  Paris. 
1894. — Die  Bereitung,  Pflege,  etc.,  des  Weines,  J.  Nessler,  6te  Auf.,  Stuttgart. 
1896. — Manuel  general  des  Vins,  E.  Robinet,  5me  ed.,  3  vols.,  Paris. 
1899. — Precedes  modernes  de  Viniflcation,  2me  ed.,  Coste-Floret,  Montpellier. 

Traite  pratique  d'Analyse  chimique  des  Vins,  J.  Roussel,  Paris. 

ON    SPIRITS   AND    DISTILLED    LIQUORS. 

1875. — Chemical  Examination  of  Alcoholic  Liquors,  A.  B.  Prescott,  New  York. 

1876. — Die  Branntweinbrennerei,  C.  Stammer,  Braunschweig. 

1879. — Treatise  on  the  Manufacture  of  Alcoholic  Liquors,  P.  Duplais,  translated  by  M. 

McKennie,  Philadelphia. 

1881. — Die  Liqueur-Fabrikation,  A.  Gaber,  3te  Auf.,  Leipzig. 

1885. — Practical  Treatise  on  the  Distillation,  etc.,  of  Alcohol,  Wm.  T.  Brannt,  Philadel- 
phia. 

Die  KartofFel  und  Getreidebrennerei,  A.  Wiefert,  Wien. 
1886. — Die  Fabrikation  von  Rum,  Arrak,  Cognac,  etc.,  A.  Gaber,  Leipzig. 
1889. — Ueber  Branntwein,  seine  Darstellung,  etc.,  Dr.  Eugen  Sell,  Berlin. 
1890.— Ueber  Cognac,  Rum  und  Arrak,  etc.,  Dr.  Eugen  Sell,  Berlin. 

La  Fabrication  de  1'Alcool,  7  Fascicules,  J.  P.  Roux,  Paris. 

Traite  de  la  Distillation,  Fritsch  et  Guillemin,  Paris. 
1891. — Die  Cognac  und  Weinspirit  Fabrikation,  A.  del  Piaz,  Wien. 

Untersuchungs-Methoden  der  Spiritus  und  Industrie,  E.  Bauer,  Braunschweig. 
1892. — Nouveau  traite  de  la  Fabrication  des  Liqueurs,  etc.,  Fritsch  et  Fesq,  Paris. 
1893. — Les  Eaux-de-Vie  et  la  Fabrication  du  Cognac,  A.  Baudoin,  Paris. 

Manufacture  of  Liquors  and  Preserves,  J.  de  Brevans,  New  York. 

The  Manufacture  of  Spirit,  J.  A.  Nettleton,  London. 
1894. — Manuel  des  Fabricants  d'Alcools,  Barbet  et  Aracheguesne,  Paris. 

Handbuch  der  Spiritus-Fabrikation,  M.  Maercher,  6te  Auf.,  P.  Parey,  Berlin. 

Die  Spiritus-Fabrikation,  Essigerzeugung  und  Weinbereitung,  Dr.  B.  von  Posan- 

ner,  Wien. 
1895.— La  Chimie  du  Distillateur,  M.  P.  Guichard,  Paris. 


1899.— Traite  complet  de  la  Fabrication  de  1'Alcool,  etc.,  G.  Dejaghe,  Lille. 

Les  Eaux-de-Vie  et  Liqueurs,  X.  Rocques,  Paris. 

Manuel  pratique  de  T Analyse  des  Alcools  et  des  Spiritueux,  Girard  et  Cuniasse, 

Paris. 
1900.—  Traite  de  la  Fabrication  des  Liqueurs  et  de  la  Distillation,  P,  Duplais,  7me  ed.,  Paris. 


248 


FERMENTATION    INDUSTRIES. 


1867. 
1868. 
1871. 
1876. 
1877. 
1880. 
1885. 
1890. 

1892. 
1895, 


ON    MANUFACTURE    OF    VINEGAR. 

-Die  Essig,  Zucker  und  Starkefabrikation,  F.  J.  Otto,  Braunschweig. 
-Etudes  sur  le  Vinaigre,  M.  Pasteur,  Paris. 

-Manufacture  of  Vinegar,  H   Dussauce,  Philadelphia  and  London. 
-Lehrbuch  der  Essigfabrikation,  P.  Bronner,  Braunschweig. 
-Die  Essigfabrikation,  J.  C.  Leuchs,  7te  Auf. 
-Fabrication  industrielle  des  Vinaigres,  Claudon,  Paris. 
-Acetic  Acid  and  Vinegar,  John  Gardner,  Philadelphia. 

-Vinegar:  a  Treatise  on  the  Manufacture  of  Vinegar,  etc.,  Wm.  T.  Brannt,  Phil- 
adelphia. 

-L'Essai  commercial  des  Vins  et  des  Vinaigres,  Dujardin,  Paris. 
-Die  Essigfabrikation,  Dr.  J.  Bersch,  4te  Auf.,Wien. 


ON    FLOUR   AND    BREAD. 

1871.— Die  Getreidearten  und  das  Brod,  Von  Bibra,  Niirnberg. 

1878. — Das  Brodbacken,  K.  Birnbaum,  Braunschweig. 

1880.— The  Chemistry  of  Bread-Making  (Lectures  before  Society  of  Arts),  Chas.  Graham, 

London. 
1884. — Die   Fabrikation   des   Mehls   und  seine  neben   Producte,    H.    Meyer,    2   Theile, 

Leipzig. 
1886. — Bread  Analysis,  Wanklyn  and  Cooper,  2d  ed.,  London. 

United  States  Department  of  Agriculture,  Bulletins  Nos.  1,  4,  9  (American  Cereals), 

C.  Richardson,  Washington. 

The  Chemistry  of  Wheat,  Flour,  and  Bread,  W.  Jago,  Brighton. 
1889.— Handbuch  der  Presshefe-Fabrikation,  Otto  Durst,  Berlin. 

United  States    Department  of  Agriculture,  Bulletin  No.   13,  Part  v.   (Baking- 
Powders),  C.  A.  Crampton,  Washington. 

1890.— Presshefe,  Kunsthefe  und  Backpulver,  A.  Wilfert,  2te  Auf.,  Wien. 
1892. — Le  Pain  et  la  Viande,  J.  de  Brevans,  Paris. 

The  Dietetic  Value  of  Bread,  J.  Goodfellow,  London. 

1895.— Text-Book  of  Science  and  Art  of  Bread-Making,  W.  Jago,  London. 
1897.— Modern  Flour-Milling,  W.  R.  Voller,  3d  ed.,  Gloucester,  Eng. 


STATISTICS. 


I.       PRODUCTION   OF    HOPS   THROUGHOUT   THE   WORLD. 

The  hop  crop  of  the  world  for  the  years  1892  and  1893  is  thus  given 
by  Earth  &  Sons,  of  Nuremberg  (U.  S.  Consular  Report,  Nov.,  1893) : 

1892.  1893. 

Germany 49,029,200  pounds.         24,800,000  pounds. 

France 4,700,000  2,400,000 

Bohemia 9,000,000  11,500,000 

Remainder  of  Austria 3,000,000  3,000,000 

Belgium  and  Holland 7,400,000  8,000,000 

Russia 4,500,000  6,500,000 

Great  Britain 41 ,000,000  35,000,000 

America 36,500,000  38,500,000 

Australia 1,600,000  1,500,000 

156,729,200       "  131,200,000       " 

The  United  States  imports  a  limited  quantity  of  hops,  but  exports 
much  larger  amount.     The  figures  for  recent  years  were : 


Imports,  in  pounds  .    . 
Valued  at     .    .    .    . 
Exports,  in  pounds  . 
Valued  at 

1896. 
.    2,772,045 
.     |600,419 
.  16,765,254 
$1,478,919 

1897. 

3,017,821 
$629,987 
11,426,241 
$1,304,183 

1898. 
2,375,922 
$648,155 
17,161,669 
$2,642,779 

1899. 
1,319,319 
$591,755 
21,145,512 
$3.626.144 

BIBLIOGRAPHY   AND   STATISTICS.  249 

II.  a.  DEVELOPMENT  OF  THE  BEER  PRODUCTION  IN  THE  UNITED  STATES. 

According  to  the  reports  of  the  Commissioner  of  Internal   Revenue, 

there  were  brewed  in  the  United  States  the   following  amounts  of  malt 
liquors 

1897.                                      1898.  1899. 

Barrels  (31  gals.).            Barrels  (31  gals.).  Barrels  (31  gals.). 

New  York     .....    9,493,620                     10,093,450  -9,680,308 

Pennsylvania    ....    3, 902, 301                       4,245,972  4,299,110 

Illinois 3,244,896                      3,601,163  3,550,560 

Wisconsin 2,673,948                      2,886,502  2,846,233 

Ohio 2,631,669                      2.886,830  2,786,460 

Missouri 2,254,926                      2,435,700  2,276,088 

New  Jersey 2,001,496                      2,110,310  2,050,593 

Massachusetts    ....    1,670,556                       1,805,508  1,763,989 

Other  States 6,589,470                      7,463,904  7,444,287 

34,462,882                     37,529,339  36,697,634 


II.    b.    CONSUMPTION    OF    MALT    LIQUORS    IN    THE    UNITED    STATES. 

The  consumption  of  malt  liquors  in  the  United  States  is  thus  estimated 
by  the  Bureau  of  Statistics  of  the  Treasury  Department : 

1897.  1898.  1899. 

Domestic,    in   gallons     .    .  1,066,307,704  1,161,769,114  1,132,723,202 

Imported,              "          .    .          3,002,558  2,457,348  2.797,427 

Total,           "         "          .    .  1,069,310,262  1,164,226,462  1,135^520,629 

Per  capita,  •«•;•««          .    .          14.69  15.64  14.94 


BEER    PRODUCTION    AND    CONSUMPTION    OF    THE    WORLD    FOR    1897    AND    1898. 


Germany 

Production  in  hec 
61,300,000 

-olitres.             Consumption 
115.8  lit 
(Bavaria  235.8 
47.0 
145.0 
44.0 
169.2 
22.4 
4.7 
85.0 
55.0 
40.0 
11.0 
15.3 

Angew.  Chem.,  1899,  p. 

per  capita, 
res. 
) 

868.) 

United  States  (with 
countries) 

South  American 
55,400,000 

55  000  000 

Austria-Hungary 

20,610,000 

Belgium  .        ... 

12,410,000 

France    

8,870,000 

Russia 

4,580,000 

Denmark 

1,980,000 

Switzerland 

1,580,000 

Holland              .    . 

1,485,000 

Sweden    

1,450,000 

Norway  . 

540  000 

Other  countries 

1  1  95  000 

(Zeitsch.  fur 

III.    a.    CONSUMPTION    OF    WINE    IN    THE    UNITED    STATES. 

The  consumption  ot  wine  in  the  United  States,  according  to  the  Bureau 
of  Statistics  of  the  Treasury  Depanment,  has  been  : 

1897.                         1898.  1899. 

Domestic,    in   gallons 33,940,319  17,453,684  22,135,587 

Imported,    "        "    * 4,647,988           3,113,633  3,525,109 

Total,           "        "           38,588,307  20,567,317  26,360,696 

Per  capita,  "        "           0.53                    0.28  0.35 


250 


FERMENTATION   INDUSTRIES. 


III.    b.    WINE    PRODUCTION    OF    THE   WORLD    FOR    1897    AND    1898. 

1897. 

France 32,350.700  hectolitres 

Algeria  and  Tunis     .    .    .  4,457^758 

Italy 25,958,500 

Spain 18,900,000 

Portugal 2,500,000 

Austria-Hungary  ....  3,000,000 

Kussia      2,500,000 

Switzerland 1,250,000 

Germany 2,775,576 

Roumania 3,200,000 

United  States 1,147,000 

Other  countries 10,261,000 

108,300,534          "  119,635,818 


1898. 

litres            32,282,300  hectolitres. 

5,341,000 

31,500,000 

24,750,000 

2,100,000 

2,800,000 

3,120,000 

1,160,000 

1,406,818 

3,900,000 

1,300,000 

9,975,700 

fc 

IV.   a.    PRODUCTION    OF    DISTILLED    SPIRITS    IN    THE  .UNITED    STATES. 


VARIETY  OF  SPIRIT. 

1896. 

1897. 

1898. 

1899. 

Bourbon  whiskey                   .    . 

Gallons. 
16,935,862 

Gallons. 
6,113,726 

Gallons. 
13,439,459 

Gallons. 
17,256,331 

Rye  whiskey                   .... 

9,153,066 

4,269,220 

8,818,240 

10,792,565 

Alcohol                            .... 

9,960,301 

9,503,353 

11,672,795 

11,974,354 

Rum                   .            

1,490,228 

1,294,157 

1,340,547 

1,494,379 

Gin                        

1,098,376 

1,159,314 

1,267,579 

1,266,823 

"High  wines" 

198,299 

206,  739 

174,124 

420,833 

"Neutral  or  cologne  spirit"  . 
Miscellaneous  spirits 

25,564,738 
22,187,833 

16,877,306 
23,041,833 

20,613,205 
23,436,264 

25,876,229 
27,983,051 

Fruit  brandy 

3,403,852 

1,813,427 

2,906,198 

3,097,769 

Total    

89,992,555 

64,279,075 

83,668,411 

100,162,334 

IV.   b.    CONSUMPTION    OF    DISTILLED    SPIRITS    IN    THE    UNITED    STATES. 


1896. 

1897. 

1898. 

1899. 

Domestic  spirits  from  fruit  .  . 
All  other  domestic  spirits  .  .  . 
Imported  for  consumption  .  . 
Total  .  . 

Proof  gallons. 
1,440,810 
68,069,563 
1,541,504 
71,051,877 

Proof  gallons. 
1,146,131 
69,789,991 
2,230,711 
73,166,833 

Proof  gallons. 
1,411,448 
79,159,590 
916,549 

81,487,587 

Proof  gallons. 
1,306,218 
84,614,652 
1,389,358 
87,310,228 

Per  capita  ...... 

1.00 

1.01 

1.10 

1.15 

IV.    C.    PRODUCTION     OF     DIFFERENT     COUNTRIES,    CALCULATED     ON     A     BASIS     OF     PURE 
ALCOHOL    (100   PER    CENT.)    IN    HECTOLITRES. 


COUNTRIES. 

1895. 

1896. 

1897. 

1898. 

1899. 

Germany    

3,333,648 

3,100,505 

3,287,890 

Austria 

1,368  494 

1,397,780 

Hunsrarv 

942,460 

984  301 

Spain  

420,000 

302,000 

Sweden                  .... 

179,870 

184,762 

France        

2,028,022 

2,263,744 

2,533,925 

Holland  

336,000 

337,500 

343,000 

Belgium     

296,551 

KAW  MATERIALS. 


251 


CHAPTER   VII. 


MILK    INDUSTRIES. 

I.  Raw  Materials. 

MILK  is  the  fluid  secreted  by  the  females  of  the  mammalia  for  the 
nourishment  of  their  young,  and  is  therefore  a  food  specially  adapted  for 
the  needs  of  the  animal  organism  at  this  stage,  furnishing  all  the  nutrients 
required  and  furnishing  them  in  the  proper  proportion.  As  will  be  seen 
from  its  analysis,  it  occupies  an  intermediate  position  between  the  cereal 
and  the  strictly  animal  foods,  approximating,  of  course,  more  nearly  the 
latter,  but  showing  in  one  important  constituent,  milk-sugar,  its  relation- 
ship to  the  former. 

Milk  is  a  secretion  of  the  mammary  glands,  in  which  it  is  produced 
proximately  by  certain  processes  of  diffusion  from  the  blood  and  immedi- 
ately by  the  breaking  down  of  the  gland-cells  themselves,  so  that  milk  is 
described  as  cell-material  liquefied.  The  milk  of  all  mammalia  is  essen- 
tially the  same  in  its  constituents,  although  these  vary  somewhat  in  their 
relative  proportions. 

The  essential  constituents  of  milk  are  water,  fat,  casein,  albumen,  milk- 
sugar,  and  salts.  The  relative  proportion  of  these  constituents  in  the  milk 
of  different  animals  may  be  seen  from  the  following  table  of  analyses  from 
Wynter  Blyth :  * 


Fat. 

Casein. 

Albu- 
men. 

Milk- 
sugar. 

Ash. 

Total 
solids. 

Water. 

2.90 

2.40 

0.57 

5.87 

0.16 

12.00 

88.00 

Cow's  milk 

3  50 

3  98 

0.77 

4.00 

0.17 

13.13 

86.87 

Camel's  milk  

2.90 

/•*• 
3. 

•—  \ 
84 

5.66 

0.66 

13.06 

86.94 

Goat's  milk 

420 

v_ 

300 

,  —  ' 
0  62 

400 

056 

12.46 

87.54 

Ass's  milk                      . 

1  02 

1  09 

0  70 

550 

0.42 

8-83 

91.17 

Mare's  milk   
Sheep's  milk  .       .... 

2.50 
5.30 

2.19 
6.10 

0.42 
1  00 

5.50 
4.20 

0.50 
1.00 

11.20 
17-73 

88.80 
82.27 

In  taking  up  milk  as  a  raw  material  for  industrial  utilization,  we  shall 
refer  to  cow's  milk  exclusively  unless  otherwise  specified. 

The  fat  exists  in  the  milk  in  the  form  of  minute  globules  suspended  in  a 
thin  liquid,  forming  for  the  time  a  perfect  emulsion  with  the  aqueous  solu- 
tion of  the  other  constituents.  The  fat  is  essentially  an  intimate  mixture 
of  the  glycerides  of  the  fatty  acids,  palmitic,  stearic,  and  oleic,  not  soluble 
in  water,  and  of  the  glycerides  of  certain  soluble  volatile  fatty  acids,  such 
as  butyric,  caproic,  caprylic,  and  capric. 

The  casein  of  milk  exists  apparently  in  the  fresh  milk  as  a  soluble  com- 

*  Foods,  Composition  and  Analysis,  1882,  pp.  214,  etc. 


252  MILK  INDUSTRIES. 

pound  of  albumen  and  calcium  phosphate,  which  by  the  action  of.  rennet  (a 
ferment  from  the  calf's  stomach)  is  converted  into  the  insoluble  one  known 
as  casein.  The  casein  precipitated  by  rennet  contains  five  to  eight  per  cent, 
of  ash,  consisting  almost  entirely  of  calcium  phosphate.  If,  however,  this 
calcium  phosphate  compound  of  albumen  is  decomposed  by  mineral  acids 
or  acetic  acid,  the  casein  precipitated  contains  only  traces  of  ash.  Lactic 
acid  gives  the  same  result,  so  that  the  casein  coagulated  by  the  souring  of 
the  milk  shows  less  ash  than  that  precipitated  by  rennet  from  sweet  milk. 
On  the  other  hand,  carbon  dioxide  will  act  like  rennet.  The  soluble  com- 
pound existing  in  the  fresh  milk  is  considered  to  be  that  of  the  tricalcium 
phosphate  with  albumen,  while  the  insoluble  one  precipitated  by  rennet  is 
the  acid  calcium  phosphate  with  albumen.  Pure  casein  is  a  perfectly  white 
brittle  crumbling  substance,  insoluble  in  water,  but  soluble  in  very  dilute 
acids  or  very  dilute  alkalies.  In  the  action  of  rennet  and  acids  upon  casein 
a  portion  is  apparently  altered  into  what  are  called  peptones  (lacto-protein 
or  lacto-peptone)  and  remains  dissolved  in  the  whey  of  the  milk.  The  albu- 
men (or  soluble  nitrogenous  matter)  of  milk  seems  to  be  analogous  to  the 
albumen  of  blood.  It  may  be  obtained  by  precipitation  with  basic  acetate 
of  lead  or  by  dialysis  as  a  yellowish  flaky  mass.  The  proportion  of  albumen 
in  milk  is  always,  according  to  Wynter  Blyth,  about  one-fifth  of  the  casein. 

Two  additional  nitrogenous  compounds  have  been  found  by  Blyth  to 
exist  in  small  amounts  in  milk,  to  which  the  names  galactine  and  lacto-chrome 
have  been  given. 

Milk-sugar,  which  is  an  important  and  characteristic  constituent  of  the 
milk,  is  obtained  from  the  serum,  or  "  whey."  After  the  separation  of  the 
curd  has  been  effected  by  the  addition  of  rennet  the  whey  is  evaporated 
on  the  water-bath,  and  yields  the  milk-sugar  in  hard  crystals.  These 
when  purified  by  animal  charcoal  and  recrystallized  show  the  composition 
C12H22O11  +  H2O.  It  is  easily  distinguished  from  other  sugars  of  the  same 
formula.  It  is  converted  by  boiling  with  dilute  acids  into  dextrose  and 
galactose,  which  latter  has  one-fifth  less  copper-reducing  power  than  dex- 
trose. It  undergoes  the  lactic  fermentation  readily  but  the  alcoholic  with 
some  difficulty. 

The  ash  of  milk  consists  of  calcium  citrate  and  the  phosphates  and 
chlorides  of  potassium,  sodium,  calcium,  and  magnesium,  the  salts  that  are 
specially  needed  for  the  growth  of  the  bone-material  in  the  young  nour- 
ished by  the  milk. 

Cow's  milk  is  a  white  or  yellowish-white  liquid,  nearly  opaque,  except 
in  very  thin  layers,  when  it  has  a  bluish  opalescent  appearance,  and  a  specific 
gravity  of  from  1.029  to  1.035.  It  has  a  mild  sweetish  taste  and  a  s  ight 
but  characteristic  odor,  stronger  when  still  warm  from  the  cow.  Upon 
allowing  milk  to  remain  at  rest  for  some  time  it  undergoes  two  changes  : 
First,  a  yellowish- white  layer  forms  on  the  surface  known  as  "  cream,"  due 
to  the  rising  of  the  specifically  lighter  fat-globules  from  the  body  of  the 
liquid  where  they  were  held  back  in  emulsion  with  the  aqueous  liquid ;  and, 
second,  the  aqueous  liquid  after  a  time  undergoes  further  separation  into  a 
thick  coagulum  or  "  curd"  of  casein  and  a  thinner  liquid  or  "  whey,"  holding 
the  sugar  of  milk,  any  lactic  acid  formed  from  it,  and  the  salts  in  solution. 
Both  of  the  changes  are  of  the  greatest  importance,  as  upon  them  are  based 
the  great  milk  industries,  butter-making  and  cheese-making  respectively. 

The  rising  of  the  cream  is  largely  dependent  ordinarily  upon  two  condi- 
tions :  First,  the  temperature, — a  low  temperature  being  favorable  to  the 


PROCESSES  OF  MANUFACTURE. 


253 


separation  ;  and,  second,  complete  freedom  from  agitation.  These  conditions 
are  not,  however,  indispensable,  as  will  be  seen  later  (see  p.  255)  in  speaking 
of  the  use  of  centrifugals  for  the  separation  of  cream. 

The  rising  of  the  cream  is  generally  allowed  to  be  an  entirely  spontaneous 
change  on  the  part  of  the  milk  and  the  first  one  which  it  undergoes,  but  in 
some  creameries  a  little  sour  milk  (containing  lactic  acid)  is  added  to  the 
fresh  milk,  when  first  put  in  the  cream-rising  pans,  so  that  the  curdling  of 
the  casein  may  facilitate  the  escape  of  the  fat-globules  and  the  rising  of  the 
cream.  In  such  a  case  what  remains  on  removal  of  the  cream  is  not  ordi- 
nary skimmed  milk,  but  a  sour  curdled  milk.  The  second  change  men- 
tioned, that  of  curdling,  is  really  preceded  by  a  change  of  some  of  the 
milk-sugar  into  lactic  acid  (due  to  lactic  fermentation,  which  sets  in  very 
quickly  in  hot  weather  or  if  the  milk  has  not  been  kept  in  clean  vessels). 
This  souring  of  the  milk  may  be  retarded  by  the  addition  of  a  little  car- 
bonate of  soda  or  boric  acid.  The  lactic  acid  as  soon  as  liberated  decom- 
poses the  soluble  casein  compound,  before  referred  to  (see  p.  252),  and  the 
casein  is  thrown  out  or  coagulated  as  "curd."  The  separation  of  the  curd 
is  aided  by  heat.  The  liquor  in  which  this  coagulated  casein  floats,  the 
serum  of  milk,  or  "  whey/'  contains  about  one-fourth  of  the  nitrogenous 
matter  of  the  milk,  all  of  its  sugar,  and  most  of  its  mineral  matter.  The 
whey  is  "  sour  whey"  in  case  lactic  acid  has  formed  as  the  antecedent  of  the 
coagulation,  or  "  sweet  whey"  in  case  the  casein  is  thrown  out  by  the  action 
of  rennet  without  the  formation  of  lactic  acid. 

The  composition  of  the  several  parts  into  which  the  milk  is  divided  by 
these  changes  is  thus  given  by  Fleischmann : 


Water. 

Fat. 

Casein. 

Albumen. 

Milk-sugar. 

Ash. 

Whole  milk  

87.60 

3.98 

3.02 

0.40 

4.30 

0.70 

Cream 

77  30 

15  45 

3  20 

0  20 

3  15 

0  70 

Skim-milk 

90  34 

1  00 

2  87 

0  45 

4  63 

0  71 

Butter 

14  89 

8202 

1  97 

028 

028 

0  56 

Buttermilk     .    .    . 

91  00 

080 

3  50 

0.20 

3.80 

070 

Curd    ........ 

59  30 

6  43 

2422 

3.53 

5.01 

1.51 

Whev  

94.00 

035 

0.40 

0.40 

4.55 

0.60 

And  the  relative  yield  of  these  several  constituents  from  one  hundred 
parts  of  milk  is  thus  given  by  the  same  author : 


100  parts  of  sweet  milk  will  yield  (by  natural  cream-raising  or  by  centrifugal 
cream-separating) 


20  parts  of  cream,  which 

(churned  into  butter) 

will  yield 


3.56  parts 
butter. 


79.70  parts  of  skimmed  milk,  which  0.30  parts 

(coagulated  by  rennet  or  acids)  loss, 

will  yield 


16.30  parts 
buttermilk. 


0.14 


7.93  parts 
curd. 


71.45  parts 
whey. 


0.32  loss.        0.30  loss. 


n.  Processes  of  Manufacture. 

1.  MANUFACTURE  OF  CONDENSED  AND  PRESERVED  MILK. — Con- 
densed milk  is  milk  from  which  a  large  portion  of  the  water  originally 
present  has  been  driven  off,  increasing,  of  course,  in  a  proportionate  degree 
the  percentage  of  the  other  constituents.  This  condensed  product  may  or 
may  not  have  cane-sugar  added  to  it  as  a  preservative.  That  to  be  pre- 


254  MILK  INDUSTRIES. 

served  with  cane-sugar  is  made  much  more  concentrated,  and  is  that  which 
is  manufactured  for  export  and  preservation  in  sealed  tin  cans.  In  its 
preparation,  the  milk  is  first  heated  to  65.6°  to  80°  C.  (150°  to  175°  F.)  by 
placing  the  cans  containing  the  milk  in  hot  water,  and  is  then  strained  and 
conveyed  to  the  evaporating  vessels,  which  are  usually  vacuum-pans.  Re- 
fined sugar  is  added  during  the  boiling  to  the  amount  of  one  to  one  and  a 
half  pounds  for  every  quart  of  the  condensed  milk  produced.  The  product 
is  drawn  off  into  cans,  cooled  to  about  70°  F.,  and  then  weighed  into  tins, 
which  are  at  once  soldered  down. 

Condensed  milk  free  from  cane-sugar  is  only  concentrated  to  about  one- 
half  the  degree  attained  in  the  other  product,  and  is  then  cooled  and  filled 
into  stone  or  glass  flasks  provided  with  ordinary  air-tight  stoppers.  It 
will  remain  fresh  for  from  one  to  two  weeks,  and  requires  only  to  be 
diluted  with  its  own  bulk  of  water  in  order  to  yield  the  counterpart  of  the 
original  milk. 

Preserved  milk  is  either  prepared  by  Appert's  process,  which  consists 
in  boiling  the  milk  to  destroy  ferments  and  keeping  it  then  in  hermetically- 
sealed  vessels,  or  by  Scherff's  improved  process,  whereby  the  milk  is  filled 
into  glass  bottles  which  are  stopped  with  corks  previously  steamed  and  then 
fastened  in  by  clamps,  and  then  heated  in  closed  boilers  under  a  pressure  of 
from  two  to  four  atmospheres  to  about  120°  C.  The  bottles  are  then  taken 
out  of  the  pressure-vessel  and  cooled  down,  with  the  corks  covered  with 
flannel  soaked  in  paraffine,  so  that  as  they  cool  the  air  entering  through  the 
pores  of  the  corks  shall  be  filtered.  When  cooled  down,  the  cork,  which 
has  been  drawn  into  the  neck  of  the  bottle  considerably,  is  covered  with  a 
layer  of  paraffine.  This  kind  of  preserved  milk  is  used  largely  in  Germany 
for  invalids  and  children. 

2.  OF  BUTTER. — The  first  operation  in  this  connection  is  the  separation 
as  completely  as  possible  of  the  cream  from  the  rest  of  the  milk.  This  is 
generally  a  spontaneous  process,  it  is  true,  but  its  completeness  is  dependent 
largely  upon  the  conditions  before  referred  to.  There  are  various  ways  in 
which  the  raising  of  the  cream  is  allowed  to  take  place.  We  may  mention 
the  Holstein  process,  in  which  the  fresh  milk  is  at  once  set  to  raise  cream 
in  wide  shallow  pans  at  a  temperature  of  12°  to  15°  C.  (53.6°  to  59°  F.), 
the  Dutch  process,  in  which  it  is  first  rapidly  cooled  down  in  large  vessels 
immersed  in  cold  water  to  about  15°  C.  (59°  F.)  and  then  transferred  to 
the  shallow  pans  for  the  raising  of  the  cream,  and  the  Schwartz  process, 
largely  used  in  Northern  Europe,  which  differs  from  the  Dutch  process 
chiefly  in  using  much  deeper  pans  at  a  lower  temperature,  4.4°  to  10°  C. 
(40°  to  50°  F.).  Very  similar  to  this  last  mentioned  are  the  Hardin  and 
the  Cooley  methods,  which  also  use  deep  cream-raising  pans.  In  the  former 
of  these,  ice  and  not  ice-water  is  used  to  effect  the  cooling,  the  pans  being 
exposed  to  the  influence  of  air  cooled  by  ice,  the  claim  being  made  that  the 
cream  is  obtained  in  more  solid  condition.  In  the  Cooley  method,  used 
largely  in  this  country,  the  water  not  only  surrounds  the  can  outside  as 
high  as  the  milk  inside,  but  is  made  to  rise  an  inch  or  two  above  the  lid,  so 
that  the  can  is  completely  submerged  and  all  contamination  from  external 
sources  prevented. 

The  processes  which  use  shallow  pans  give  a  larger  yield  of  cream  but 
take  a  longer  time  (thirty-six  to  forty-eight  hours  as  against  eighteen  to 
twenty-four  for  those  using  deep  pans).  Within  the  last  ten  years  the 
principle  of  the  centrifugal  has  been  applied  to  the  separation  of  the  cream 


PROCESSES  OF  MANUFACTURE. 


255 


FIG.  74. 


from  the  milk,  and  this  has  proven  itself  so  successful  that  in  most  large 
creameries  it  is  now  utilized.  The  milk  is  placed  in  a  horizontal  rotating 
vessel  driven  at  a  high  rate  of  speed,  which  causes  the  heavier  milk  fluid 
to  gravitate  towards  the  circumference  of  the  vessel,  whilst  the  cream  re- 
mains nearer  the  centre  and  rises  towards  the  upper  part  of  the  rotating 
bowl,  whence  it  is  removed  by  a  conveniently-placed  aperture  on  the  side 
of  the  vessel.  An  exit  is  also  provided  for  the  gradual  removal  of  the 
skimmed  milk,  thus  making  room  for  fresh  milk  to  be  added  ~to  the  ap- 
paratus and  allowing  the  process  to  be  carried  on  continuously.  Figs.  74 

and  75  show  the  Laval  cream 
separator  in  general  view  and  in 
section.  The  fresh  milk  is  ad- 
mitted through  a  funnel,  the 
tube  of  which  is  prolonged  so 
as  to  deliver  the  milk  near  the 
bottom  of  the  revolving  drum. 
The  skim-milk  flows  out  through 
an  opening,  £,  and  the  cream 
through  a  higher  opening,  the 
relative  position  of  which  can  be 
changed  by  an  adjustable  screw 
above.  The  cream  obtained  by 
these  centrifugal  separators  seems 

FIG.  75. 


to  be  freer  from  mechanically-enclosed  casein  than  that  gotten  in  any  of 
the  old  separation  processes,  as  is  seen  in  the  appended  cream  analyses  by 
Bell,*  where  samples  2  and  6  were  separated  by  the  centrifugal  separator : 


Water. 

Fat. 

Milk- 
sugar. 

Casein. 

Ash. 

1. 

5402 

39  40 

1.85 

3.76 

0  57 

2. 

60.66 

33.60 

2.43 

2.90 

0.41 

8 

Raw  cream     .    .        .... 

67  93 

2444 

2  96 

4  04 

0  63 

4 

Raw  cream     .... 

58  07 

35  67 

2  20 

3  55 

0  51 

5. 

6307 

30  74 

2  61 

304 

0  54 

6. 

Thick  cream  

37  62 

58  77 

1  46 

1  83 

032 

7 

Devonshire  clotted  cream 

33  76 

59  79 

1  01 

4  97 

0  47 

_i 

*  Analysis  and  Adulteration  of  Food,  p.  35. 


256 


MILK  INDUSTRIES. 


The  composition  of  the  skimmed  milk  of  course  varies  according  to  the 
extent  to  which  the  cream  has  been  removed.  The  following  analyses  by 
Voelcker  represent  its  average  composition  as  obtained  in  the  ordinary  way 
and  as  obtained  by  the  Laval  separator : 


Water. 

Butter- 
fat. 

Casein. 

Milk- 
sugar. 

Ash. 

89.25 

1.12 

3.69 

5.17 

078 

90.82 

0.31 

3.31 

4.77 

0.79 

The  coalescence  of  the  fat-globules  separated  in  the  cream  layer  is  now 
to  be  effected  to  form  the  compact  butter.  This  is  almost  universally 
accomplished  by  mechanical  agitation  in  the  process  called  churning.  The 
churns  may  be  of  very  diverse  construction,  either  for  hand  or  power. 
The  cream  may  be  taken  as  "  sweet  cream"  freshly  separated  in  the  centrif- 
ugal or  raised  from  deep  pans  where  the  skim-milk  is  still  sweet,  or  it  may 
be  "  sour  cream,"  which  has  stood  longer  and  has  separated  slowly  in  shal- 
low pans.  The  sour  cream  is  more  easily  churned,  but  the  butter  will  con- 
tain more  casein,  while  sweet  cream  yields  a  butter  with  pleasanter  taste 
and  better  keeping  qualities  because  containing  less  casein.  The  tempera- 
ture most  favorable  for  churning  is  about  15.5°  C.  (60°  F.).  Sometimes 
cream  is  heated  to  a  much  higher  temperature  first,  and  then  cooled  down 
to  60°  F.  before  being  churned.  Butter  thus  made  keeps  well. 

Butter  has  almost  invariably  some  salt  added  to  it  even  when  for  im- 
mediate consumption ;  the  quantity  in  this  case  need  not  be  large  (five-tenths 
to  two  per  cent.),  but  when  it  is  to  be  packed  for  preservation  or  for  export 
considerably  more  is  added,  so  that  it  is  known  as  "  salt  butter."  Export 
butter  has  also  a  small  addition  of  sugar,  and  sometimes  saltpetre,  added,  as 
well  as  salt,  to  preserve  it.  Genuine  butter  will  always  have  a  yellowish 
color,  which,  however,  becomes  deeper  in  summer  when  the  cows  have  an 
abundance  of  fresh  pasture.  Most  butter  manufacturers  now  add  a  little 
vegetable  coloring  matter  like  annato,  carrot-color,  or  saffron,  to  give  the 
butter  this  desired  yellow  tint  in  winter,  when  the  butter  would  otherwise 
be  very  much  lighter  in  color.  All  butter  will  in  time  become  rancid  and 
take  a  strong  disagreeable  odor.  This  is  due  to  the  gradual  spontaneous 
decomposition  of  the  butyric  ether  under  the  influence  of  air  and  light 
whereby  free  butyric  acid  is  liberated. 

The  composition  of  butter  will  be  more  fully  spoken  of  later  on  in  dis- 
cussing the  products  of  these  industries. 

3.  OF  ARTIFICIAL  BUTTER  (Butterine,  Oleomargarine). — The  manu- 
facture of  substitutes  for  normal  dairy  butter  began  with  the  experiments 
of  the  Frenchman  Mege-Mouries  in  1870.  He  found  that  carefully- 
washed  beef-suet  furnished  a  basis  for  the  manufacture  of  an  excellent 
substitute  for  natural  butter.  The  thoroughly-washed  and  finely-chopped 
suet  was  rendered  in  a  steam-heated  tank,  taking  for  one  thousand  parts  of 
fat,  three  hundred  parts  of  water,  one  part  of  carbonate  of  potash,  and 
two  stomachs  of  pigs  or  sheep.  The  temperature  of  the  mixture  was  raised 
to  45°  C.  After  two  hours,  under  the  influence  of  the  pepsin  in  the 
stomachs,  the  membranes  are  dissolved  and  the  fat  melted  and  risen  to  the 
top  of  the  mixture.  After  adding  a  little  salt,  the  melted  fat  is  drawn  off, 


PROCESSES  OF  MANUFACTURE.  257 

stood  to  cool  so  as  to  allow  the  stearin  and  palmitin  to  crystalline  out, 
and  then  pressed  in  bags  in  a  hydraulic  press.  Forty  to  fifty  per  cent,  of 
solid  stearin  remains,  while  fifty  to  sixty  per  cent,  of  fluid  oleopalmitin 
(so-called  "  oleomargarine")  is  pressed  out.  Mege  then  mixed  the  "  oleo 
oil"  with  ten  per  cent,  of  its  weight  of  milk  and  a  little  butter-color  and 
churned  it.  The  fat-cutting  process  of  M^ge-Mouries  is  shown  in  Fig.  76 

FIG.  76. 


and  the  churning  of  the  "  oleo  oil"  in  Fig.  77.  The  product  was  then 
worked,  salted,  and  constituted  the  "  oleomargarine,"  or  butter  substitute. 
Various  improvements  have  been  made  in  the  process  of  Mege,  and  it  has 
been  found  that  leaf-lard  can  be  worked  in  the  same  way  as  beef-suet,  and 
will  yield  an  oleopalmitin  suitable  for  churning  up  into  a  butter  substitute. 
The  processes  now  followed  are  given  substantially  as  described  by  Mr. 
Phil.  D.  Armour  in  his  testimony  before  a  committee  of  Congress  :  *  "  The 
fat  is  taken  from  the  cattle  in  the  process  of  slaughtering,  and  after  thorough 
washing  is  placed  in  clean  water  and  surrounded  with  ice,  where  it  is  allowed 
to  remain  until  all  animal  heat  has  been  removed.  It  is  then  cut  into  small 
pieces  by  machinery  and  cooked  at  a  temperature  of  about  150°  F.  (65.6° 
C.)  until  the  fat  in  liquid  form  has  separated  from  the  fibrin  or  tissue,  then 
settled  until  it  is  perfectly  clear.  Then  it  is  drawn  into  graining-vats  and 
allowed  to  stand  for  a  day,  when  it  is  ready  for  the  presses.  The  pressing 
extracts  the  stearin,  leaving  a  product  commercially  known  as  'oleo  oil/ 
which  when  churned  with  cream  or  milk,  or  both,  and  with  usually  a  pro- 
portion of  creamery  butter,  the  whole  being  properly  salted,  gives  the  new 

*  Department  of  Agriculture,  Bulletin  No.  13,  Part  i.  p.  16. 
17 


258 


MILK  INDUSTRIES. 


food  product,  oleomargarine.  In  making  butterine  we  use  'neutral  lard/ 
which  is  made  from  selected  leaf-lard  in  a  very  similar  manner  to  oleo  oil, 
excepting  that  no  stearin  is  extracted.  This  neutral  lard  is  cured  in  salt 
brine  for  forty-eight  to  seventy  hours  at  an  ice-water  temperature.  It  is 


FIG.  77. 


then  taken  and  with  the  desired  proportion  of  oleo  oil  and  fine  butter  is 
churned  with  cream  and  milk,  producing  an  article  which  when  properly 
salted  and  packed  is  ready  for  the  market. 

"  In  both  cases  coloring  matter  is  used,  which  is  the  same  as  that  used 
by  dairymen  to  color  their  butter.  At  certain  seasons  of  the  year — viz.,  in 
cold  weather — a  small  quantity  of  sesame  oil  or  salad  oil  made  from  cotton- 
seed oil  is  used  to  soften  the  texture  of  the  product." 

It  will  be  seen  that  in  this  process  a  higher  temperature  is  used  in  render- 
ing the  fat  than  was  used  originally  by  M£ge.  He  obtained  about  fifty  per 
cent,  of  oleo  oil.  The  manufacturers  now  obtain  sixty-two  per  cent,  or 
more.  The  oleo  oil  from  beef-suet  and  the  neutral  lard  from  leaf-lard  are 
frequently  mixed,  the  proportions  varying  according  to  the  destination  of 
the  product ;  a  warm  climate  calling  for  more  "  oleo,"  a  cold  one  for  more 
"  neutral."  In  ordinary  practice  about  forty-eight  gallons  of  milk  are  used 
for  churning  with  the  oil  per  two  thousand  pounds  of  product.  Plain  oleo- 
margarine is  the  cheapest  product  made.  By  adding  to  the  material  in  the 
agitator  or  churn  more  or  less  pure  butter  what  is  known  as  butterine  is 
produced,  two  grades  of  which  are  commonly  sold, — viz.,  "  creamery  but- 
terine," containing  more,  and  "  dairy  butterine,"  containing  less,  butter. 

Large  quantities  of  oleo  oil  are  now  manufactured  and  exported  as  such 
from  the  United  States  to  Europe,  notably  to  Holland,  where  it  is  made  up 
into  oleomargarine  butter.  There  are  said  to  be  seventy  manufactories  of 
this  kind  in  Holland  which  work  up  oleo  oil  from  all  parts  of  the  world. 

4.  CHEESE-MAKING. — The  manufacture  of  cheese  depends  upon  the 


PROCESSES  OF  MANUFACTURE.  259 

property  possessed  by  casein  of  being  curdled  by  acids  or  ferments.  In  the 
case  of  sour  milk,  the  milk-sugar  has  developed  by  the  lactic  fermentation 
some  lactic  acid,  and  this,  as  before  stated,  promptly  throws  out  the  casein 
in  the  insoluble  form.  In  the  case  of  sweet  milk  we  usually  accomplish  the 
curdling  of  the  casein  not  by  the  use  of  an  acid,  but  with  a  ferment  con- 
tained in  the  preparation  called  rennet.  This  is  prepared  from  the  fourth 
stomach  of  the  calf  by  first  cleansing  the  stomach,  cutting  and_drying  it, 
and  then  leaving  some  brine  in  contact  with  its  lining  membrane  for  a  few 
days.  The  salt  liquid  will  thus  acquire  very  active  properties,  so  that  a 
small  quantity  will  curdle  a  large  quantity  of  milk.  We  would  have  then, 
according  as  one  or  the  other  method  is  followed,  a  sour-milk  cheese  or  a 
sweet-milk  cheese.  The  former  have  a  very  minor  value  commercially,  being 
made  mainly  for  immediate  domestic  consumption.  The  latter  class  include 
all  the  more  valuable  commercial  varieties.  Of  these  we  may  distinguish 
fat,  half-fat  (or  medium),  and  lean  cheeses,  or  as  they  are  also  designated  to 
indicate  their  origin,  cream  cheeses,  whole  milk  cheeses,  and  skim-milk 
cheeses.  As  these  last  names  indicate,  the  material  may  differ.  We  may 
have,  moreover,  all  gradations  or  mixtures  of  cream,  whole  milk,  and  skim- 
milk  used  for  the  various  grades  manufactured. 

In  cheese-making  from  sweet  milk,  the  milk,  whether  whole,  mixed 
with  cream,  or  skimmed,  is  heated  to  about  30°  C.  (86°  F.)  and  the  rennet 
added.  It  curdles  usually  in  from  thirty  to  forty  minutes.  After  the  curd 
has  formed  and  been  cut,  or  "  broken  down/7  the  heat  is  raised  to  98°  F. 
(36°  C.)  to  insure  the  souring  of  the  whey  and  its  more  complete  separation 
from  the  curd.  Or  the  curd  produced  at  not  over  86°  F.  (30°  C.)  is  after 
being  cut  collected  in  a  heap,  covered  with  a  cloth  to  preserve  the  heat,  and 
allowed  to  stand  an  hour  to  develop  the  acidity  which  serves  to  harden  the 
curd  and  promote  its  separation  from  the  whey.  The  curd  is  now  cut  up, 
worked  to  free  it  from  the  whey,  salted  and  pressed.  After  it  has  acquired 
sufficient  coherence  (which  requires  from  twelve  to  fourteen  hours)  it  is  taken 
from  the  press  and  placed  in  the  curing-room  to  "  ripen."  This  ripening 
process  is  essentially  a  fermentative  one,  and  during  its  progress  the  curd 
loses  its  insipidity  and  acquires  the  characteristic  taste  and  flavor  of  cheese. 

In  this  process  of  ripening,  the  milk-sugar  remaining  in  the  cheese  be- 
comes transformed  partly  into  lactic  acid  and  partly  into  alcohol  and  carbon 
dioxide.  In  some  varieties  the  carbon  dioxide  swells  up  ("  huffs")  the  cheese- 
mass  and  gives  it  the  porous  character  so  noticeable  in  the  ripened  cheese. 

Fresh  cheese  has  an  acid  reaction,  but  this  diminishes  more  and  more  in 
the  ripening,  as  the  casein  is  gradually  altered,  soluble  albuminoids,  pep- 
tone-like bodies,  and  organic  bases  like  leucine,  tyrosine,  and  amines  being 
formed. 

Some  cheeses,  especially  the  cream  cheeses,  are  not  pressed,  but  come  on 
the  market  as  soft  cheeses.  In  these  the  curdling  by  rennet  has  also  been 
effected  at  a  lower  temperature  than  in  the  case  of  the  hard  cheeses. 

Cheese  has  also  been  manufactured  extensively  in  this  country  from 
skimmed  milk  to  which  oleomargarine  or  "  oleo  oil"  has  been  added  so  as 
to  give  the  finished  product  the  character  of  a  whole-milk  cheese.  This 
product  is  now  quite  supplanted,  however,  by  the  "  lard  cheese,"  which,  ac- 
cording to  Caldwell,*  was  made  in  1882  at  over  twenty  factories  in  the  State 
of  New  York.  In  this  process  an  emulsion  of  lard  is  made  by  bringing 

*  Second  Annual  Report  New  York  State  Board  of  Health,  p.  529. 


260 


MILK  INDUSTRIES. 


together  in  a  "disintegrator"  lard  and  skimmed  milk  both  previously  heated 
to  140°  F.  in  steam-jacketed  tanks ;  the  "  disintegrator"  consists  of  a  cyl- 
inder revolving  within  a  cylindrical  shell :  the  surface  of  the  cylinder  is 
covered  with  fine  serrated  projections,  each  one  of  which  is  a  tooth  with  a 
sharp  point ;  as  this  cylinder  revolves  rapidly  within  its  shell  the  mixture 
of  melted  lard  and  hot  skimmed  milk  is  forced  up  into  the  narrow  inter- 
space ;  and  the  lard  becomes  very  finely  divided  and  most  intimately  mixed, 
or  "  eniulsionized,"  with  the  milk.  This  emulsion  consists  of  from  two  to 
three  parts  of  milk  to  one  of  lard.  In  making  the  cheese,  a  quantity  of 
this  emulsion,  containing  about  eighty  pounds  of  lard,  is  added  to  six  thou- 
sand pounds  of  skimmed  milk  and  about  six  hundred  pounds  of  butter- 
milk in  the  cheese-vat,  and  the  lard  that  does  not  remain  incorporated  with 
the  milk  or  curd,  usually  about  ten  pounds,  is  carefully  skimmed  off.  These 
quantities  of  the  materials  yield  from  five  hundred  to  six  hundred  pounds 
of  cheese  containing  about  seventy  pounds  of  lard,  or  about  fourteen  per 
cent.  About  one-half  of  the  fat  removed  as  cream  in  the  skimming  of  the 
milk  is  thus  replaced  by  lard.  It  is  claimed  that  no  alkali  or  antiseptic  is 
used,  and  that  only  the  best  kettle-rendered  lard  can  be  employed,  because 
of  the  injurious  effect  of  any  inferior  article  on  the  quality  of  the  cheese, 
and  that  before  even  this  lard  is  used  it  is  deodorized  by  blowing  steam 
under  eighty  pounds  pressure  through  it  for  an  hour.  According  to  many 
witnesses  the  imitation  is  excellent,  for  experts  have  been  unable  to  pick  out 
lard  cheeses  from  a  lot  of  these  and  full-cream  cheeses  of  good  quality 
together. 

HE.  Products. 

1.  CONDENSED  AND  PRESERVED  MILK. — The  distinction  between  con- 
densed milk  prepared  with  the  addition  of  cane-sugar  and  that  prepared 
without  sugar  has  already  been  referred  to  in  speaking  of  the  manufacture 
of  this  class  of  products.  The  first  of  these  classes  forms  a  white  or  yellow- 
ish-white product  of  about  the  consistency  of  honey  and  ranging  in  specific 
gravity  from  1.25  to  1.41.  It  should  be  completely  soluble  in  from  four  to 
five  times  its  bulk  of  water  without  separation  of  any  flocculent  residue, 
and  then  possess  the  taste  of  perfectly  fresh  sweetened  milk. 

The  second  class  of  condensed  milk  preparations,  those  without  addition 
of  cane-sugar,  are  not  boiled  down  to  the  same  degree  and  remain  perfectly 
liquid,  and  are  put  up  therefore  in  glass  bottles  instead  of  being  sealed  in 
cans.  Analyses  of  both  classes  are  given  on  the  authority  of  Battershall.* 


Condensed  Milk  with  Addition  of  Sugar. 


BRAND. 

Water. 

Fat. 

Cane-  and 
milk-sugar. 

Casein. 

Salts. 

Alderney     

30.05 

10.08 

46.01 

12.04 

1.82 

Anglo-Swiss  (American)  .... 
Anglo-Swiss  (English)     .... 
Anglo-Swiss  (Swiss)  

29.46 
27.80 
25.51 

8.11 
8.24 
8.51 

5041 
51.07 

53  27 

10.22 
10.80 
10.71 

1.80 
2.09 
200 

Eagle                   

27.30 

6.60 

44.47 

10.77 

1.86 

29.44 

9.27 

49.26 

10.11 

1.92 

*  Food  Adulteration  and  its  Detection,  p.  53. 


PRODUCTS. 
Condensed  Milk  ivithout  Cane-sugar. 


261 


BRAND. 

Water. 

Fat. 

Milk-sugar. 

Casein. 

Salts. 

American    

52.07 

15.06 

16.97 

14.26 

2.80 

New  York              . 

56  71 

14  13 

13  98 

13  18 

200 

Granulated  Milk  Company     .    . 
Eao-le  " 

55.43 
5601 

13.16 
14.02 

14.84 
14  06 

14.04 
13  9J) 

2.53 
201 

2.  BUTTER  AND  BUTTER  SUBSTITUTES. — Commercial  butter  is  more 
or  less  granular,  and  the  more  perfect  the  granular  condition  the  higher  is 
its  quality  considered.  Special  effort  has  been  made  in  the  case  of  oleo- 
margarine or  butterine  to  imitate  this  granulation,  as  the  artificial  product 
does  not  naturally  tend  to  show  such  appearance.  A  good  butter  when  fresh 
has  a  pleasant  fragrant  odor  and  agreeable  taste,  but  the  flavor,  like  the 
color,  varies  with  the  food  of  the  cow,  certain  plants,  like  garlic,  giving  a  quite 
pronounced  flavor  to  both  milk  and  butter.  At  ordinary  temperatures  but- 
ter is  easily  cut  or  moulded,  and  it  readily  melts  to  a  transparent,  light- 
colored  oil.  It  always  contains,  according  to  the  thoroughness  with  which 
it  has  been  kneaded  and  washed,  more  or  less  casein,  which  is  very  liable  to 
undergo  decomposition,  and  hence  the  necessity  for  the  addition  of  larger  or 
smaller  amounts  of  salt,  which  acts  as  a  preservative.  When  the  butter-fat 
is  freed  from  curd  and  water  by  melting  the  butter  and  drawing  off  the  oily 
layer  it  may  be  kept  for  a  long  time  without  change. 

This  butter-fat  is  made  up,  as  was  stated  in  speaking  of  the  fat  of  milk, 
of  the  glycerides  of  oleic,  palmitic,  and  stearic  acids  (the  so-called  insoluble 
acids)  and  the  glycerides  of  butyric,  caproic,  caprylic,  and  capric  acids  (the 
so-called  soluble  acids).  The  proportion  in  which  they  exist  in  butter-fat 
varies  within  very  slight  limits  only,  so  that  five  to  six  per  cent,  may  be 
called  the  average  percentage  of  the  soluble  acids,  and  eighty-eight  per  cent, 
the  average  percentage  of  the  insoluble  acids  present  in  butter-fat.  This 
gives  a  very  important  means  of  distinguishing  between  a  natural  butter  and 
oleomargarine  or  natural  butter  adulterated  with  the  imitations.  In  such 
butter  the  glycerides  of  the  soluble  acids  (butyric,  etc.)  are  either  wanting 
entirely  or,  if  a  little  cream  was  used  in  the  churning  with  "  oleo  oil"  present, 
in  very  much  smaller  amount  than  the  normal.  This  distinction  will  be  evi- 
dent from  the  analyses  of  normal  butter  and  oleomargarine  butters,  given  on 
the  authority  of  Dr.  Bell.* 


Genuine  Butter,  showing  Range  of  Variation  in  Composition  of  the  Fat. 


Water. 

Salt. 

Curd. 

Butter- 
fat. 

Specific 
gravity  at 
100°  F. 

Percentage  of 
fixed  acids  in 
fat. 

Percentage  of 
soluble  acids 
as  butyric. 

Melting 
point, 
Fahren- 
heit. 

1. 

7.55 

1.03 

1.15 

90.27 

913.89 

85.56 

7.41 

80°  F. 

2. 

11.71 

3.60 

0.95 

83.74 

911.45 

88.24 

5.41 

90°  F. 

3. 

11.42 

1.29 

1.12 

86.17 

910.47 

88.53 

4.84 

90°  F. 

4. 

12  55 

089 

0.74 

85.82 

910.20 

89.00 

4.57 

90°  F. 

5. 

14.62 

1.48 

1.88 

8202 

910.70 

89.00 

4.50 

91°  F. 

*  Analysis  and  Adulteration  of  Foods,  pp.  68  and  70. 


262 


MILK  INDUSTRIES. 


Analyses  of  Oleomargarine  Butter  or  Butterine. 


Water. 

Salt. 

Curd. 

Fat. 

Specific 
gravity  at 

Percentage 
of  fixed 

.Percentage 
of  soluble 

Melting 
point.  Fah- 

100° F. 

acids. 

acids. 

renheit. 

14.30 

3.81 

0.48 

81.41 

903.84 

94.34 

82°  F. 

11.21 

1.70 

1.73 

85.36 

902.34 

94.83 

0.66 

78°  F. 

12.33 

400 

1.09 

82.58 

903.15 

95.04 

0.47 

79°  F. 

5.32 

1.09 

0.67 

9292 

903.79 

96.29 

0.23 

81°  F. 

13.21 

3.99 

1.07 

81.73 

901.36 

95.60 

0.16 

78°  F. 

The  best  grades  of  artificial  butter  do  not  differ  in  appearance  from 
ordinary  butter.  To  induce  the  proper  granulation  of  the  oleomargarine,  it 
is  chilled  thoroughly  with  fragments  of  ice  immediately  after  it  is  taken 
from  the  churn  and  before  kneading  or  salting  it.  In  color,  consistence, 
and  taste  it  may  be  made  to  imitate  the  natural  butter  so  as  to  deceive  most 
persons.  A  distinction,  it  is  said,  however,  can  always  be  noted  in  the  taste 
when  it  is  melted  upon  hot  boiled  potatoes,  to  which  it  imparts  a  peculiar 
taste  recognizable  as  distinct  from  that  of  a  true  butter. 

3.  CHEESE. — The  general  classification  of  the  cheeses  has  been  given  in 
speaking  of  the  methods  of  manufacture,  and  the  distinction  between  the  fat 
and  lean  cheeses,  between  cream  cheese,  whole-milk  and  skimmed-milk 
cheeses  given.  The  terms  hard  and  soft  cheeses  are  applied  according  as 
the  curd  has  or  has  not  been  pressed  in  the  process  of  manufacturing. 
Most  of  the  names  which  have  been  attached  to  the  different  varieties  of 
cheese  are  those  of  localities.  We  will  indicate  the  character  of  a  few  of 
these. 

Neufchatel  cheese  is  a  Swiss  cream  cheese. 

Limburger  cheese  is  a  soft  fat  cheese. 

Fromage  de  Brie  is  a  soft  French  cheese  rapidly  ripening  and  devel- 
oping ammoniacal  compounds. 

Camembert  cheese  is  also  a  cream  cheese. 

Roquefort  cheese  is  a  cheese  made  from  the  milk  of  the  ewe. 

Gruy£re  cheese  is  a  peculiarly  flavored  Swiss  cheese. 

Cheddar  cheese  is  a  hard  cheese  made  with  whole  milk. 

Single  and  double  Gloucester  are  made,  the  first  from  a  mixture  of 
skimmed  and  entire  milk,  and  the  second  from  the  entire  milk. 

Parmesan  cheese  is  a  very  dry  cheese,  with  a  large  amount  of  casein 
and  only  a  moderate  percentage  of  fat. 

Eidam  cheese  is  a  Dutch  cheese,  also  relatively  dry,  and  covered  with 
red  coloring. 

In  illustration  of  the  chemical  composition  of  these  different  varieties 
of  cheese  we  will  append  three  tables,  the  first  of  analyses  from  miscellane- 
ous sources,  and  the  second  and  third  from  Bell,*  giving  a  fuller  study  of 
the  composition  of  the  cheeses  and  showing  the  difference  between  the  fat 
normally  belonging  to  the  cheese  and  the  fat  added  in  the  shape  of  lard  or 
"  oleo  oil"  in  adulterated  cheeses. 


*  Analysis  and  Adulteration  of  Foods,  pp.  79  and  82. 


PRODUCTS. 


263 


Water. 

Fat. 

Casein. 

Non-nitro- 
genous 
and  loss. 

Ash. 

Neufchatel  (Fleischmann)       

34.50 
36.10 
35.70 
51.87 
51.30 
27.56 

41.90 
29.50 
34.20 
24.83 
21.50 
15.95 

13.00 
28.00 
24.20 
18.30 
19.00 
44.08 

7.00 
3.30 
3.00 

3.60 
3.10 
2.90 
5.00 
4.70 
5.72 

Emmenthaler  (Fleischmann) 

Limburger  (Fleischmann)  
Brie  (Wynter  Blyth) 

Camembert  (Wvnter  Blyth) 

Parmesan  (Wynter  Blyth) 

100  PARTS  CONTAIN 

Proportion  of  fat  in 
100  parts  of  dry 
cheese. 

Proportion  of  fat 
in  100  parts  of 
casein  and  fat. 

Salt  percentage  in 
cheese. 

PERCENTAGE 
COMPOSITION 
OF  THE  FAT. 

« 

1 

a 

Free  acid 
as  lactic. 

4 

y> 

I1 

r2 
|l 

Stilton 

23.57 

28.63 
31.55 
32.26 
31.85 

35.60 
33.66 
37.11 
35.75 
41.30 

39.13 
38.24 
35.93 
34.38 
34.34 

31.57 
30.69 
30.68 
28.35 
22.78 

32.55 
29.64 
28.83 
27.16 

27.88 

28.16 
30.67 
26.93 
31.10 
28.25 

1.24 

6.27 
1.32 
1.35 

0.45 
0.27 
0.86 
0.31 
0.57 

3.51 
3.49 
3.42 

4.88 
4.58 

4.22 
4.71 
4.42 
4.49 
7.10 

5119 
53.57 
52.49 
50.75 
49.02 

46.26 
48.78 
48.78 
44.12 
38.80 

52.50 
54.12 
53.34 
54.24 
53.08 

50.49 
47.02 
50.84 
45.24 
42.41 

0.67 
0.72 
0.82 
3.04 
2.11 

1.43 
0.81 
1.69 
1.28 
4.45 

4.42 
4.26 
4.81 
4.91 
4.40 

4.55 
4.41 
5.55 
6.68 
5.84 

88.96 
89.06 
88.49 
88.70 
89.18 

8875 
88.97 
87.76 
86.89 
87.58 

American  (red) 
American  (pale) 
Roquefort   .  .  . 
Gorgonzola    .  . 
Cheddar     (medi 
urn)    

Gruyere 

Cheshire 

Single  Gloucester 
Dutch  (Eidam)  .  . 

Analyses  of  Oleomargarine  and  Lard  Cheeses. 


100  PARTS  CONTAIN 

Per 
cent,  of 
salt. 

100  PARTS  OF 
FAT  CONTAIN 

Melting  point 
of  fat. 

Water. 

Fat. 

Casein 
and 
free 
acids. 

Ash. 

Insol- 
uble 
acids. 

Soluble 
acids. 

Oleomargarine  cheese  .  . 
Lard  cheese    

30.95 
31.30 

28.80 
24.66 

36.27 
38.87 

3.98 
5.17 

1.14 
1.55 

92.43 
92.88 

2.16 
1.55 

77°  F.  (25°  C.). 
92°  F.  (33.3°  C.). 

4.  MILK-SUGAR. — The  manufacture  of  crystallized  milk-sugar  (lactose) 
has  developed  greatly  in  recent  years,  and  a  perfectly  white,  well-crys- 
tallized product  is  now  obtained.  For  its  preparation,  the  sweet  skim- 
milk  as  it  comes  from  the  cream  separator  is  precipitated  with  acetic  acid, 
filtered,  and  boiled  either  in  open  steam-heated  evaporators  or  in  vacuum 
pans.  This  first  boiling  should  take  several  hours.  The  whey  during  the 
boiling  becomes  more  cloudy,  but  suddenly  clears,  and  the  remaining 
albuminoids  will  separate  in  large  flocks  that  can  readily  be  filtered.  It  is 
to  be  filtered  hot  and  boiled  to  crystallization  in  a  vacuum  pan.  The  raw 
sugar  so  obtained  can  be  refined  and  made  white  exactly  as  described  under 
cane-sugar.  As  the  first  crystallization  is  all  that  can  be  brought  to  satis- 
factory color  and  purity,  the  yield  is  not  much  over  ten  per  cent,  of  the 
total  sugar  contained  in  the  milk. 


264 


MILK  INDUSTRIES. 


5.  KOUMISS. — Kounrss  is  an  alcoholic  drink  made  by  the  fermentation 
of  milk.  As  made  by  the  fermentation  of  mare's  milk  it  has  long  been  a 
favorite  beverage  with  the  Tartars  and  other  Asiatic  tribes.  Cow's  milk 
has  been  used  chiefly  in  making  it  in  both  Europe  and  America.  Mare's 
milk  is  the  more  suitable  for  fermentation  because  of  the  larger  percentage 
of  milk-sugar  which  it  contains. 

The  fermentation  is  started  by  mixing  fresh  milk  with  some  already 
soured.  Both  the  lactic  and  the  alcohol  fermentations  are  set  up,  with  the 
production  of  lactic  acid,  alcohol,  and  carbonic  acid  gas.  Some  of  the  albu- 
minoids are  also  changed  into  peptones.  The  composition  of  the  koumiss 
as  prepared  from  both  mare's  and  cow's  milk  is  shown  in  the  accompanying 
analyses  from  various  sources  : 


o> 
"3 
£ 

*§ 

g. 

•12 
& 

Albumi- 
noids. 

I 

Alcohol. 

Carbon 
dioxide. 

a 

< 

Koumiss  from  mare's  milk  (Fleischmann)  .... 
Koumiss  from  cow's  milk  (Fleischmann)  .... 
Koumiss  from  mare's  milk  (Konig) 

91.53 

8893 
9247 

1.25 
3.11 
1  24 

1.01 
079 
091 

1.91 
2.03 
197 

1.27 
085 
126 

1.85 
2.65 
1  84 

0.88 
1.03 
095 

0.29 
0.44 

Koumiss  from  mare's  milk  (London,  1884)  .... 
Koumiss  from  co*v's  milk  (Wiley) 

91.87 
8932 

0.79 
438 

1.04 
047 

1.91 
2  56 

1.19 

208 

2.86 
076 

083 

6.  KEPHIR. — This  is  a  Caucasian  product  somewhat  similar  to  koumiss, 
but  prepared  from  cow's  milk  in  leathern  bottles  by  the  aid  of  a  peculiar 
ferment  known  as  "  kephir  grains."  According  to  Kern,  as  quoted  by 
Allen  (Commercial  Organic  Analysis,  2d  ed.,  vol.  iv.  p.  242),  the  kephir 
ferment  is  an  elastic  cauliflower-like  mass  found  below  the  snow  line  on 
certain  bushes.  The  fungus  consists  of  bacilli  and  yeast-cells,  each  cell 
containing  two  round  spores,  whence  the  name  Dispora  eaucasina.  When 
dried,  the  kephir  fungus  forms  hard  yellowish  grains  about  the  size  of  peas. 
By  soaking  these  in  water  and  adding  them  to  milk,  alcoholic  fermentation 
ensues  and  the  kephir  is  matured  in  a  few  days. 

The  following  figures  show  the  comparative  percentage  composition  of 
fresh  milk,  kephir,  and  koumiss : 


Fresh  Milk. 

Kephir. 

Koumiss. 

Fat 

3.8 

2.0 

2.05 

Proteids 

4.8 

3.8 

1.12 

Sugar   

4.1 

2.0 

2.20 

Lactic  acid  
Alcohol    

Trace. 
None. 

0.9 
0.8 

1.15 
1.65 

Water  and  salts 

87.3 

90.49 

91.83 

7.  CASEIN  PREPARATIONS. — Casein  is  now  utilized  on  a  large  scale, 
first,  as  a  basis  of  food  preparations ;  second,  as  a  fixing  agent  in  calico 
printing  instead  of  albumen ;  and  third,  as  a  substitute  for  glue  in  cements. 
For  the  first  class  of  compounds,  the  casein  salts  of  the  alkalies  and  alkaline 
earths  are  used,  and  are  obtained  by  dissolving  casein  in  the  calculated 
amount  of  caustic  alkali,  alkali  metal,  carbonate  or  phosphate  or  milk  of 
lime,  and  evaporating  the  solution  in  vacuo.  The  products  are  dry  white 
powders.  For  the  second  class  of  compounds,  casein  is  generally  dissolved 
in  ammonia,  the  solution  evaporated,  and  the  residue  mixed  with  milk  of 


ANALYTICAL  TESTS  AND   METHODS.  265 

lime.  Lactarine  is  a  commercial  preparation  of  this  class  used  as  a  fixing 
agent.  A  mixture  of  casein  with  slaked  lime  sets  to  a  hard  insoluble  mass, 
which  is  sometimes  employed  as  a  cement  for  earthenware  and  for  similar 
purposes  as  a  cheap  substitute  for  glue. 

In  making  these  casein  cements  the  most  important  point  that  is  to  be 
noted  to  insure  success  is  the  freeing  of  the  casein  from  all  oily  matter. 
Therefore,  when  curd  is  prepared  from  milk,  use  only  the  most_  carefully 
skimmed  milk  quite  free  from  cream.  When  cheese  is  used,  select  the 
poorest  and  wash  it  carefully.  The  washed  and  kneaded  casein  or  cheese 
is  thoroughly  mixed  with  quicklime  and  applied  quickly.  It  then  sets  very 
rapidly.  Silicate  of  soda  solution  and  borax  are  also  used  instead  of  quick- 
lime, and  form  excellent  cements  with  casein.  Kdseleim  pulver,  a  ready- 
made  Swiss  preparation,  will  set  when  moistened. 

8.  WHEY. — The  aqueous  liquid  remaining  after  the  separation  of  the 
butter-fat  and  the  casein,  or  curd,  is  termed  the  whey.  Its  more  important 
constituent  is  milk-sugar,  which  in  sour  whey  has  been  changed  in  part  into 
lactic  acid.  It  also  contains  soluble  nitrogenous  constituents,  such  as  milk- 
albumen  and  peptonized  casein.  On  account  of  these  constituents  it  is  an 
easily  digestible  preparation  and  one  assisting  digestion.  Hence  the  use  of 
the  u  whey  treatment"  in  medical  practice  for  dyspeptics  and  those  suffering 
from  enfeebled  digestion.  The  chief  importance,  however,  of  the  whey  is 
for  the  extraction  of  the  milk-sugar,  which  is  largely  carried  out  in  Switzer- 
land. Other  products  of  minor  and  local  importance  only  are  "  whey  but- 
ter," "  whey  alcohol,"  from  which  latter  "  whey  champagne"  is  made,  and 
"  whey  vinegar."  The  analysis  of  the  average  whey  has  already  been  given. 
(See  p.  253.) 

IV.  Analytical  Tests  and  Methods. 

1.  FOR  MILK. — The  specific  gravity  of  milk  is  an  indication  of  value, 
as  it  varies  according  to  the  content  of  fat,  being  higher  for  a  skimmed  milk 
than  for  a  whole  milk.  However,  when  the  cream  has  been  removed,  the  spe- 
cific gravity  may  be  reduced  to  that  of  normal  milk  by  the  addition  of  water, 
and  then  the  specific  gravity  determination  taken  alone  would  be  fallacious. 
Hence  the  detection  of  the  adulteration  of  milk  by  addition  of  water  cannot 
be  made  with  entire  accuracy  by  the  lactometer  or  specific  gravity  hydrometer 
in  use.  The  lactometer  officially  used  by  milk  inspectors  in  New  York  and 
other  States  indicates  specific  gravities  between  1.000  (the  specific  gravity 
of  water)  and  1.038.  A  specific  gravity  of  1.021  (taken  as  the  minimum 
density  of  genuine  milk)  is  also  marked  100°,  while  the  specific  gravity  of 
water  (1.000)  is  called  0°.  Hence  if  the  lactometer  read  70°,  the  sample 
is  supposed  to  contain  seventy  per  cent,  pure  milk  and  thirty  per  cent, 
water.  The  average  lactometric  strength  of  about  twenty  thousand  samples 
of  milk  examined  by  the  New  York  State  Dairy  Commissioner  in  the  year 
1884  was  110°,  equivalent  to  a  specific  gravity  of  1.0319.  Another  form 
of  lactometer  used  abroad  is  the  Quevenne-Miiller  instrument,  which  is 
graduated  in  absolute  specific  gravity  readings  between  the  limits  1.014  and 
1.042,  and  then  the  limits  of  pure  milk  (1.029  to  1.034)  indicated,  and 
degrees  of  dilution  with  water  also  indicated  as  the  specific  gravity  sinks 
below  this.  The  degree  of  adulteration  of  skimmed  milk  is  also  indicated 
on  the  instrument  in  the  same  way. 

The  total  solids  form  an  important  element  in  the  examination  of  milk. 


266  MILK  INDUSTRIES. 

In  some  States  the  minimum  percentage  of  total  solids  allowed  in  a  milk  is 
stated  by  law.  (In  Massachusetts  thirteen  per  cent. ;  in  New  York  and 
New  Jersey  twelve  per  cent.)  To  determine  the  water  and  total  solids,  five 
grams  of  milk  are  placed  in  an  accurately  weighed  flat-bottomed  platinum 
capsule  and  dried,  first  on  the  water-bath  and  afterwards  at  105°  C.,  until 
constant  weight  is  obtained.  Ritthausen  proposed  coagulating  the  milk 
with  a  few  cubic  centimetres  of  absolute  alcohol  before  beginning  the  drying, 
but  this  is  said  to  be  unnecessary. 

To  determine  the  ash,  ignite  the  residue  of  the  total  solids  just  obtained, 
first  over  a  small  flame  and  finally  at  a  dull  red  heat.  Cover  the  dish,  cool 
in  the  desiccator,  and  weigh. 

The  fat  determination  may  be  determined  roughly  by  the  "  cremometer" 
of  Chevallier,  which  is  a  graduated  jar  in  which  a  sample  of  fresh  milk 
is  stood  for  from  twenty-four  to  thirty-six  hours  and  then  the  height  of 
the  separated  cream  layer  read  off.  Remembering,  however,  that  all  the 
fat-globules  are  never  likely  to  rise  and  form  together  in  the  cream  layer, 
more  accurate  methods  are  seen  to  be  necessary.  A  volumetric  method 
of  much  greater  accuracy  is  that  of  the  lactobutyrometer  of  Marchand  as 
improved  by  Tollens  and  Schmidt.  In  this  the  measured  milk  sample,  to 
which  a  few  drops  of  sodium  or  ammonium  hydrate  has  been  added,  is  agi- 
tated with  ether,  and  then  alcohol  added,  and  the  agitation  repeated.  On 
standing  the  graduated  tube  in  warm  water  the  ethereal  layer  of  fat  sepa- 
rates out  on  top  the  alcoholic  ether,  and  can  be  read  off  and  the  percentage 
calculated  from  tables  prepared.  An  improved  form  of  the  lactobutyrome- 
ter has  been  described  by  Caldwell*  and  the  accuracy  of  the  method  es- 
tablished. Another  volumetric  method  based  upon  the  same  principle,  but 
more  complicated  in  its  details,  is  that  of  Soxhlet.  In  this,  the  milk  made 
alkaline  by  caustic  potash  is  shaken  with  ether,  and  the  ethereal  solution  of 
the  fat  rising  to  the  top  of  the  mixture  is  separated  and  its  specific  gravity 
determined.  Liebermann  has  also  described  a  third  volumetric  method, 
and  more  recently  f  Morse,  Piggot,  and  Burton  have  described  what  seems 
to  be  the  most  accurate  of  these  methods  for  the  determination  of  the  fat  of 
milk  volumetrically.  Their  method  consists  in  the  dehydration  of  the  milk 
by  means  of  anhydrous  copper  sulphate ;  the  extraction  of  the  fat  by  means 
of  low  boiling  petroleum-ether ;  the  saponification  of  the  butter  by  means 
of  an  excess  of  a  standard  solution  of  potassium  hydroxide  in  alcohol ;  and 
the  determination  of  the  excess  of  alkali  by  means  of  a  solution  of  hydro- 
chloric acid. 

More  generally  relied  upon  for  absolute  accuracy  are  the  gravimetric 
methods,  of  which  Adams's  is  generally  followed.  In  this  a  coil  of  white 
blotting-paper  (or  thick  filtering-paper)  previously  purified  with  ether  and 
dried  is  made  to  soak  up  the  milk  to  be  analyzed  from  a  weighed  beaker  or 
pipette.  The  paper  coil  is  then  dried  in  a  hot-air  oven  and  placed  in  a 
Soxhlet  (see  p.  79)  or  similar  fat-extraction  apparatus  connected  with  an 
inverted  condenser  and  the  fat  extracted  by  ether  or  petroleum-ether. 

The  albuminoids  are  estimated  by  evaporating  a  weighed  portion  of 
milk  to  dryness  and  making  a  combustion  of  the  residue  with  soda-lime  or 
by  the  Kjeldahl  method  of  conversion  into  ammonia  compounds  and  distil- 
lation from  an  alkaline  solution.  Professor  A.  R.  Leeds  J  prefers  to  deter- 

*  Amer.  Chem.  Journ.,  vii.  p.  243.  f  Ibid.,  ix.  pp.  108  and  222. 

J  Transactions  of  the  College  of  Physicians,  Philadelphia,  1884,  p.  263. 


ANALYTICAL  TESTS  AND  METHODS.  267 

mine  the  albuminoids  jointly  with  the  fat  by  the  precipitation  with  cupric 
sulphate  after  the  method  of  Ritthausen  as  modified  by  Gerber. 

The  estimation  of  the  milk-sugar  by  the  polariscope  is  rendered  difficult 
by  the  presence  in  milk  of  various  albuminoids,  all  of  which  turn  the  plane 
of  polarization  to  the  left,  and  the  ordinary  means  of  removing  these  albu- 
minoids by  a  solution  of  basic  acetate  of  lead  is  far  from  being  perfect.  Pro- 
fessor Wiley*  after  extensive  experiments  upon  this  has  adopted  j,  method  of 
optical  analysis,  using  acid  mercuric  nitrate  to  precipitate  the  albuminoids. 
He  takes  the  specific  rotatory  power  of  milk-sugar  as  (a)D  =  52.5.  For  de- 
tails of  his  procedure  the  reader  is  referred  to  his  publication.  Milk-sugar 
may  also  be  determined  either  volumetrically  or  gravi metrically  with  the  aid 
of  Fehling's  solution.  (See  p.  158.)  In  this  case,  it  is  also  necessary  to 
remove  the  albuminoids  first,  and  this  is  done  by  Ritthausen' s  method  of 
precipitation  with  copper  sulphate,  all  excess  of  this  reagent  being  removed 
with  caustic  potash  solution.  In  calculating  the  results  it  will  be  remem- 
bered that  the  copper  reducing  power  of  milk-sugar  is  70.5°  as  compared 
with  dextrose  at  100°. 

The  sugar  is  probably  most  accurately  determined  by  extraction  from 
the  fat-free  residue  with  weak  boiling  alcohol,  filtering  the  alcoholic  fluid, 
and  evaporating  to  dryness.  This  leaves  the  sugar  with  some  mineral  mat- 
ter. On  burning  and  determining  this  matter  as  ash  the  amount  of  sugar 
can  be  gotten. 

2.  FOK  BUTTER. — The  water  in  butter  is  determined  by  drying  five 
grammes  of  the  butter  in  a  platinum  dish  at  a  temperature  of  100°  C. 
(212°  F.)  or  slightly  higher.  The  melted  butter  is  stirred  from  time  to 
time  to  facilitate  the  escape  of  the  moisture.  The  water  will  have  been 
given  off  in  three  to  four  hours,  and  it  has  been  found  that  longer  heating 
sometimes  causes  the  melted  fat  to  gain  in  weight. 

To  determine  the  salt,  the  dried  butter  just  obtained  is  treated  with  warm 
ether  or  petroleum  spirit,  and  the  contents  of  the  platinum  dish  poured  on 
a  weighed  filter  and  washed  with  ether  until  all  fat  is  removed.  The  resi- 
due and  filter  are  dried  and  weighed.  The  salt  is  then  dissolved  out  by 
warm  water,  and  the  chlorides  in  the  solution  estimated  volumetrically  by 
tritration  with  decinormal  silver  nitrate,  using  a  few  drops  of  potassium 
chromate  as  indicator.  The  difference  between  the  weight  of  salt  ascer- 
tained and  the  total  weight  of  curd  and  salt  on  the  weighed  filter  is  regarded 
as  the  amount  of  the  casein,  or  curd,  present.  If  after  washing  out  the 
salt  the  residue  on  the  weighed  filter  be  dried  and  then  weighed,  the  amount 
of  casein  so  obtained  is  a  little  less  than  that  gotten  by  difference.  This  is 
partly  due  to  the  small  amount  of  milk-sugar  washed  out  along  with  the 
salt  and  undetermined,  and  partly  to  the  slight  solvent  action  of  warm  water 
on  some  of  the  curd. 

The  percentage  of  fat  may  be  obtained  by  evaporating  the  ether  filtrate 
from  the  previous  determination  of  salt  and  curd,  but  the  butter-fat  is  liable 
to  increase  in  weight  by  this  treatment,  and  therefore  the/a£  is  usually  got- 
ten by  difference  after  determining  the  water,  casein,  salt,  and  milk-sugar. 

The  adulteration  of  butter  and  the  manufacture  on  a  large  scale  of  butter 
substitutes  makes  an  examination  of  the  butter-fat  one  of  great  importance. 
This  examination  may  be  both  qualitative  and  quantitative.  The  butter- 
fat  is  gotten  for  examination  by  melting  a  sample  of  butter  and,  after  allow- 

*  Department  of  Agriculture,  Bulletin  No.  13,  Part  i.  p.  113. 


268  MILK   INDUSTRIES. 

ing  the  water  and  curd  to  settle,  pouring  the  clear  fat  on  to  a  dry  warm 
ribbed  filter  and  collecting  the  filtrate. 

The  specific  gravity  of  the  butter-fat  may  be  taken,  as  first  suggested 
by  Bell,  in  a  specific  gravity  bottle  at  a  temperature  of  100°  F.  (37.7  C.), 
or,  as  suggested  by  Estcourt  and  endorsed  by  Allen,  with  the  aid  of  the 
Westphal  balance  (see  p.  80)  at  a  temperature  of  99°  to  100°  C.  (210°  to 
212°  F.).  Bell  found  by  his  method  that  the  specific  gravity  of  true  but- 
ter-fat varied  from  909.4  to  914  (water  1000),  while  butterine  showed  a 
specific  gravity  of  901.4  to  903.8.  Allen  gives  the  limit  for  pure  butter- 
fat  tested  at  99°  C.  as  867  to  870,  while  butterine  at  the  same  temperature 
was  858.5  to  862.5. 

The  melting  point  of  the  butter-fat  is  also  generally  noted.  Bell  pro- 
posed determining  the  melting  point  by  first  suddenly  cooling  some  melted 
butter-fat  by  floating  the  capsule  containing  it  upon  ice-water,  and  then 
taking  a  fragment  of  the  congealed  butter  upon  the  loop  of  a  platinum  wire. 
This  is  then  introduced  close  to  the  bulb  of  a  thermometer  in  a  beaker  of 
water  which  is  being  heated  from  without.  As  the  water  becomes  warmed 
the  globule  melts  and  the  thermometer  is  read  off.  An  improvement  on 
the  method  insuring  greater  accuracy  is  recorded  in  Bulletin  of  the  Depart- 
ment of  Agriculture,  No.  19,  p.  72.  The  melting  point  of  butter  usually 
ranges  between  29.5°  C.  and  33°  C.  (85°  to  90°  F.),  while  the  melting  point 
of  butterine  is  stated  to  be  between  25.5°  C.  and  28°  C.  (77.9°  to  82.4°  F.). 

The  quantitative  examination  of  the  supposed  butter-fat  may  be  made 
by  several  methods, — viz.,  the  determination  of  the  saponification  equivalent 
by  Koettstorfer's  method,*  the  determination  of  the  percentage  of  insoluble 
fatty  acids  present  as  glycerides  by  Hehner's  method,f  and  the  determination 
of  the  volatile  fat  acids  after  distillation  by  Rekhert's  method.!  To  these 
most  generally  received  methods  may  also  be  added  the  method  of  Hiibl  of 
iodine  saturation  as  determining  the  character  of  fatty  acids,  and  the  method 
of  Morse  and  Burton,  which  combines  the  Koettstorfer  and  the  Hehner 
processes,  and  determines  the  saponification  equivalent  of  the  soluble  and 
the  insoluble  fat  acids  separately. 

The  term  "  saponification  equivalent"  is  used  to  indicate  the  number  of 
grammes  of  an  oil  saponified  by  one  equivalent  in  grammes  of  an  alkali. 
Thus,  tributyrin  (the  glyceride  of  butyric  acid)  has  a  saponification  equiva- 
lent of  100.67,  while  tristearine  (the  glyceride  of  stearic  acid)  has  a  saponi- 
fication equivalent  of  296.67.  Butter-fat,  it  will  be  remembered,  is  a  mix- 
ture of  the  several  glycerides  of  the  lower  or  volatile  fatty  acids  and  the 
higher  or  non-volatile  fatty  acids.  Its  saponification  equivalent  ranges  from 
241  to  253,  the  average  being  247  ;  butterine  has  a  saponification  equivalent 
ranging  from  277  to  294,  the  average  being  285.5.  In  Hehner's  method,  the 
weighed  quantity  of  the  fat  is  saponified  by  alcoholic  potash,  the  soap  solu- 
tion evaporated  down,  taken  up  with  water,  and  the  fatty  acids  set  free  by 
an  excess  of  hydrochloric  acid.  They  are  now  brought  upon  a  weighed 
filter,  washed  with  boiling  water  until  no  longer  acid,  and  then  chilled  into 
a  cake  by  immersing  the  filter  in  cold  water.  The  filter  is  then  transferred 
to  a  weighed  beaker-glass  and  the  contents  dried  at  100°  C.  until  constant 
in  weight.  The  soluble  fat  acids  can  also  be  determined  in  this  process  by 

*  Allen,  Commercial  Organic  Analysis,  2d  ed.,  vol.  ii.  p.  40. 
f  Bell,  Analysis  and  Adulteration  of  Foods,  Part  ii.  p.  56. 
\  Allen,  Commercial  Organic  Analysis,  2d  ed.,  vol.  ii.  p.  45. 


ANALYTICAL  TESTS  AND  METHODS.  269 

collecting  the  washings  which  were  obtained  with  boiling  water  and  making 
them  up  to  one  hundred  cubic  centimetres  and  then  carefully  titrating  an 
aliquot  portion  with  decinormal  soda  solution.  This  will  give  the  amount 
of  soluble  fat  acids  plus  the  excess  of  standard  hydrochloric  acid  used  orig- 
inally in  liberating  the  fat  acids.  The  amount  of  this  excess  can  be  ascer- 
tained by  carrying  through  a  blank  experiment  with  alcoholic  potash  and 
hydrochloric  acid,  but  without  the  fat.  In  the  analysis  of  butter-fat  the 
sum  of  the  insoluble  fatty  acids  and  of  the  soluble  fatty  acids  calculated  as 
butyric  acid  should  always  amount  to  fully  ninety-four  per  cent,  of  the  fat 
taken.  The  soluble  fatty  acids  calculated  as  butyric  acid  should  amount  to 
at  least  five  per  cent.,  any  notably  smaller  proportion  being  due  to  adultera- 
tion. As  an  average,  eighty-eight  per  cent,  of  insoluble  and  five  and  a  half 
per  cent,  of  soluble  acids  should  be  obtained. 

While  the  true  percentage  of  the  volatile  fatty  acids  cannot  be  easily 
obtained,  the  amount  of  alkali  needed  to  neutralize  them  after  distillation 
can  be  determined  by  Reichert's  process.  According  to  this,  as  improved 
by  Meissl,  five  grammes  of  the  fused  and  filtered  fat  are  placed  in  a  flask 
of  about  two  hundred  cubic  centimetres  contents  with  about  two  grammes 
solid  caustic  potash  and  fifty  cubic  centimetres  of  seventy  per  cent,  alcohol, 
saponified  on  the  water-bath  and  evaporated  down  until  all  alcohol  is  driven 
off.  The  thick  soap-mass  remaining  is  now  dissolved  in  one  hundred  cubic 
centimetres  of  water,  forty  cubic  centimetres  of  dilute  sulphuric  acid  added, 
and,  after  adding  a  few  fragments  of  pumice-stone,  distilled  with  the  aid  of 
a  Liebig  condenser.  About  one  hundred  and  ten  cubic  centimetres  of  dis- 
tillate are  collected,  which  requires  about  an  hour.  Filter  and  collect  one 
hundred  cubic  centimetres  in  a  graduated  flask.  Add  phenol-phthalein  as 
an  indicator,  and  titrate  with  decinormal  alkali.  Increase  the  result  by  one- 
tenth,  and  reckon  the  result  upon  five  grammes  of  the  substance.  It  is 
found  that  two  and  a  half  grammes  of  butter-fat,  examined  by  Reichert's 
method,  require  about  thirteen  cubic  centimetres  of  the  decinormal  alkali, 
while  butterine  requires  only  one  cubic  centimetre.  As  the  difference  be- 
tween these  is  twelve  cubic  centimetres,  it  may  be  calculated  that  there  is 
8.5  per  cent,  real  butter-fat  present  in  a  mixture  for  every  cubic  centi- 
metre of  alkali  required  over  the  one  cubic  centimetre  required  for  ordinary 
butterine. 

HubFs  method  is  founded  on  the  fact  that  the  three  series  of  fatty  acids 
(acetic,  acrylic,  and  tetrolic)  unite  in  different  proportions  with  the  halogens, 
like  chlorine,  bromine,  and  iodine,  to  form  addition  products.  The  number 
of  grammes  of  iodine  absorbed  is  calculated  to  one  hundred  grammes  of 
fat,  and  this  is  HiibPs  "  iodine  number."  Thus  genuine  butter  has  an  iodine 
number  from  30.5  to  43.0,  while  oleomargarine  has  from  50.9  to  54.9. 

Morse  and  Burton  *  saponify  the  combined  fatty  acids,  liberate  the  free 
acids,  wash  out  the  soluble  portion  of  the  mixture,  and  then  saponify  again 
the  soluble  and  the  insoluble  acids  separately.  They  thus  combine  the 
Koettstorfer  and  the  Hehner  processes  and  get  a  greater  certainty  as  to  the 
character  of  the  fat  mixture.  Thus  they  find  that  with  butter  86.57  per 
cent,  of  potassium  hydrate  is  required  to  neutralize  the  insoluble  acids  and 
13.17  per  cent,  to  neutralize  the  soluble  acids,  while  with  oleomargarine 
95.40  per  cent,  of  potassium  hydrate  is  required  for  the  insoluble  acids  and 
4.57  per  cent,  for  the  soluble  acids. 

*  Amer.  Chem.  Journ.,  x.  p.  322. 


270  MILK   INDUSTRIES. 

Perkins*  has  devised  a  similar  process,  which  goes  further  and  distils 
off  the  volatile  fatty  acids  from  the  soluble  portion  washed  out  of  the  fatty 
acid  mixture,  thus  combining  the  features  of  the  Reichert  process  with  those 
of  the  other  two. 

The  chief  coloring  matter  added  to  butter  are  the  vegetable  dyes  annato, 
carotin,  fustic,  turmeric,  marigold,  and  saffron,  the  coal-tar  dyes  Victoria 
and  Martius  yellow,  and  sometimes  chrome-yellow  (chromate  of  lead). 
The  following  short  scheme  of  testing  will  show  the  nature  of  the  butter- 
color  in  most  cases : 

Dissolve  the  supposed  artificially-colored  butter  in  alcohol  and  add, — 

a.  Nitric  acid  :  greenish  coloration,  saffron. 

b.  Sugar  solution  and  hydrochloric  acid  :  red  coloration,  saffron. 

c.  Ammonia  :   brownish  coloration,  turmeric. 

d.  Silver  nitrate  :  blackish  coloration,  marigold. 

e.  Evaporate  the  alcoholic  solution  to  dryness  and  add  concentrated  sul- 
phuric acid  :  greenish-blue  coloration,  annato  ;  blue  coloration,  saffron. 

f.  Hydrochloric  acid  :  decolorization,  with  formation  of  yellowish  crys- 
talline precipitate,  Victoria  or  Martius  yellow. 

g.  Separation  of  a  heavy  and  insoluble  yellow  powder  :  chrome-yellow. 

3.  FOR  CHEESE. — The  methods  employed  in  cheese  analysis  are  in  most 
respects  the  same  as  those  employed  in  the  examination  of  butter.  The  fat 
is  best  extracted  with  light  petroleum-ether,  as  common  ether  dissolves  the 
free  lactic  acid  as  well  as  the  fat.  The  remaining  solids  not  fat  can  then  be 
dried  and  weighed.  The  fat  should  be  examined  by  Koettstorfer's  saponi- 
fication  equivalent  method,  as  the  oleomargarine  and  lard  cheeses  may  be 
detected  in  this  way.  Genuine  cheese-fat,  according  to  Muter,  f  should  not 
consume  less  than  two  hundred  and  twenty  milligrammes  of  potassium 
hydrate  for  each  gramme  used.  If  the  cheese  should  give  unfavorable 
indications  with  Koettstorfer's  test,  then  the  soluble  and  insoluble  fatty 
acids  are  determined  in  the  fat  according  to  Hehner.  The  percentage  of 
insoluble  fat  acids  in  genuine  cheese,  according  to  Muter,  averages  88.5, 
while  in  oleomargarine  cheeses  it  is  from  90.5  to  92  per  cent. 

The  acidity,  calculated  as  lactic  acid,  may  be  determined  by  treating 
the  residue  from  the  fat  determination  with  water  and  titrating  the  washings 
with  decinormal  soda  solution.  The  washed  residue  then  is  the  non-fatty 
solids. 

The  ash  is  determined  by  ignition  of  the  dried  cheese  before  extraction 
of  the  fat. 

V.  Bibliography  and  Statistics. 

BIBLIOGKAPHY. 

1875. — Das  Molkereiwesen,  W.  Fleischmann,  Braunschweig. 

1876. — Dictionary  of  Hygiene,  with  Detection  of  Adulterations,  A.  W.  Blyth,  London. 

1878. — Butter,  its  Analysis  and  Detection,  Angell  &  Hehner,  2d  ed.,  London. 

Illustrirtes  Lexikon  der  Verfalschungen  der  Nahrungsmittel,  H.  Kluncke,  Leip- 
zig. 

Die  Fabrikation  der  Kunstbutter,  Sparbutter,  etc.,  Lang,  Leipzig. 
1879. — Instruction  sur  1'Essai  et  1'Analyse  du  Lait,  Bouchardat  et  Quevenne,  3me  ed., 

Paris. 
1881. — The  Analysis  and  Adulteration  of  Foods,  James  Bell,  London. 


*  Zeitsch.  fur  Anal.  Chem.,  xix.  p.  237.  f  Analyst,  vol.  x.  p.  3. 


BIBLIOGRAPHY  AND   STATISTICS.  271 

1882. — Food,  Sources,  Constituents,  and  Uses,  A.  H.  Church,  London. 

Chevallier's  Dictionnaire  des  Alterations  et  Falsifications,  6me  ed.,  Baudrimont, 
Paris. 

The  Analysis  of  Milk,  Condensed  Milk,  etc.,  N.  Gerber,  New  York. 
1884. — Falsifications  des  Matieres  alimentaires,  Laboratoire  Municipal,  Paris. 

Die  Conservirung  von  Milch,  Eier,  etc.,  C.  Heinzerling,  Halle. 
1885. — Fabrikation  von  Kunstbutter,  V.  Lang,  2te  Auf.,  Leipzig. 
1886. — Ueber  Kunstbutter,  ihre  Herstellung,  etc.,  Eugen  Sell,  Berlin. 

Milk  Analysis,  J.  Alfred  Wanklyn,  2d  ed.,  London. 

Die  Analyse  der  Milch,  E.  Pfeifler,  2d  ed.,  Wiesbaden. 

Des  Laits  fermentes  et  leurs  Usages,  Saillet,  Paris. 
1887.— Food  Adulteration  and  its  Detection,  J.  P.  Battershall,  New  York. 

United  States  Department  of  Agriculture,  Bulletin  No.  13,  Part  i.  (Dairy  Products), 
H.  W.  Wiley,  Washington. 

United  States  Department  of  Agriculture,  Bulletin  No.  16  (Methods  of  Analysis  of 
Dairy  Products,  etc.),  C.  Richardson,  Washington. 

Le  Lait,  Etudes  chimiques  et  Microbiologiques,  Duclaux,  Paris. 

Illustrirtes  Lexikon  der  Yerfalschungen,  etc.,  Dammer,  Leipzig. 

1888. — United  States  Department  of  Agriculture,  Bulletin  No.   19   (Analysis  of  Dairy 
Products),  C.  Richardson,  Washington. 

Foods,  their  Composition  and  Analysis,  2d  ed.,  A.  W.  Blyth,  London. 
1889. — Chemie der  Menschlichen  Nahrungs- und  Genussmittel,  J.  Konig,  3te  Auf.,  Berlin. 

La  Margarine  et  le  Beurre  artificiel,  Girard  et  Brevans,  Paris. 
1891. — Die  Untersuchung  landwirthschaftlich  wichtiger  Stoffe,  J.  Konig,  Berlin. 

Handbuch  der  Milch wirthshaft,  Kirchner,  3te  Auf.,  Berlin. 
1893. — Traite  general  d'Analyse  des  Beurres,  2  tomes,  A.  J.  Zune,  Paris. 

Dairy  Chemistry  for  Dairy  Managers,  H.  D.  Richmond,  London. 
1894. — Milk,  Cheese,  and  Butter :  a  Practical  Handbook,  J.  Oliver,  London. 
1895. — Dairy  Bacteriology,  E.  von  Freudenreich,  translated  by  J.  R.  Davis,  London. 
1896. — The  Analysis  of  Milk  and  Milk  Products,  Leffman  and  Beam,  2d  ed.,  Philadelphia. 

The  Book  of  the  Dairy,  W.  Fleischmann,  translated  by  Aikman  and  Wright. 

London. 

1897. — The  Chemistry  of  Dairying,  Harry  Snyder,  Easton,  Pa. 
1898. — Testing  Milk  and  its  Products,  Farrington  and  Woll,  3d  ed.,  Madison,  Wis. 
1899. — Milk,  its  Nature  and  Composition.     A  Handbook.     C.  M.  Aikman,  2d  ed.,  New 
York. 

Dairy  Chemistry :  a  Practical  Handbook,  H.  D.  Richmond,  London, 

STATISTICS. 

In  the  absence  of  any  governmental  control  of  the  milk  industries  no 
statistics  of  production  representing  the  entire  country  can  be  given  except 
for  oleomargarine. 

For  butter  and  cheese  consumption  accurate  figures  can  be  given  for  the 
amount  handled  at  the  port  of  New  York,  and  from  that  estimates  can 
be  made  with  some  approximation  to  the  truth  for  the  country  generally. 
The  following  figures  and  estimates  for  the  years  named  are  given  on  the 
authority  of  H.  R.  Chambers,  statistician  for  the  New  York  Mercantile 
Exchange. 

The  New  York  market  is  figured  to  have  fed  during  the  last  five  years 
an  average  of  one  million  seven  hundred  and  fifty  thousand  people  yearly. 
The  receipts  and  exports  at  that  port  were  in  packages  of  fifty  pounds  each. 

RECEIPTS.  EXPORTS. 


Butter.  Cheese.                Butter.  Cheese. 

1890 1,890,949  1,987,217            373,982  1,496,798 

1889 2,044,448  1,931,015            398,819  1,500,930 

1888 1,697,909  1,993,462            140,993  1,516,614 

1887 1,678,660  1,994,857            188,541  1,450,590 

1886 1,648,220  1,943,260            233,552  1,575,268 

The  average  receipt  yearly,  less  the  average  yearly  export,  will  give  the 

average  consumption  (approximately)  of  one  million  seven  hundred  and 


272  MILK  INDUSTRIES. 

fifty  thousand  people.  1,785,000  —  266,000  =  1,51 9,000  packages  of  fifty 
pounds  each  for  one  million  seven  hundred  and  fifty  thousand  people,  or 
forty-three  and  one-third  pounds  for  each  person,  a  year  as  'he  consumption 
of  butter. 

In  rural  districts  the  consumption  is  much  greater  and  the  waste  is 
greater,  so  that  an  average  would  bring  the  personal  consumption  easily  to 
fifty  pounds  each,  which  may  be  reckoned  on  the  population  of  the  country. 
Very  little  under-  or  over-production  seems  to  exist,  if  we  estimate  the 
great  steadiness  of  price  during  this  period. 

The  production  of  butter  and  cheese  of  the  State  of  New  York  for  the 
year  1892  is  thus  given  by  the  New  York  State  Board  of  Agriculture  in  a 
report  published  in  1894  : 

Pounds. 

Number  of  butter  factories  .    .    255,  in  which  butter  was  made  .    14,024,019 

Number  of  cheese        "        .    .1156,         "        cheese    «       «     .110,605,691 

Number  of   factories  making          )  amount  of  butter  in  all .   .    19,497,357 

both  butter  and  cheese  .    .    .    213  /          "         cheese     "     .    .131,148,310 

The  exportation  of  dairy  products  from  the  United  States  for  the  last 
few  years  has  been  as  follows : 

1896.  1897.  1898.  1899. 

Butter  (pounds) 19,373,913  31,345,224  25,690,025  20,247,997 

Valued  at $2,937,203  $4,493,364  $3,864,765  $3,263,951 

Cheese  (pounds) 36,777,291  50,944,617  53,167,280  38,198,753 

Valued  at $3,091,914  $4,636,063  $4,509,324  $3,316,049 

Oleomargarine  butter  (pounds)     6,063,699  4,864,351  4,328,536  5,549,322 

Valued  at $587,269  $472,856  $386,297  $509,703 

Oleo  oil  (pounds) 103,276,756  113,506,152  132,579,277  142,390,492 

Valued  at $8,087,905  $6,742,061  $7,904,413  $9,183,659 

The  production  of  oleomargarine  in  the  United  States  for  the  last  few 
years,  according:  to  the  returns  of  the  Internal  Revenue  Department,  has 
been:  1896,  47,023,773  pounds ;  1897,  42,534,559  pounds;  1898,  55,388,- 
727  pounds;  1899,  80,495,628  pounds. 

The  greater  quantity  of  the  "  oleo  oil"  exported  from  the  United  States 
goes  to  Holland,  where  it  is  converted  into  oleomargarine.  The  English 
importation  of  oleomargarine  (or  "  margarine/'  as  it  is  officially  known  there) 
for  the  years  1892  and  1893  was  as  follows  : 

1892.  1893 

Quantity,  cwt 1,305,350  1,299,970 

Valued  at £3,712,884  £3,655.344 


GENERAL  CHARACTERS   OF  VEGETABLE   FIBRES.  273 


CHAPTER   VIII. 

VEGETABLE   TEXTILE   FIBRES. 

General  Characters. 

ALL  the  fibres  which  have  been  found  of  technical  value  for  manufacturing 
purposes  may  be  divided  into  the  two  great  classes,  vegetable  fibres  and  ani- 
mal fibres,  the  few  found  in  the  mineral  kingdom  among  fibrous  minerals 
being  of  relatively  slight  importance  in  textile  manufacturing.  Moreover, 
the  distinction  is  not  merely,  as  the  name  chosen  would  indicate,  one  of 
origin,  but  fundamental  structural  and  chemical  differences  also  exist  and 
make  themselves  evident  upon  the  slightest  examination.  The  vegetable 
fibres  are  exclusively  cell-growths  of  relatively  simple  structure,  which  dur- 
ing their  life  form  integral  parts  of  the  plant  organisms,  while  the  animal 
fibres  may  be  either  a  hardened  secretion  like  silk  or  a  more  complicated 
cell-growth  like  wool,  distinguished  by  its  scale-like  surface. 

Thus  the  vegetable  fibres  are  without  exception  some  form  of  cellulose 
(C6H10O5)n  in  more  or  less  pure  condition  or  an  alteration  product  of  the 
same,  while  the  animal  fibres  are  composed  of  protein  matter,  and  hence  are 
nitrogenous. 

The  radical  character  of  their  chemical  difference  just  referred  to  will 
be  more  thoroughly  appreciated  when  we  note  the  action  of  reagents  upon 
the  two  classes  respectively.  The  vegetable  fibres  are  not  dissolved  or 
weakened  by  alkalies  even  at  a  boiling  temperature,  while  the  animal  fibres 
are  speedily  disintegrated,  with  eventual  liberation  of  ammonia  from  the 
nitrogenous  material ;  while,  on  the  other  hand,  sulphuric  or  hydrochloric 
acid  rapidly  causes  a  disintegration  of  the  vegetable  fibres  by  their  action 
upon  the  cellulose,  and  nitric  acid  either  oxidizes  the  cellulose  or  gives  rise 
to  nitrated  derivatives,  while  the  animal  fibres  are  only  slightly  affected 
even  when  the  acids  are  concentrated.  These  reactions  will  be  referred  to 
more  fully  in  speaking  of  the  analytical  tests  used  for  distinguishing  the 
fibres  in  mixed  goods.  (See  p.  316.) 

The  several  vegetable  fibres  may  be  classified  according  to  botanical  or 
morphological  character  into  three  groups :  (1)  Seed-hairs  (filaments  com- 
posed of  individual  cells) ;  (2)  bast  fibres  (filaments  or  fibre-bundles  made 
up  of  individual  fibre-cells  aggregated  together) ;  and  (3)  fibro-vascular 
bundles.  Sometimes  the  term  bast  fibres  is  made  to  include  both  the  second 
and  third  classes  as  just  given. 

Chemically,  all  vegetable  fibres  are  composed  of  cellulose.  However, 
it  has  long  been  known  that  it  is  frequently  more  or  less  contaminated  with 
altered  products,  which  have  been  known  as  lignin,  ligno-cellulose,  adipo- 
cellulose,  etc.  The  recent  researches  of  Messrs.  Cross  and  Bevan  have 
given  us  a  clear  understanding  of  the  nature  of  the  lignin  and  the  altera- 
tion products  of  cellulose.  The  combination  of  cellulose  and  lignin,  to 
which  they  apply  the  name  of  bastose,  may  make  up  the  whole  bundle  of 
fibres,  as  in  jute,  or  may  be  merely  a  covering  upon  the  unaltered  cellulose. 

18 


274 


VEGETABLE  TEXTILE   FIBRES. 


By  distinguishing  between  the  cellulose  and  the  bastose  and  mixtures  of  the 
two  we  may  establish  a  chemical  classification  of  the  vegetable  fibres.  We 
are  enabled  to  do  this  by  the  aid  of  the  solutions  of  iodine  (potassium  iodine 
solution  saturated  with  free  iodine)  and  sulphuric  acid  (concentrated  glycer- 
ine and  strong  sulphuric  acid),  which  were  first  proposed  by  Ve"tillart.* 
Pure  cellulose  when  tested  with  the  iodine  and  sulphuric  acid  solutions,  one 
after  the  other,  will  give  a  pure  blue  color,  while  bastose  shows  under  these 
conditions  a  yellow  coloration.  A  complete  classification,  taking  both  botani- 
cal and  chemical  characters  into  account,  is  the  following,  which  is  that  of 
Cross  and  Bevan's  f  with  some  additions  : 


Blue  reaction    with    iodine  •> 
and  sulphuric  acid. 


Yellow  reaction  with  iodine  n 
and  sulphuric  acid. 


A. 

Seed-hairs. 


Cotton. 


B. 

Dicotyledonous 

bast  fibres. 
Linen. 
Hemp. 
China-grass. 
Kamie. 
Nettle. 
Sunn  fibre. 


Hibiscus. 
Jute. 


C. 

Monocotolydonous  fibres  cor- 
responding to  bast  fibres. 
Straw. 
Pineapple. 
Esparto. 
Alfa. 


New  Zealand  flax. 

Aloe. 

Yucca. 

Manila  hemp. 

Coir. 


1.  COTTON  FIBRE. — The  cotton,  as  already  noted,  is  a  seed-hair  and 
envelops  the  seeds,  which  are  at  first  enclosed  in  a  capsule.  With  the  ripen- 
ing of  the  plant  this  capsule  bursts  and  the  contents  spread  out  widely,  con- 
stituting the  cotton-boll,  which  is  easily  picked.  The  separation  of  the 
fibre  from  the  enclosed  seed  is  afterwards  accomplished  by  the  mechanical 
operation  called  "  ginning,"  in  which  it  is  torn  from  the  seed,  so  that  while 
one  end  of  an  individual  fibre  is  always  closed  the  other  is  irregularly 
broken. 

The  genus  Gossypium,  to  which  all  cotton-plants  are  referred, .  includes 
several  well-marked  varieties,  the  most  important  of  which  are  G.  Barbe- 
dense,  or  "  sea-island  cotton,"  grown  off  the  coast  of  Georgia,  South  Caro- 
lina, and  Florida,  which  yields  the  longest  and  strongest  fibre  or  the  finest 
"  staple ;"  the  G.  hirsutum,  or  upland  cotton,  grown  inland  in  Georgia,  Ala- 
bama, Louisiana,  and  Mississippi,  which  yields  a  shorter  staple ;  the  G.  her- 
baceum,  grown  in  Egypt,  Asia  Minor,  and  India ;  the  G.  arboreum,  grown 
in  India  and  Egypt ;  the  G.  religiosum,  grown  in  China  and  India  and 
yielding  the  so-called  "  nankin"  cotton  of  brown-yellow  color ;  and  the  G. 
Peruvianurrij  yielding  the  long-stapled  Brazilian  and  Peruvian  cotton. 

The  structure  of  the  cotton  fibre  is  very  characteristic.  It  presents  a 
flattened  and  collapsed  tube  slightly  twisted  in  spiral  form,  with  compara- 
tively thick  walls  and  a  small  central  opening.  This  structure  is  illustrated 
in  Figs.  78  and  79,  in  the  first  of  which  the  fibre  is  magnified  thirty  times 
and  in  the  second  of  which  it  is  magnified  two  hundred  times.  The  first 
illustration  shows  the  spiral  twist  of  the  fibres  distinctly,  but  the  collapsed 
character  of  the  tube  only  slightly ;  this  latter  feature,  however,  is  shown 
very  distinctly  in  the  second  illustration.  This  flattening  is  not  seen  in  the 
unripe  fibre,  which  is  a  tube  filled  with  liquid  protoplasmic  matter,  but  in 
the  ripening  of  the  plant  this  liquid  dries  up  and  the  walls  of  the  tube 


*  Vetillart,  Etudes  sur  les  Fibres,  Paris,  1876. 
t  Text-book  of  Paper-Making,  p.  46. 


GENERAL  CHARACTERS   OF  VEGETABLE   FIBRES.  275 

collapse  and  flatten  out.  The  adhesion  of  the  fibre  to  the  seed  also  becomes 
less,  so  that  the  ripe  cotton  is  easily  separated  in  the  ginning  process.  In 
some  species  (as  in  G.  Barbadense)  this  separation  of  hair  from  the  seed  is 
so  perfect  that  the  seed  shows  after  the  ginning  a  lustrous  black  appearance, 
whence  the  name  locally  applied  of  "  black-seed  cotton"  as  distinguished 
from  the  upland  variety,  known  as  "  green-seed  cotton." 

X.. 

FIG.  78.  FIG.  79. 


The  fibre  must  be  picked  when  mature  or  it  becomes  "  over-ripe"  and 
deteriorates.  The  length  of  the  u  staple,"  or  fibre,  varies  considerably  with 
the  different  varieties  of  the  cotton,  the  long-stapled  sea-island  cotton  grown 
on  the  shores  of  Georgia  and  Florida  attaining  a  length  of  nearly  two- 
inches  (five  centimetres),  while  the  short  native '  cotton  of  India  scarcely 
exceeds  three-quarters  of  an  inch  (eighteen  millimetres)  in  length.* 

Chemically,  the  cotton  fibre  contains  about  ninety-one  per  cent,  of  pure 
cellulose,  seven  per  cent,  of  moisture,  and  small  amounts  of  fat,  nitrogen- 
ous material,  and  cuticular  substance.  An  ammoniacal  solution  of  copper 
oxide  causes  the  cellulose  material  of  the  fibre  to  soften  and  swell  upr 
whereby  the  cuticle,  which  is  not  softened,  takes  the  appearance  of  yellow- 
ish constricting  rings  binding  the  swollen  cellulose  at  regular  intervals. 
Prolonged  action  of  the  reagent  dissolves  the  cellulose.  When  bleached 
by  boiling  with  sodium  carbonate  or  hydrate,  the  cuticle  is  decomposed  and 
the  fibre  yields  easily  a  very  pure  form  of  cellulose. 

2.  FLAX. — The  flax-plant,  Linum  usitatissimum,  yields  the  best  known 
and  probably  the  most  valuable  of  the  bast  fibres  as  well  as  other  products, 
like  the  linseed  oil  and  linseed  cake.  (See  p.  49.)  It  is  not  grown  for 
both  fibre  and  seed  together,  however,  as  when  the  fibre  is  desired  in  best 
condition  the  plant  is  gathered  before  it  is  fully  matured,  while  if  the  plant 
is  allowed  to  ripen  fully  for  production  of  seed,  the  fibre  obtained  is  more 
stiff  and  coarse. 

The  plant  is  grown  through  a  wide  range  of  climate,  although  that 
grown  in  the  tropics,  as  in  India,  is  chiefly  used  for  seed,  the  fibre  being  of 
little  value,  while  that  grown  in  colder  countries,  as  in  the  Russian  East 
Sea  provinces,  yields  the  best  fibre.  When  the  plant  is  cultivated  for  the 
production  of  fibre,  it  is  either  sowed  more  thickly  or,  as  in  Holland  and 

*  Bowman,  Structure  of  the  Cotton  Fibre,  p.  19. 


276 


VEGETABLE   TEXTILE   FIBRES. 


Belgium,  forced  to  grow  up  through  a  net-work  of  brushwood,  thus  yield- 
ing a  more  slender  plant  with  a  longer  and  finer  fibre,  known  as  tin  rame. 
The  plant  is  not  cut,  but  is  always  carefully  pulled  up  by  the  roots,  and  the 
freshly  pulled-up  flax  is  at  once  submitted  to  the  process  of  seeding,  or 
"  rippling,"  which  is  to  remove  the  leaves  and  seed  capsules.  This  is 
usually  done  by  hand,  drawing  the  bundles  of  the  flax  through  upright 
metallic  combs,  or  "  ripples,"  the  prongs  of  which  easily  catch  the  seed 
capsules,  so  that  three  or  four  drawings  suffice  to  clean  the  stems  or  flax 
straws. 

This  straw,  as  it  is  termed,  contains  in  a  dried  condition  seventy-three 
or  eighty  per  cent,  of  its  weight  of  woody  matter  and  encrusting  material 
and  twenty  to  twenty-seven  per  cent,  of  bast  fibre. 

The  distinction  between  the  several  parts  of  the  stem  in  the  flax  and 
similar  plants  yielding  bast  fibres  is  shown  in  Fig.  80  by  both  transverse  and 
longitudinal  cross-sections,  where  1  represents  the  pith,  2  the  woody  tissue, 
3  the  cambium  or  partially  lignified  tissue,  4  the  bast  fibre,  and  5  the  crust 
or  rind.  To  free  these  several  parts  of  the 
stem  from  each  other  so  as  to  obtain  in  a  FIG.  80. 

clean  state  the  bast  fibre  is  the  object  of  the 
process  of  "  retting."  This  is  done  either 
by  natural  means,  as  in  the  case  of  dew 
retting  and  cold-water  retting,  or  by  the  help 
of  an  artificial  process,  as  in  warm-water 
retting  and  chemical  retting.  The  dew  ret- 
ting, applied  most  largely  in  Russia,  consists  in  leaving 
the  flax  thinly  spread  exposed  to  dew  and  rain,  air  and 
light,  for  eight  or  ten  weeks,  when,  by  the  fermentation 
of  the  pectose  matter  of  the  rind,  the  bast  fibre  is  thor- 
oughly loosened.  In  cold-water  retting  either  running  or 
stagnant  water  may  be  used,  the  former  being  used  in 
Belgium  and  the  latter  in  Ireland.  The  bundles  of  flax 
are  placed  in  crates  and  submerged,  when  actual  fermenta- 
tion ensues.  The  water  must  be  soft  water,  and  care  must 
be  taken,  especially  in  the  stagnant-water  method,  to  prevent  undue  heat- 
ing up  during  the  fermentation.  The  warm-water  retting  requires  a  tem- 
perature of  30°  to  35°  C.,  and  can  be  carried  to  completion  in  fifty  to  sixty 
hours,  yielding  an  excellent  product.  The  chemical  process  consists  in  the 
use  of  dilute  sulphuric  acid  or  hydrochloric  acid,  which  allow  of  the  com- 
pletion of  the  process  in  a  few  days.  After  the  retting  process  the  flax 
is  well  washed  and  dried,  and  is  then  submitted  to  the  mechanical  processes 
of  "  breaking,"  "  scutching,"  and  "  hackling"  to  thoroughly  free  the  fibre 
from  the  woody  layer  and  draw  out  the  fibre-bundles  into  filaments. 

The  flax  fibre  as  seen  under  the  microscope  seems  to  be  a  long  straight 
and  transparent  tube  with  thick  walls  and  a  minute  central  canal.  Fig.  81 
shows  these  characters  of  the  flax  fibre.  Characteristic  transverse  markings 
also  are  shown,  which  may  be  nodal  divisions  or  slight  breaks  or  wrinkles 
produced  by  bending.  Longitudinal  fissures  also  show  after  vigorous  rub- 
bing. The  linen  fibre  when  cleansed  has  a  blonde  or  even  white  color,  a  fine 
silky  lustre,  and  great  strength.  It  is  less  pliant  and  elastic  than  cotton  but 
is  a  better  conductor  of  heat,  and  hence  seems  colder  than  cotton.  Chemi- 
cally it  is,  like  cotton,  a  pure  cellulose,  but  when  swollen  by  the  action  of 
ammoniacal  cupric  oxide  solution  does  not  show  the  same  uniform  series  of 


GENERAL   CHARACTERS   OF  VEGETABLE   FIBRES. 


277 


constricting  bands  of  cuticle.  Linen  is  in  many  respects  more  readily  dis- 
integrated than  cotton,  especially  under  the  influence  of  caustic  alkalies, 
calcium  hydrate,  and  strong  oxidizing  agents  like  chlorine  and  hypochlorites. 
3.  HEMP. — The  fibre  known  by  this  name  is  the  product  of  the  Can- 
nabis  sativa,  which  is  grown  for  textile  purposes  chiefly  in  Russia  and  Italy, 
while  the  seed  is  grown  in  India.  It  is  a  bast  fibre  similar  to  that  of  the 
flax-plant,  but  coarser,  stronger,  of  deeper  color  and  less  Juslre.^  Fig.  82 
shows  the  microscopical  characters  of  the  hemp  fibre.  Its  cultivation  is  very 


FIG.  82. 


FIG.  81. 


Flax 


Hemp 


similar  to  that  already  described  under  flax,  and  differs  according  as  the  fibre 
or  the  seed  are  sought.  The  freshly-plucked  hemp  loses  sixty  per  cent,  of 
its  weight  in  drying,  and  from  the  air-dried  hemp  straw  twenty  per  cent,  of 
bast  fibre  is  obtained  in  the  case  of  the  male  plant  and  twenty-two  per 
cent,  in  the  case  of  the  female  plant.  It  is  used  chiefly  for  ropes  and  cord- 
age, and  the  fabric  woven  from  it,  known  as  canvas,  is  used  in  sail-making. 
Much  of  the  finer  fibre,  however,  is  combined  with  linen  fibre  in  weaving 
other  goods.  The  iodine  and  sulphuric  acid  test  shows  that  the  hemp 
fibre  is  not  composed  of  pure  cellulose,  but  is  a  mixture  of  cellulose  and 
bastose. 

4.  JUTE  is  the  bast  fibre  of  two  species  of  the  genus  Corchorus,  and  is 
grown  chiefly  in  India  and  Ceylon.  The  fibre  is  separated  from  the  plant  by 
methods  similar  to  those  employed  with  flax  and  hemp,  the  process  of  cold 
retting  in  stagnant  water  being  followed  generally.  The  bast  fibres  attain  a 
length  of  2.5  metres  or  even  more,  are  of  a  yellowish-white  color,  and  have  a 
fine  lustre.  It  is  seen  under  the  microscope  to  consist  of  bundles  of  stiff 
lustrous  cylinders  with  walls  of  very  irregular  thickness.  These  characters 
of  the  jute  are  shown  in  Fig.  83,  Chemically,  jute  differs  from  the  bast  fibres 


278 


VEGETABLE   TEXTILE   FIBKES. 


FIG.  83. 


Jute,  Corchorus  capsularis  (4f°). 


hitherto  mentioned  in  that  it  contains  no  free  cellulose,  but  consists  of  the 

chemical  compound  of  cellulose  with  lignin,  to  which  Cross  and  Bevan,  who 

investigated  it,  gave  the  name  of  bas- 

tose.  It  gives,  treated  with  iodine  and 

sulphuric  acid,  a  deep  brown  color. 

Moreover,  the  bastose  acts  with  basic 

dye  colors,  like  the  aniline  dyes,  as 

if    it   had    been     mordanted    with 

tannin,  and  can  therefore  be  dyed 

directly  without  previous  treatment. 

It  is  much  more  easily  affected  by 

the  action  of  acids  and  alkalies  than 

flax  or  hemp.     The  influence  of  air 

and  moisture  will  also  rot  the  jute 

fibre.     It  cannot  be  bleached  safely 

with  chloride  of  lime  because  of  the 

readiness  with  which  the  fibre  is  oxi- 
dized, but  it  may  be  bleached  with  a 

weak  solution  of  sodium  hypochlo- 

rite  or  by  the  successive  action  of  po- 
tassium permanganate  and  sulphur- 
ous acid.  It  may  be  considered  as 

showing   more   resemblance   to   the 

animal  fibres  in  lustre  and  appear- 
ance than  any  of  the  other  vegetable 

fibres,  and    is    therefore   frequently 

mixed  with  wool,  mohair,  and  silk  in  certain  classes  of  goods. 

Among  the  fibres  of  lesser  importance  which  serve  as  substitutes  for 

hemp  and  jute  are  Manila  hemp,  Sunn  hemp,  and  Sisal  hemp.     The  first  of 

these  is  a  tropical  fibre,  obtained 
on  the  Philippine  Islands  from 
the  leaves  of  the  wild  plantain. 
The  fibre  is  obtained  by  cutting 
open  the  leaf-stalks,  which  are 
from  six  to  nine  feet  in  length, 
and  then  scraping  them  free 
from  pulpy  matter.  It  furnishes 
a  very  superior  rope-making 
fibre  because  of  its  combined 
lightness  and  strength,  and  the 
finer  grades  are  used  for  woven 
goods.  The  color  is  yellowish 
or  white,  and  the  white  variety 
has  a  fine  silky  lustre.  It  is 
shown  in  Fig.  84. 

The  Sunn  hemp  is  grown 
in  India,  and  furnishes  a  fibre 
of  light-yellowish  color  and  re- 
sembles jute,  although  less  lus- 
Maniia  hemp  ej»).  trous.     It  is  well  adapted  for 

cordage  and  netting. 
Sisal  hemp  (or  henequen)  is  derived  from  the  fleshy  leaves  of  a  species 


FIG.  84. 


GENERAL   CHARACTERS   OF  VEGETABLE   FIBRES. 


279 


FIG  85. 


of  agave  grown  in  Yucatan,  British  Honduras,  and  the  West  Indies  and 
Bahamas.  It  is  used  largely  in  the  United  States  as  a  substitute  for  jute  in 
the  manufacture  of  bagging  and  for  cordage,  being  stronger  and  lighter 
than  jute. 

Ramie  fibre  (China-grass).  —  The  bast  fibre  from  two  varieties  of  Boehm- 
eria  nivea,  known  in  India  as  Rhea,  in  the  Malay  Archipelago  as  Ramie, 
and  to  Europeans  as  China-grass,  has  in  recent  years  attracted  jyery  favor- 
able attention  from  all  interested  in  textile  industries.  It  seems  to  thrive 
best  in  the  tropics  and  requires  a  great  deal  of  moisture.  The  bast  fibre 
cannot  be  removed  from  the  woody  stems  by  the  retting  process  used  for 
flax  and  hemp,  as  the  intercellular  substance  is  so  easily  decomposed  that  the 
water  retting  rapidly  resolves  the  fibre  into  a  magma  of  separated  cells. 
The  fibre  must  be  removed  from  the  woody  stem  while  the  plants  are  in 
the  green  state,  as  when  dried  even  for  several  hours7  exposure  to  the 
sun  the  fibre  becomes  difficult  to  remove  from  the  woody  portion.  The 
length  of  the  cells  makes  it  possible  to  cut  the  ramie  fibre  into  short  lengths 
and  to  treat  the  cleansed  fibre  like  cotton  rather  than  like  a  long  bast  fibre. 
Hence  the  name  "  cottonized"  ramie  which  has  been  applied  to  that  ex- 
ported from  China.  With  improved  methods  it  is  found  possible  to  cleanse 
it  in  full  lengths,  and  the  fibre  is  worked  like  flax  rather  than  with  cotton- 
spinning  machinery.  The  machines  for  breaking  and  decorticating  the 

ramie  are  numerous,  but  few  if 
any  are  entirely  satisfactory.  The 
properly-prepared  fibre  is  of  fine 
silky  lustre,  soft,  and  extraordi- 
narily strong.  It  is  undoubtedly 
the  most  perfect  of  all  the  vege- 
table fibres,  and  will  play  a  great 
part  in  the  industries  of  the  fu- 
ture, especially  as  the  plant,  being 
a  perennial,  can  be  grown  con- 
tinuously for  years,  spreading  of 
itself  very  rapidly  and  yielding 
several  crops  yearly.  Its  culti- 
vation has  been  begun  success- 
fully in  Louisiana  and  Missis- 
sippi, and  it  can  probably  be 
extended  through  the  Southern 
States  and  Mexico,  where  it  has 
also  been  tried.  The  iodine  and 
sulphuric  acid  test  shows  the  ramie 
fibre  to  be  composed  of  a  pure 
cellulose,  which  swells  easily  and 
voluminously  when  treated  with 
ammoniacal  solution  of  cupric 
oxide.  The  appearance  of  the  China-grass  is  shown  in  Fig.  85. 

Nettle  Fibre.  —  The  bast  fibres  of  the  common  nettle  (  Urtica  dioica)  were 
at  one  time  prior  to  the  development  of  the  cotton  industry  used  extensively 
in  spinning  and  weaving  on  the  Continent  of  Europe,  the  cloth  made  being 
known  as  grass-cloth,  the  name  now  given  to  the  product  of  the  China- 
grass,  or  ramie.  The  fibre  when  cleansed  is  soft,  of  good  length  and  strength, 
and  quite  lustrous  and  white.  The  bast  fibres  of  the  linden  (Tilia  Europcea) 


china-grass 


280 


VEGETABLE  TEXTILE   FIBRES. 


and  of  the  paper-mulberry-tree  (Broussonetia  papyri/era)  are  also  used,  the 
former  for  the  manufacture  of  mats  in  Russia  and  the  latter  by  the  paper- 
makers  of  China  and  Japan. 

New  Zealand  Flax  is  a  fibre  obtained  from  the  leaves  of  Phormium 
tenax,  which  acquires  a  length  of  one  to  two  metres.  The  fibre  as  prepared 
by  hand-scraping,  the  method  of  the  native  Maoris,  is  soft,  white,  and  of 
silky  lustre  ;  as  prepared  by  machinery  it  is  distinctly  inferior  in  character. 
Its  chief  value  is  for  rope-making  and  for  coarse  textiles.  The  rope  made 
from  this  fibre  is,  however,  weakened  when  wet  by  sea-water,  and  therefore 
must  be  kept  well  oiled. 

Pineapple  Fibre. — The  leaves  of  the  several  varieties  of  Bromelia  yield 
a  fine,  nearly  colorless,  fibre,  which  is  worked,  especially  in  Brazil,  for  the 
manufacture  of  the  so-called  "  silk-grass." 

Esparto. — This  is  a  grass,  cultivated  especially  in  North  Africa  and 
Spain,  where  ropes  and  cordage  are  made  from  it.  Its  chief  use,  however, 
is  in  connection  with  paper-making.  (See  p.  282.) 

Cocoa-nut  Fibre  (Coir). — The  coarse  fibrous  covering  of  the  nut  of  the 
coco  palm  is  largely  used  for  brooms,  brushes,  matting,  and  coarse  carpet- 
ing. The  fibre  is  coarse,  stiff,  very  elastic,  round,  and  smooth. like  hair. 
It  also  has  great  tenacity,  and  is  well  adapted  for  cordage. 

The  classification  of  the  vegetable  fibres  just  enumerated  has  already 
been  made  upon  the  basis  of  the  iodine  and  sulphuric  acid  reaction  accord- 
ing to  Vetillart.  Two  groups  were  thus  established,  the  one  composed 
essentially  of  unaltered  cellulose  and  the  other  of  lignified  cellulose  bastose. 
Other  reactions  for  these  two  classes  of  materials  are  given  in  the  accom- 
panying table  from  O.  Witt  :* 


Reagent. 

Cellulose. 

Bastose  (compound  of  cellulose  with 
lignin). 

Iodine  and  sulphuric  acid. 
Sulphate    of   aniline    with 
free  sulphuric  acid. 
Basic  aniline  dyes. 
Weak  oxidizing  agents. 
Ammoniacal  cupric  oxide. 

Produces  blue  color. 
Indifferent. 

Indifferent. 
Indifferent. 
Immediate  solution. 

Produces  a  yellow  or  brown  color. 
Colors  deep  yellow. 

Produces  fast  colors. 
Rapid  disintegration. 
Swelling  up,  blue  color,  and  slow 
solution. 

To  distinguish  the  several  more  important  vegetable  fibres  from  er.ch 
other  when  admixed,  a  number  of  chemical  and  physical  tests  have  been 
proposed  in  addition  to  the  microscopical  study  of  the  structural  differences 
already  mentioned  under  the  individual  fibres. 

Thus,  according  to  Kindt's  test,  the  presence  of  cotton  fibre  in  linen 
goods  can  be  distinguished,  after  first  removing  the  size  or  dressing  by 
thorough  boiling  with  distilled  water  and  drying  again,  by  dipping  them 
from  one-half  to  two  minutes,  according  to  the  texture  of  the  goods,  in 
concentrated  sulphuric  acid.  They  are  then  well  washed  with  water, 
rubbed,  dipped  for  a  moment  in  ammon'a-water,  and  dried.  The  cotton 
fibre  is  either  dissolved  or  gelatinized  and  removed  by  the  rubbing,  while 
the  linen  fibre  remains  unchanged  or  but  slightly  attacked.  By  counting 
the  flax  fibres  remaining  for  a  given  superficial  area  the  relative  proportion 
of  cotton  admixture  can  be  determined. 

*  Chem.  Technologic  der  Gespinnstfasern,  p.  111. 


KAW   MATERIALS.  281 

The  different  effect  of  strong  caustic  potash  solution  upon  cotton  and 
linen  fibres  is  also  taken  as  decisive  at  times,  although  the  difference  is  not 
so  marked.  Both  kinds  of  fibres  shrink  in  size,  the  cotton  fibres  remain 
whitish  or  grayish  yellow,  while  the  linen  fibres  are  colored  deep  yellow  or 
orange. 

A  very  characteristic  test  is  that  given  by  Boettger.  A  piece  of  the  mixed 
goods  frayed  out  in  three  sides  is  first  dipped  in  a  one  per  cenk  solution  of 
fuchsine,  then  taken  out,  washed  in  running  water  until  this  runs  off  clear, 
and  dipped  in  ammonia-water  for  from  one  to  three  minutes.  The  cotton 
fibre  is  quickly  decolorized,  while  the  linen  fibre  remains  bright  rose-red  in 
color.  A  test  easily  applied  and  satisfactory  is  the  oil  test,  but  it  is  only 
applicable  to  white  goods  which  are  free  from  size.  The  well-dried  sample 
is  dipped  into  olive  oil,  and  then  well  pressed.  The  linen  fibres  become 
translucent  from  the  capillary  action  upon  the  oil,  while  the  cotton  fibres 
remain  white  and  dull  in  appearance. 

An  alcoholic  cochineal  solution  (one  part  of  powdered  dyestuff  digested 
with  twenty  parts  of  alcohol  of  .847  specific  gravity  for  twenty-four  hours) 
is  also  recommended  by  Bolley.  Cotton  fibres  take  a  clear  red  color  in  this 
solution,  while  linen  fibres  are  colored  violet. 

A  special  test  to  distinguish  the  fibre  of  the  Phormium  tenax  (New  Zea- 
land flax)  from  linen  or  hemp  is  given  by  Vincent.  It  is  in  the  use  of 
concentrated  nitric  acid,  which  colors  the  New  Zealand  flax  distinctly  red, 
but  does  not  change  the  other  fibres  mentioned.  (For  tests  to  distinguish 
the  vegetable  fibres  as  a  class  from  the  animal  fibres,  see  p.  273.) 

The  use  of  the  microscope,  however,  is  much  the  most  reliable  means  of 
distinguishing  the  several  fibres  when  occurring  in  admixtures,  as  the  struct- 
ural character  are  sufficiently  distinct  to  allow  of  easy  recognition  to  those 
possessed  of  some  practice. 

INDUSTRIES    BASED    UPON    THE     UTILIZATION     OF    VEGETABLE 

FIBRES. 

The  great  utilization  of  these  fibres  is  of  course  in  the  manufacture  of 
textile  fabrics  of  all  grades.  Having  dascribed  the  fibres  which  constitute 
the  raw  materials  of  these  industries,  we  shall  pass  the  mechanical  side  of 
their  treatment  and  shall  note  the  chemical  processes  of  bleaching,  dyeing, 
and  color-printing  in  a  later  section  of  the  work  (see  p.  472),  after  the 
preparation  of  natural  and  artificial  dye-colors  has  been  described.  Other 
industries  based  upon  utilization  of  some  one  or  more  of  the  vegetable 
fibres  are  Paper-making,  Pyroxylin  and  Gun-cotton,  Collodion,  Celluloid,  and 
similar  products. 

A.    PAPER-MAKING. 
I.   Raw  Materials. 

1.  RAGS. — The  first  in  order  of  use  for  paper-making  and  still  the  most 
important  raw  materials  for  the  finer  grades  of  paper  are  linen  and  cotton 
rags.  As  the  cellulose  of  these  rags  has  already  undergone  a  process  of 
purifying  from  the  coloring  and  incrusting  matter  with  which  it  was  first 
associated  in  nature  in  its  preparation  for  manufacture  into  textile  fabrics, 
it  is  well  adapted  for  use  in  paper-making,  the  basis  of  which  is  also  a 
cellulose  fibre.  Of  course,  the  rags  may  be  of  all  grades  of  cleanliness. 
They  may  be  cuttings  obtained  in  the  course  of  manufacture  of  garments, 


282  VEGETABLE   TEXTILE   FIBRES. 

and  being  unworn  may  be  relatively  clean,  or  they  may  be  fragments  of 
cast-off  wearing  apparel  gathered  from  waste-heaps  and  reeking  with  filth. 
Indeed,  so  great  is  the  demand  for  paper-making  stock  that  rags  are  gath- 
ered from  Japan,  Egypt,  and  all  parts  of  the  world,  and  the  bales  generally 
require  careful  disinfection  before  they  can  be  used.  They  may  contain 
sizing  and  China  clay  and  other  loading  materials,  or  they  may  be  colored 
with  various  dyes  and  metallic  salts.  Rags  considered  as  paper-making 
stock  must  therefore  be  assorted,  and  for  trade  purposes  they  are  divided 
into  a  large  number  of  grades  or  classes  distinguished  by  different  letters. 

Linen  rags  are  distinctly  superior  for  paper-making  to  cotton  rags,  as 
they  make  a  stronger  and  more  durable  paper. 

2.  ESPARTO. — This  grass,  mentioned  under  the  vegetable  fibres  (see  p. 
280),  is  of  great  importance  as  a  paper-making  material,  particularly  in 
England.     The  Spanish  variety,  according  to  Hugo  Miiller,  contains  48.25 
per  cent,  and  the  African  variety  45.80  per  cent,  of  cellulose,  but  the  yield 
of  bleached  fibre  obtained  in  practice  probably  does  not  much  exceed  forty 
per  cent.     The  fibre  is  tough  and  it  makes  an  excellent  paper,  whether  used 
singly  or  in  admixture  with  other  materials. 

3.  STRAW. — As  a  material  for  admixing  with  other  fibres,  straw-pulp 
is  largely  used.     The  varieties  of  straw  so  utilized  are  oat,  wheat,  rye,  and 
barley.     Of  these,  rye  is  the  most  suitable  on  account  of  its  yielding  the 
largest  amount  of  fibre,  and  next  in  value  is  wheat.     The  amount  of  cellu- 
lose in  whiter  rye  is  given  by  Hugo  Miiller  as  47.69  per  cent,  and  in  win- 
ter wheat  as  46.60  per  cent.,  but  probably  not  more  than  thirty-five  per 
cent,  is  actually  obtained  as  pulp,  much  being  lost  in  the  treatment  on 
account  of  the  loose  aggregation  of  the  cellular  tissue.      Straw  contains 
more  silica  than  Esparto,  and  hence  requires  more  soda  in  the  after-treatment 
to  free  the  cellulose  and  adapt  it  for  use. 

4.  JUTE. — The  "  butts"  or  "  cuttings"  rejected  by  the  textile  manufac- 
turer are  largely  used  in  the  manufacture  of  the  common  grades  of  paper. 
It  possesses  a  large  percentage  of  cellulose  (63.76  per  cent,  in  the  best  fibre 
and  60.89  per  cent,  in  the  "  butts"),  but  it  cannot  be  economically  bleached 
to  a  white  color. 

5.  MANILA  HEMP. — This  is  very  like  jute  in  its  adaptability  for  cheap 
and  colored  papers,  and  as  the  fibre  is  a  lignified  cellulose  it  requires  consid- 
erable boiling  with  soda  to  prepare  it  for  use. 

6.  WOOD  FIBRE. — Two  varieties  of  pulp  for  paper-making  may  be 
obtained  from  wood, — viz.,  mechanically  and  chemically  prepared  pulp. 
Of  these,  the  mechanical  wood-pulp  obtained  by  shredding  the  wood  serves 
for  the  inferior  grades  of  paper  only  as  its  fibres  are  too  short  and  do 
not  "felt"  or  interlace  sufficiently.     It  can  therefore  be  used  only  as  a 
filling  material.     Moreover,  the  resin  present  resists  strongly  the  action  of 
bleaching  agents,  and  the  paper  becomes  yellowish  after  a  time.     On  the 
other  hand,  what  is  termed  chemical  wood-pulp  has  met  with  great  favor  as 
a  very  pure  and  easily  obtainable  form  of  cellulose.     Two  main  processes  for 
its  production  are  now  in  use,  the  caustic  soda  process  and  the  bisulphite 
process.     In  the  former,  the  wood  chopped  up  and  crushed  is  boiled  under 
pressure  with  caustic  soda.     This  is  either  done  in  cylindrical  boilers  at 
pressures  varying  from  four  atmospheres  (sixty  pounds),  as  first  used  by 
Watt  and  Burgess,  to  fourteen  atmospheres  (two  hundred  and  ten  pounds), 
as  used  by  Sinclair,  or  by  lingerer's  graduated  method  in  a  series  of  nine 
connected  vessels,  using  low  pressures  and  partly  saturated  lyes  upon  the 


PEOCESSES   OF  TEEATMENT.  283 

fresh  wood  and  increasing  the  pressure  and  using  fresher  lyes  upon  the 
partly-converted  wood.  From  eighty  to  ninety  per  cent,  of  the  soda  used 
is  recovered  again  from  the  washings.  The  alkali  process  is,  however, 
being  gradually  displaced  by  the  bisulphite  process.  As  first  proposed  by 
Mitscherlich,  acid  calcium  sulphite  was  used.  The  temperature  is  brought 
gradually  to  118°  C.,  which  is  not  exceeded,  the  pressure  being  from  two  to 
three  atmospheres.  In  Ekman's  process  acid  magnesium  sulphite  is  used, 
and  a  pressure  of  from  five  and  a  half  to  six  atmospheres  is  attained.  Still 
another  process  is  that  of  Franke,  which  uses  bisulphite  of  lime  again. 
Cross  and  Bevan  explain  the  efficacy  of  the  bisulphite  processes  by  saying, 
"  The  chief  agency  is  the  hydrolytic  action  of  sulphurous  acid,  aided  by  the 
conditions  of  high  temperature  and  pressure ;  and  the  subsidiary  agencies 
are,  (1)  the  prevention  of  oxidation;  (2)  the  removal  from  the  sphere  of 
action  of  the  soluble  products  of  resolution  in  combination  with  the  sulphite 
as  a  double  compound,  for  it  is  to  the  class  of  aldehydes  that  we  have  shown 
that  the  non-cellulosic  constituents  of  wood  belong ;  and  (3)  the  removal  of 
a  portion  of  the  constituents  in  combination  with  the  base, — i.e.,  with  expul- 
sion of  sulphurous  acid."  The  several  bisulphite  processes,  as  compared  with 
the  ones  mentioned  previously,  yield  a  larger  amount  of  pure  fibre ;  they 
preserve  its  original  strength,  which  is  not  done  when  caustic  soda  acts  upon 
the  loosened  fibre  under  pressure,  and  there  is  a  greater  economy  of  chemicals. 
7.  PAPER-MULBERRY. — In  China  and  Japan,  where  the  paper-makers 
excel  the  best  European  workmen  in  the  making  of  some  delicate  but  strong 
papers,  the  material  chiefly  used  is  the  inner  bark  of  the  papeivmulberry- 
tree  (Broussonetia  papyrifera),  the  leaves  of  which  can  be  used  in  feeding 
silk-worms.  The  strength  of  this  paper  is  due  to  the  fact  that  in  making 
the  pulp  the  long  bast-cells  are  not  broken  and  torn  as  in  European  pulp- 
ing-machines,  but  merely  softened  and  separated  by  beating.  In  taking  up 
the  pulp  in  the  mould  the  cells  are  made  to  lie  in  one  direction,  and  the 
paper  may  be  strengthened  by  taking  one  or  more  dips  in  which  the  cells 
are  made  to  lie  in  other  directions.  Some  gum  is  added  to  make  the  cells 
of  the  pulp  adhere. 

II.   Processes  of  Treatment. 


\ 


1.  MECHANICAL  PREPARATION  OF  THE  PAPER-MAKING  MATERIAL. 

his  differs,  of  course,  according  as  the  raw  material  is  composed  of  rags, 
Esparto,  straw,  or  other  cellulose-containing  substance.  With  rags,  a  pre- 
liminary sorting  always  takes  place,  more  or  less  complete  according  to  the 
make-up  of  the  bales.  Numerous  commercial  designations  are  in  use  for 
these  different  grades  so  obtained.  We  need  only  speak  of  white  linen, 
blue  or  gray  linen,  white  cotton,  colored  linen  or  cotton,  sacking,  half  wool, 
etc.  They  are  then  cut  into  coarse  fragments  by  hand,  being  passed  rapidly 
over  broad  knives  fixed  at  a  set  angle  in  tables,  and  all  buttons  and  hard 
substances  removed.  A  thorough  dusting  or  "  thrashing"  is  now  necessary 
to  remove  the  dust  and  detachable  dirt.  This  is  effected  in  large  wooden 
boxes  with  revolving  arms.  A  more  thorough  cutting  now  ensues  with  the 
aid  of  revolving  knives,  followed  in  most  cases  by  a  final  and  thorough 
dusting,  so  as  to  eliminate  as  much  dirt  as  possible  and  save  in  the  amount 
of  boiling  necessary  as  the  next  operation. 

With  Esparto  a  mechanical  sorting  or  "  picking"  is  also  the  first  opera- 
tion. The  grass  is  spread  out  on  tables  and  the  weeds,  root-ends,  etc.,  care- 
fully removed,  as  these  would  be  difficult  to  boil  and  bleach  and  would  give 


284  VEGETABLE  TEXTILE   FIBEES. 

rise  to  dark-colored  specks  in   the  finished  paper    known  as  "  sheave." 
Machines  for  this  cleansing  of  the  Esparto  are  also  used  quite  largely. 

The  preparation  of  mechanical  and  chemical  wood-pulp  has  already  been 
referred  to. 

2.  BOILING. — The  boiling  of  the  rags  with  caustic  soda,  caustic  lime, 
or  a  mixture  of  soda  ash  and  lime,  which  is  the  next  operation,  is  designed 
to  free  them  from  grease,  dirt,  and  coloring  matter.     This  may  be  done 
either  in  rotating  spherical  or  cylindrical  boilers  or  in  the  so-called  "  vomit- 
ing" boilers  described  later.     The  boilers  are  often  large  enough  to  take 
two  tons  of  rags  at  a  charge.     The  amount  of  alkali  usually  ranges  from 
five  to  ten  per  cent,  on  the  weight  of  the  rags.     Soda  is  preferred  by  many 
paper-makers  to  lime  on  account  of  the  greater  solubility  of  the  compounds 
it  forms,  although  both  are  in  general  use.     The  time  of  boiling  varies  from 
two  to  six  hours,  according  to  the  quality  of  the  rags,  the  alkali  employed, 
and  the  pressure.     The  use  of  high  pressures  is  to  be  avoided  as  far  as  pos- 
sible, as  it  may  result  in  fixing  the  dirt  and  coloring  matter  instead  of  dis- 
solving them.     A  pressure  of  from  three  to  four  atmospheres  is  commonly 
employed.     After  the  pressure  has  been  allowed  to  fall,  the  liquor  collected 
at  the  bottom  of  the  boiler  is  drawn  off  and  water  run  in  to  give  the  rags 
a  slight  preliminary  washing.     The  charge  is  then  drawn  off. 

In  the  case  of  Esparto,  the  "  vomiting"  boiler  or  other  form  of  appara- 
tus for  keeping  up  a  continuous  circulation  of  the  liquor  is  used.  A  form 
of  boiler  in  which  this  circulation  is  kept  up  by  the  use  of  a  steam  injector 
is  shown  in  Fig.  86.  The  grass  is  put  in  through  the  man-hole  Cand  rests 
upon  the  false  bottom  B.  Circulation  is  set  up  by  the  steam  from  the  pipe 
D  passing  through  the  injector  E  and  drawing  the  liquor  through  the  small 
pipe  r.  In  order  that  this  circulation  may  proceed  uniformly,  it  is  neces- 
sary that  the  steam  shall  enter  at  a  pressure  one  atmosphere  higher  than 
the  pressure  existing  in  the  boiler.  A  manometer,  M9  shows  the  pressure, 
and  a  safety-valve,  F,  allows  of  the  adjustment  of  the  necessary  conditions. 
The  contents  of  the  boiler  are  discharged  through  s  at  the  end  of  the  oper- 
ation. The  boiling  takes  from  four  to  six  hours.  The  quantity  of  soda 
necessary  depends  upon  the  nature  of  the  grass,  Spanish  requiring  less  than 
African,  and  the  pressure  employed  varies  from  five  to  forty-five  pounds 
per  square  inch. 

3.  WASHING. — This  operation,  which  must  be  a  thorough  one,  takes 
place  in  a  washer  or  "  breaker."     The  name  "  hollander"  is  very  generally 
given  to  this  machine  as  well  as  to  the  similar  one  in  which  the  beating  or 
mixing  is  done.     The  hollander  is  an  oval  iron  tub,  from  ten  to  twenty 
feet  long,  four  to  six  broad,  and  about  three  feet  high,  divided  for  two- 
thirds  or  more  of  its  length  by  an  upright  partition  known  as  the  "  mid- 
feather."     The  details  of  its  construction  may  be  seen  from  Figs.  87  and 
88.     The  roll  A  carries  upon  its  circumference  a  number  of  steel  knives 
and  revolves  on  one  side  of  the  "  mid-feather,"  or  longitudinal  division 
Q  Q  (Fig.  88).     The  floor  on  this  side  is  raised  in  a  way  as  to  bring  the 
pulp  well  under  the  roll,  as  shown  by  the  line  J OK  (Fig.  87).      Imme- 
diately under  the  roll  is  the  "  bed-plate,"  shown  at  0,  and  provided  with 
knives  similar  to  those  in  the  roll  A,  but  set  with  their  edges  in  the  op- 
posite direction.     The  distance  between  the  roll  and  the  bed-plate  can  be 
varied  at  will  by  means  of  the  hand-wheel  h  and  the  mechanism  shown 
at  k  and  i  (Fig.  88).     After  passing  between  the  roll  and  the  bed-plate, 
the  pulp  flows  down  the  "back-fall"  KK,  and  finds  its  way  around  to  the 


PEOCESSES   OF   TEEATMENT. 


285 


other  side  of  the  mid-feather.  On  the  inclined  part  of  the  floor  and  im- 
mediately in  front  of  the  bed-plate  a  small  depression  is  made  at  E,  covered 
with  an  iron  grating,  for  the  purpose  of  catching  buttons,  small  pieces  of 
stone,  and  other  foreign  substances  that  may  have  found  their  way  into  the 
rags  or  other  paper  stock.  The  dirty  water  from  the  rags  is  removed  by  the 
"  drum-washers"  R  R.  The  ends  of  the  drums  are  of  wood,  and  the  circum- 
ference is  covered  with  fine  copper  or  brass  wire-cloth.  The  ^vash-watel 


passes  through  the  wire-cloth  into  the  compartment  shown  in  R,  and 
passing  towards  the  narrower  end  of  the  inner  conical  tub,  flows  out  through 
the  side  of  the  drum  into  a  trough  placed  to  receive  it. 

In  washing  the  rags  in  this  machine,  the  tub  is  partly  filled  with  water, 
the  rags  from  the  boiler  dumped  in,  and  the  operation  begun.  The  action 
of  the  roll  thoroughly  mixes  pulp  and  water  and  sweeps  the  rags  up  the 
incline  and  over  the  back-fall  K.  The  dirty  water  then  passes  away 
through  the  drum-washer,  the  supply  of  pure  water  being  so  regulated  as 
to  keep  the  level  constant.  When  the  water  begins  to  run  off  clear  the 


286 


VEGETABLE   TEXTILE   FIBRES. 


FIG.  87. 


supply  is  stopped,  the  washer  still  being  kept  in  action.  As  the  level  falls, 
the  drum  is  lowered  by  means  of  the  handle  h.  When  sufficiently  drained, 
the  pulp  is  discharged  through 
the  valves  C  C  in  the  bottom  of 
the  washer.  It  is  now  ready  to 
be  bleached.  This  may  be  done 
in  the  washer  itself  or  in  separate 
engines  called  "potchers."  If 
done  in  the  washer,  a  solution  of 
bleaching-powder  is  run  in  after 
the  withdrawal  of  the  wash- water 
and  the  action  of  the  roll  con- 
tinued. 

Esparto  is  generally  washed 
in  exactly  the  same  way  as  that 
just  described  for  rags,  but  in 
some  mills  the  grass  is  washed 
in  a  series  of  connected  lixivia- 
ting tanks  like  those  used  in  al- 
kali-works. Pure  water  flows 
in  at  one  end,  passes  through 
fresh  lots  of  grass  in  succession, 
and  issues  at  the  farther  end 
highly  charged  with  the  soluble 
products  of  the  grass.  The 
washed  and  broken  pulp  now 
goes  by  the  name  of  "  half-stuff." 

4.  BLEACHING.  —  This  is 
done  with  the  aid  of  chlorine  or 
a  solution  of  calcium  or  sodium 
hypochlorite.  The  use  of  chlo- 
rine gas,  once  largely  practised, 
has  been  almost  entirely  super- 
seded by  the  hypochlorite  solu- 
tions, as  chlorine  is  liable  to  form 
difficultly  removable  compounds, 
and  it  also  tends  to  attack  and 
weaken  the  fibre  of  the  pulp. 
When  chlorine  is  used,  2.5  to  5 
kilos,  of  salt  are  taken  as  needed 
for  100  kilos,  of  "half-stuff." 

The  solution  of  calcium  hypo- 
chlorite must  be  used  perfectly 
clear  and  free  from  undissolved 
hydrate  or  carbonate.  A  solution 
of  6°  Twaddle,  which  contains 
about  half  a  pound  of  bleaching- 
powder  to  the  gallon,  is  com- 
monly used.  An  addition  of  hy- 
drochloric or  sulphuric  acid  to 

the  bleaching-liquor  is  sometimes  made,  but  this  must  be  done  with  care  so 
as  not  to  liberate  chlorine  instead  of  hypochlorous  acid.     This  danger  from 


PROCESSES  OF  TREATMENT. 


287 


FIG.  88. 


288  VEGETABLE  TEXTILE   FIBRES. 

free  chlorine  is  greater  when  highly  lignified  fibres,  such  as  wood  or  jute, 
are  used.  The  bleaching  is  often  effected  by  combining  a  preliminary  treat- 
ment in  the  "  potcher"  or  washer  with  a  subsequent  prolonged  steeping  in 
tanks.  A  process  has  been  recently  proposed  by  Professor  Lunge  involving 
the  use  of  acetic  acid.  The  quantity  required  is  very  small,  as  during  the 
process  of  bleaching  it  becomes  regenerated.  Any  free  lime  in  the  solution 
is  first  nearly  neutralized  with  a  cheaper  acid,  such  as  hydrochloric  or  sul- 
phuric acid,  followed  by  the  addition  of  the  acetic  acid.  The  process  is 
said  by  Cross  and  Bevan  to  give  excellent  results  with  high-class  material, 
such  as  the  best  cotton  and  linen  rags,  but  is  not  to  be  recommended  for 
materials  like  straw  or  Esparto. 

A  process  invented  by  Thompson  is  also  said  to  be  very  effective  for  the 
bleaching  of  rags.  It  consists  in  saturating  the  material  with  a  weak  solu- 
tion of  bleaching-powder  and  then  exposing  them  to  the  action  of  carbonic 
acid  gas.  The  bleaching  action  is  thus  made  very  rapid  and  effective. 

One  of  the  most  recent  innovations  in  bleaching  is  the  application  of 
electricity  in  this  connection.  The  only  process  that  has  yet  attracted  much 
attention  is  that  of  M.  Hermite.  It  is  thus  described  by  Cross  and  Bevan  :* 
"  This  process  is  based  upon  the  electrolysis  of  a  solution  of  magnesium 
chloride,  this  salt  having  been  found  to  give  the  most  economical  results. 
The  solution,  at  a  strength  of  about  2.5  per  cent,  of  the  anhydrous  salt 
(MgCl2),  is  electrolyzed  until  it  contains  the  equivalent  of  about  three  grammes 
of  chlorine  per  litre.  This  solution  is  then  run  into  the  '  potcher7  con- 
taining the  pulp  to  be  bleached ;  a  continuous  stream  is  then  kept  up,  the 
excess  being  removed  by  means  of  a  drum-washer.  This  excess,  which, 
after  being  in  contact  with  the  pulp  in  the  engine,  is  more  or  less  deprived 
of  its  bleaching  properties,  is  then  returned  to  the  el ectroly zing-vat,  where 
it  is  again  brought  up  to  normal  strength.  The  electrolyzed  solution  has 
been  found  to  possess  very  remarkable  properties  which  have  considerable 
bearing  upon  the  economy  of  the  process.  If  a  solution  be  taken  of  equal 
oxidizing  efficiency  with  one  of  calcium  hypochlorite,  as  indicated  by  the 
arsenious  acid  test,  it  is  found  that  the  former  possesses  greater  bleaching 
efficiency  than  the  latter  in  the  proportion  of  five  to  three.  Moreover,  the 
bleaching  is  much  more  rapid  and  the  loss  of  weight  which  the  substances 
undergo  is  less  for  equal  degrees  of  whiteness  obtained."  Further  details 
of  this  process  will  be  found  in  the  article  by  Cross  and  Bevan  in  the 
"Journal  of  the  Society  of  Chemical  Industry,"  for  April,  1887. 

The  removal  of  any  excess  of  chlorine  or  bleaching-liquor  must  now 
be  looked  to.  This  is  done  either  by  careful  washing  or  by  the  use  of  an 
"  antichlor."  The  first  method  has  the  advantage  of  not  only  removing 
the  bleach  but  also  of  the  chloride  of  calcium  which  has  been  formed  from 
it.  It,  however,  takes  some  time  and  consumes  a  large  amount  of  water. 
Much  more  general  is  the  use  of  an  "  antichlor."  The  commonest  of  these 
is  sodium  thiosulphate  (or  hyposulphite,  as  it  is  commonly  called).  This  is 
ordinarily  decomposed  according  to  the  reaction  2(Ca(ClO)2)-fNa2S2O3-f- 
H2O=2CaSO4-|-2HCl-f  2NaCl,  but  when  the  solutions  are  very  dilute, 
sodium  tetrathionate,  Na2S4O6,  and  caustic  soda  and  lime  are  formed.  For 
the  first  equation  two  hundred  and  forty-eight  parts  of  commercial  thiosul- 
phate are  required  to  neutralize  four  hundred  and  nine  parts  of  bleaching- 
powder  of  thirty-five  per  cent,  available  chlorine  strength.  The  various 

*  Text-book  of  Paper-Making,  p.  115. 


PROCESSES  OF  TREATMENT.  289 

sulphites  are  also  in  use  as  antichlors,  sodium  sulphite  being  the  most  im- 
portant. A  cheap  antichlor  is  also  made  by  boiling  together  lime  and 
sulphur,  the  resultant  calcium  sulphide  solution  containing  a  mixture  of 
calcium  thiosulphate  and  calcium  pentasulphide.  This  last-mentioned 
preparation  is,  however,  objectionable  on  account  of  the  free  sulphur 
formed,  as  this  aifects  the  pulp  injuriously.  Whatever  antichlor  is  used, 
an  excess  should  be  avoided,  as  it  may  act  upon  the  color  or  size  added  sub- 
sequently. The  antichlor  should  therefore  be  added  in  successive  small 
portions,  and  any  hypochlorite  solution  still  remaining  be  tested  for  from 
time  to  time  with  iodide  of  starch  paper,  which  will  be  turned  blue  as  long 
as  hypochlorite  remains. 

5.  BEATING. — The  bleached  pulp,  or  "  half-stuff,"  is  not  yet  in  condi- 
tion for  making  an  even  paper,  as  the  fibre  has  not  been  sufficiently  disinte- 
grated.    This  is  now  effected  in  the  beating-engine,  which  is  a  hollander 
very  similar  to  the  breaker  already  illustrated,  except  that  the  roll  carries 
more  knives  and  it  is  usually  let  down  much  nearer  the  bed-plate.     The 
half-stuff  is  furnished  in  successive  portions  to  the  beater  previously  par- 
tially filled  with  water,  each  successive  portion  being  allowed  to  mix  thor- 
oughly with  the  water  before  another  lot  is  added.     This  is  continued  until 
the  mass  is  so  thick  that  it  will  only  just  turn  round  under  the  action  of  the 
roll.     The  operation  of  beating  is  designed  to  be  a  more  complete  breaking 
or  tearing  apart  of  the  fibres  rather  than  a  cutting,  as  this  latter  result 
would  interfere  with  the  felting  of  the  fibres  so  necessary  in  paper-making. 
Cotton  and  linen  rags  naturally  take  longer  than  most  other  paper-making 
material,  taking  often  as  much  as  ten  hours ;  wood-pulp  requires  to  be  very 
gently  and  slowly  beaten,  so  that  it  requires  some  six  hours ;  while  Esparto 
is  sufficiently  disintegrated  in  from  two  to  four  hours.    In  making  the  finer 
grades  of  paper,  the  roller  bars  or  knives  instead  of  being  made  of  steel 
are  made  of  bronze,  so  that  contamination  with  oxide  of  iron  is  avoided. 

Beaters  of  a  totally  different  form  of  construction  are  also  largely  in 
use.  Thus,  in  the  Jordan  beater  the  roll  is  in  the  shape  of  a  truncated 
cone,  fitted  with  knives  and  revolving  in  an  iron  box  of  corresponding 
shape,  and  also  fitted  with  knives  set  at  an  angle.  In  the  Kingsland  en- 
gine and  the  Gould  engine  a  circular  plate  furnished  with  knives  revolves 
against  one  or  more  stationary  plates  similarly  fitted,  somewhat  after  the 
manner  of  millstones.  The  half-stuff  is  even  more  thoroughly  disintegrated 
in  these  beaters  than  in  the  ordinary  forms. 

6.  LOADING,   SIZING,    COLORING,    ETC. — Except  in  the  very   finest 
papers,  some  mineral-loading  material  is  incorporated  with  pulp  when  in 
the  beater.     This  is,  of  course,  in  the  main  for  cheapening  purposes,  but 
also  serves  the  useful  purpose  of  filling  the  pores  of  the  paper  and  enabling 
it  to  take  a  better  surface  in  the  subsequent  operations  of  calendering.     Such 
loading  materials  are  China  clay,  or  kaolin,  sulphate  of  lime,  or  "pearl 
hardening,"  barium  sulphate,  precipitated  chalk,  bauxite,  precipitated  mag- 
nesia, and  magnesium  silicate,  or  "  agalite."    The  amount  added  varies  from 
two  to  three  per  cent,  to  twenty  per  cent.,  or  in  rare  cases  even  more. 

All  papers  except  blotting-papers  have  also  to  be  sized.  This  is  for  the 
purpose  of  filling  the  pores  with  some  material  that  will,  to  some  degree  at 
least,  resist  the  action  of  water.  Thus,  all  writing-papers,  and  in  general 
printing-papers  also,  are  sized  to  prevent  the  ink  applied  to  them  from  run- 
ning. This  is  done  either  by  what  is  termed  "  engine-sizing" — that  is,  in 
the  beating-engine  itself — or  by  "  tub-sizing,"  when  the  paper  as  it  goes 

19 


290  VEGETABLE   TEXTILE   FIBRES. 

through  the  Fourdrinier  machine  (see  below)  passes  through  a  tub  of  gela- 
tine size  and  takes  a  layer  of  the  same  on  either  surface. 

In  "  engine-sizing"  a  rosin  soap  is  first  added  to  the  pulp  in  the  beater, 
and  when  this  is  thoroughly  incorporated  a  solution  of  alum  is  run  in,  form- 
ing, as  it  has  been  generally  supposed,  a  resinate  of  alumina,  which  is  water 
resistant  when  dried.  Wurster  *  claims  to  have  shown,  however,  that  the 
sizing  in  this  case  is  not  due  to  the  formation  of  a  resinate  of  alumina  but  to  a 
separation  of  free  resin,  and  in  this  result  he  has  been  supported  by  Conradin.f 

With  the  resin  soap  is  also  added  some  starch,  and  the  quantity  of  mixed 
rosin  and  starch  is  usually  from  three  to  four  pounds  to  the  one  hundred 
pounds  of  pulp. 

The  pulp  although  bleached  is  rarely  white  enough  to  produce  a  clear 
white  paper,  and  the  yellowish  tint  requires  to  be  neutralized  by  the  addition 
of  small  quantities  of  blue  and  pink  coloring  material.  Ultramarine,  smalt, 
and  aniline-blue  are  used  for  the  first  color,  and  either  cochineal,  Brazil- 
wood, or  aniline-red  for  the  second.  The  paper  may  be  colored  through- 
out any  desired  color  by  using  rags  previously  dyed,  or  by  adding  to  the 
bleached  pulp  in  the  beater  the  necessary  dyes  or  pigments. 

7.  MANUFACTURE  OF  PAPER  FROM  THE  PULP. — We  have  to  con- 
sider here  two  different  products, — viz.,  hand-made  paper  and  machine- 
made  paper.  The  former  is  made  by  taking  in  the  mould  upon  the  "  deckel," 
or  wire-cloth  frame,  just  sufficient  of  the  prepared  pulp  diluted  with  water 
to  make  a  sheet  of  paper.  As  the  water  drains  through  the  wire-cloth  and 
leaves  the  fibres  spread  out  upon  the  surface,  the  felting  operation  is  assisted 
by  shaking  the  frame  gently  from  side  to  side.  The  mould  with  the  sheet 
of  paper  is  then  turned  over,  and  the  sheet  thus  transferred  from  the  wire 
to  a  piece  of  felt.  When  a  number  of  sheets  have  been  thus  prepared,  they 
are  piled  up  with  alternate  sheets  of  felt  and  the  whole  subjected  to  strong 
pressure  to  expel  water.  They  are  then  sized  if  required  by  dipping  them 
into  a  solution  of  gelatine,  again  pressed,  and  hung  up  to  dry.  When  dry 
they  are  calendered  or  pressed  between  hot  metal  rolls. 

Machine-made  paper  is  made  on  what  is  universally  known  as  the 
Fourdrinier  machine,  of  which  an  improved  form,  as  manufactured  by  the 
Pusey  and  Jones  Company,  of  Wilmington,  Delaware,  is  shown  in  Fig.  89. 
We  cannot  here  describe  the  various  mechanical  details  of  this  machine,  but 
may  summarize  by  saying  that  it  consists  of  an  endless  mould  of  wire-cloth 
on  to  which  the  prepared  pulp  flows  from  the  "  stuff-chest'7  through  a  "  regu- 
lating-box" and  over  the  "  sand-table"  and  the  "  screen."  From  the  deckel 
wire  it  now  passes  through  a  series  of  rolls,  at  first  covered  with  felt  and 
later  of  smooth  heated  metal  known  as  the  "  dandy-roll,"  the  "  couch-rolls," 
the  "  press-rolls,"  the  "  drying  cylinders,"  and,  finally,  the  "  calenders."  The 
action  of  the  machine  is  a  continuous  one,  and  the  speed  of  the  Fourdrinier 
is  from  sixty  to  two  hundred  and  forty  feet  per  minute, — the  latter  for  cheap 
newspaper,  the  former  for  the  best  paper  requiring  the  most  care. 

What  is  known  as  "tub-sizing"  is  applied  to  many  machine-made 
papers  in  the  course  of  their  passage  through  the  Fourdrinier.  A  filtered 
solution  of  gelatine  is  used  to  which  about  twenty  per  cent,  of  its  weight 
of  alum  has  been  added.  A  certain  quantity  of  soap  is  also  often  added, 
a  white  soap  free  from  resin  being  used. 

Instead  of  the  Fourdrinier,  what  are  termed  cylinder-machines  are  also 

*  Wagner's  Jahresbericht,  1878,  p.  1155.  f  Ibid.,  1879,  p.  1106. 


PROCESSES   OF  TREATMENT. 


291 


-^ 


292  VEGETABLE  TEXTILE  FIBKES. 

in  use,  in  which  a  large  drum  or  cylinder  covered  with  wire-cloth  revolves  in 
the  vat  containing  the  pulp.  As  it  revolves  the  fibres  attach  themselves  to 
the  wire  and  the  water  is  sucked  through  the  meshes  by  a  partial  vacuum 
within.  The  sheet  of  paper  thus  formed  is  taken  on  to  an  endless  felt  pass- 
ing over  a  couch-roll,  which  revolves  in  contact  with  the  hollow  drum,  and 
thence  passes  to  a  large  drying  cylinder  heated  by  steam.  Paper  made  on 
such  a  machine  is  weaker,  however,  than  that  made  on  the  Fourdrinier, 
because  it  has  not  been  found  possible  to  give  the  shaking  motion  to  the 
cylinder  necessary  to  produce  the  felting  of  the  fibres. 

m.  Products. 

The  products  are  almost  without  number,  and  vary  not  only  in  different 
countries,  but  even  locally  from  time  to  time  as  different  mills  change  their 
production.  We  will  therefore  attempt  only  a  general  classification  of  the 
main  varieties. 

1.  BLOTTING-  AND  TISSUE-PAPER. — These  are  unsized  papers.     Blot- 
ting-paper is  a  mass  of  loosely-felted  fibres,  which,  however,  is  free  from 
any  loading  or  filling  material,  and  therefore  is  capable  of  easily  and  quickly 
taking  up  water  or  other  liquids.     It  may  be  white,  gray,  or  colored  to  any 
shade  by  the  addition  of  the  proper  dyes.     Tissue-papers,  which  as  the 
name  indicates  are  the  thinnest  of  all  papers,  are  made  from  very  strong 
fibres,  such  as  that  of  hemp-bagging  and  cotton  canvas,  and  on  machines 
somewhat  different  from  the  ordinary  Fourdrinier. 

2.  WRAPPING-PAPERS. — These  are  partially-sized   papers   of  coarse 
materials,  such  as  straw,  jute,  Manila  hemp,  common  rags,  ete.     They  may 
show  the  natural  color  of  the  materials  or  may  be  colored,  as  in  the  case  of 
the  blue  wrapping-paper  commonly  used  for  packing  sugar.    A  more  strongly 
sized  and  calendered  wrapping-paper  is  made  for  use  with  linens  and  other 
textile  goods. 

3.  PRINTING-PAPERS. — These  are  white  papers,  generally  with  filling 
and  sizing  material,  although  some  special  grades  are  given  a  smooth  sur- 
face by  calendering  instead  of  sizing.     The  cheaper  grades  for  newspaper 
use  are  frequently  largely  adulterated  with  filling  material,  and  mechanical 
wood-pulp  is  also  largely  used  in  their  manufacture. 

4.  WRITING-PAPERS. — These  are  thoroughly-sized  papers,  for  which  the 
best  materials  are  generally  used,  linen  rags  alone  being  taken  for  the  finer 
grades. 

5.  CARDBOARD,  PASTEBOARD,  AND  PAPIER-MACHE. — Pasteboard  may 
be  made  by  pressing  a  number  of  sheets  of  freshly-formed  unsized  paper  in 
powerful  presses,  or  cementing  them  together  by  the  use  of  glue  or  other 
cementing  material,  and  then  pressing  the  mass  so  formed.     Cardboard  is 
made  direct  upon  machines  adapted  for  heavy  layers  of  pulp  and  pressed 
and  calendered  like  similar  grades  of  ordinary  paper.     Papier-mache  is 
made  chiefly  from  old  paper  by  boiling  to  a  pulp  with  water,  pressing,  mix- 
ing with  glue  or  starch  paste,  and  then  pressing  in  moulds  previously  oiled. 
After  drying,  the  articles  are  soaked  with  linseed  oil  and  then  dried  at 
higher  temperature. 

PARCHMENT-PAPER. — If  a  pure  unsized  paper  be  dipped  in  sulphuric 
acid  of  60°  B.  a  portion  of  the  cellulose  is  changed  into  amyloid  (hydro- 
cellulose,  according  to  Girard),  which  forms  a  gelatinous  coating  over  the 
swollen  fibres  and  effects  in  some  degree  a  sizing  of  them.  The  paper  is 


ANALYTICAL  TESTS   AND   METHODS.  293 

made  hereby  translucent  and  parchment-like,  the  strength  is  increased 
from  three  to  fourfold,  and  the  specific  gravity  by  perhaps  forty  per  cent. 
For  the  manufacture  of  this  parchment- paper  the  long-fibred,  unfilled  paper 
is  to  be  chosen.  After  treatment  the  paper  is  quickly  washed,  first  with 
water,  then  with  weak  ammonia,  and  again  with  water. 

In  place  of  sulphuric  acid  we  have  the  treatment  with  ammoniacal 
cuprous  oxide  solution  or  zinc  chloride.  The  former  reagent  burnishes  the 
Willesden  ware,  which  always  retains  the  light  blue-green  color;  the  latter 
yields  the  valuable  product  known  as  indurated  or  hard  fibre.  In  preparing 
this  latter  material  the  paper,  which  is  either  unsized  or  prepared  with  a 
rosin  size  and  then  nearly  dried,  is  dipped  or  run  while  in  the  roll  through 
a  bath  of  zinc  chloride  of  about  65°  to  70°  B.  kept  at  a  temperature  of 
about  38°  C.  After  passing  through  the  zinc  chloride  bath,  the  paper  is 
passed  over  hot  rolls  and  then  cooled  and  washed  in  pure  water  to  remove 
all  excess  of  zinc  chloride  or  rosin  size.  It  is  then  dried  in  a  heated  room, 
given  a  coating  of  paraffine  oil,  and  calendered.  The  material  so  obtained 
is  very  strong,  tough,  and  can  be  washed. 

6.  SIDE- PRODUCTS. — Recovered  Soda. — The  alkaline  liquors  in  which 
rags,  esparto,  and  other  paper-making  material  have  been  boiled  were  at 
one  time  run  off  as  waste  products.  This  is  no  longer  done  in  properly 
conducted  mills,  as  the  alkali  used  can  be  recovered  in  the  form  of  carbon- 
ate by  evaporation  of  the  waste-liquor  and  ignition  of  the  residues,  and  this 
carbonate  can  then  be  causticized  and  fitted  for  renewed  use.  The  soda 
during  the  process  of  boiling  with  the  paper-making  materials  takes  up  a 
large  amount  of  non-cellulose  fibre  constituents,  such  as  resin,  coloring  mat- 
ter, and  silica.  These  on  evaporation  and  ignition  become  either  carbonate 
or  silicate.  It  will  not  be  possible  for  us  here  to  describe  the  forms  of 
evaporators  in  use  for  this  soda  recovery.  One  of  the  best-known  evapora- 
tors is  that  of  Porion,  used  largely  in  England  and  on  the  Continent.  For 
a  description  of  this  and  other  forms,  see  Cross  and  Bevan's  "  Text-book  of 
Paper-Making,"  p.  182.  The  Yaryan  multiple-eifect  evaporator  (see  p.  131) 
is  also  being  introduced  for  concentration  of  the  spent  liquors. 

The  recovered  soda  consists  essentially  of  carbonate  of  soda,  together 
with  a  certain  amount  of  silicate  of  soda  if  the  liquor  had  been  obtained  by 
boiling  straw  or  Esparto.  The  causticizing  is  done  in  the  usual  way  with 
caustic  lime  and  the  clear  alkali  decanted  from  the  separated  calcium  car- 
bonate, which  is  then  thoroughly  washed. 

IV.  Analytical  Tests  and  Methods. 

1.  DETERMINATION  OF  THE  NATURE  OF  THE  FIBRE. — This  may  be 
done  in  part,  if  not  wholly,  by  either  of  two  methods, — viz.,  by  the  aid  of 
the  microscope  or  by  the  use  of  chemical  tests  for  individual  fibres.  The 
fibre  is  always  torn  or  cut  and  often  somewhat  attacked.  By  some  practice, 
however,  it  is  possible  to  distinguish  between  cotton  and  linen  or  to  identify 
both  in  admixture.  Wood  and  straw  can  also  be  identified.  In  making 
these  tests,  it  is  best  to  take  strips  of  the  paper  in  question  and  boil  them  in 
succession  with  alcoholic  potash  solution,  with  water,  with  two  per  cent, 
hydrochloric  acid,  and  then  again  with  water.  If  they  are  now  shaken  up 
with  a  little  warm  water,  we  obtain  a  fine  magma  of  fibres,  which  when 
mixed  with  an  equal  volume  of  glycerine  is  well  adapted  for  examination 
under  the  microscope.  The  distinctive  characters  of  some  of  the  chief 


294  VEGETABLE  TEXTILE   FIBEES. 

paper-making  materials  as  seen  under  the  microscope  may  be  thus  summa- 
rized, according  to  Cross  and  Bevan  :  *  Cotton,  —  flat,  ribbon-like  fibres,  fre- 
quently twisted  upon  themselves.  The  ends  generally  appear  laminated. 
Linen,  —  cylindrical  fibres,  similar  to  the  typical  bast  fibre.  The  ends  are 
frequently  drawn  out  into  numerous  fibrillse.  Esparto,  —  the  pulp  consists 
of  a  complex  of  bast  fibres  and  epidermal  cells.  The  most  characteristic 
feature  of  Esparto  pulp  is  the  presence  of  a  number  of  fine  hairs  which  line 
the  inner  surface  of  the  leaf,  some  of  which  still  remain  after  the  boiling 
and  washing  processes.  The  presence  of  these  hairs  may  be  taken  as  conclu- 
sive evidence  of  the  presence  of  Esparto.  Straw,  —  this  closely  resembles 
Esparto-pulp  in  microscopical  features,  except  that  the  hairs  are  absent. 
On  the  other  hand,  a  number  of  flat  oval  cells  are  always  present  in  paper 
made  from  straw.  Chemical  wood-pulp,  —  flat  ribbon-like  fibres,  showing 
unbroken  ends.  The  presence  of  pitted  vessels  is  eminently  characteristic 
of  pulp  prepared  from  pine-wood.  Mechanical  wood-pulp  may  be  recog- 
nized by  the  peculiar  configuration  of  the  torn  ends  of  the  fibres  and  from 
the  fact  that  the  fibres  are  rarely  separated,  but  generally  more  or  less  ag- 
glomerated. The  pitted  vessels  of  pine-wood  also  show,  and  usually  more 
distinctly  than  in  chemical  wood-pulp. 

The  chemical  reagent  most  useful  in  testing  paper-pulp  is  aniline  sul- 
phate. With  most  of  the  fibres  which  consist  of  cellulose  simply  it  gives 
no  reaction.  Straw,  Esparto,  and  mechanical  wood-pulp  can,  however,  be 
identified  by  its  means.  Thus,  where  paper  containing  straw  or  Esparto  is 
treated  for  some  time  with  a  boiling  one  per  cent,  solution  of  aniline  sulphate, 
a  pink  color  is  produced.  Esparto  gives  the  reaction  with  greater  intensity 
than  straw.  Mechanical  wood-pulp  treated  with  this  solution  develops  even 
in  the  cold  a  deep-yellow  color.  According  to  Bolley,f  the  moistening  of 
paper  containing  mechanical  wood-pulp  with  nitric  acid  will  give  the  same 
result,  and  a  naphthylamine  salt  produces  a  deeper  orange  color.  Accord- 
ing to  Wiesner,  phloroglucin  is  also  a  delicate  reagent  for  wood  fibre  in 
paper.  A  drop  of  dilute  solution  of  phloroglucin  put  upon  the  paper  and 
this  followed  by  moistening  with  hydrochloric  acid  develops  an  intensely 
red  color.  Fuchsine  also  colors  wood  fibre  red,  but  has  no  eifect  upon 
papep  from  linen  fibre  alone. 

M.  Wurster  in  "  Journ.  de  Pharm.  et  Chemie"  has  extended  Wiesner's 
observation  on  phloroglucin  to  a  number  of  the  phenols,  finding  them  as  a 
class  to  serve  as  reagents  for  distinguishing  between  wood-pulp  and  other 
cellulose.  The  results  are  : 


Reagent.  Wood-pulp. 

Orcin  ..........    .  .   .......  Dark  red.  No  color. 

Resorcin     .    ..............    ."  .  Deep  green.  Violet. 

Pyrogallol  .................  Blue-green.  Violet. 

Phenol    .............    .....  Yellow-green.  Violet. 

Phloroglucin     ...............  Blue-violet.  No  color. 

According  to  Godeffroy  and  Coulon,  mechanical  wood-pulp  from  pine- 
wood  possesses  the  property,  after  it  has  been  extracted  with  water,  alcohol, 
and  ether,  of  reducing  gold  solutions  on  boiling.  This  property  is  not  pos- 
sessed by  wood-pulp  prepared  by  the  caustic  soda  or  sulphite  processes,  after 
similar  extraction  with  solvents,  nor  by  the  pulp  prepared  from  linen  or 

*  Text-book  of  Paper-Making,  p.  199. 

f  Handbuch  der  Technisch-Chem.  Untersuchungen,  6te  Auf.,  p.  1006. 


RAW  MATERIALS.  295 

cotton  fibres.  This  property  depends  upon  the  fact  that  in  mechanical 
wood-pulp  ligno-cellulose  remains,  and  to  this  composition  is  due  the  re- 
ducing power  upon  gold  solutions.  This  ligno-cellulose  is  destroyed  in  the 
preparation  of  chemical  wood-pulp,  and  does  not  exist  at  all  in  the  linen  or 
cotton  fibre.  It  has  been  found  that  on  the  average  one  hundred  parts  of 
mechanical  wood-pulp,  extracted  with  solvents,  and  dried  at  100°  C.,  will 
reduce  fourteen  thousand  two  hundred  and  eighty-five  grammes-of-gold.  It 
is  thus  made  possible  by  weighing  the  reduced  gold  to  estimate  the  amount 
of  mechanical  wood  entering  into  the  composition  of  the  paper.  For  details 
of  the  analytical  method  based  upon  this  gold  reaction,  see  Bolley's  "  Hand- 
buch  der  Technisch-Chem.  Untersuchtmgen,"  6te  Auf.,  p.  1007. 

2.  DETERMINATION  OF  THE  NATURE  OF  LOADING  MATERIALS.  —  The 
total  amount  of  the  mineral-loading  material  is  determined  by  igniting  a 
weighed  quantity  of  the  paper  until  the  ash  is  white  or  grayish  and  then 
accurately  weighing  this.     The  ash  from  a  paper  containing  the  China  clay  is 
insoluble  in  boiling  dilute  hydrochloric  acid  ;  that  from  paper  containing  cal- 
cium sulphate  is  soluble,  and  deposits  on  standing  needle-shaped  crystals  of 
gypsum  easily  recognizable  by  chemical  tests. 

3.  DETERMINATION  AS  TO  NATURE  OF  THE  SIZING  MATERIALS.  — 
The  iodine  test  serves  to  indicate  the  use  of  starch  in  the  size,  as  it  produces 
the  well-known  blue  color.     Extraction  of  the  paper  with  alcohol  contain- 
ing a  few  drops  of  acetic  acid  serves  to  show  the  resin  used  in  the  size.     The 
alcohol,  after  cooling,  is  poured  into  four  or  five  times  its  bulk  of  water, 
when  the  resin  separates,  producing  cloudiness  or  turbidity.     Or,  after  ex- 
traction, the  alcohol  is  evaporated,  leaving  the  resin  capable  of  being  identi- 
fied by  its  properties.     Notable  quantities  of  alumina  in  the  ash  also  point 
to  the  use  of  resinate  of  alumina  as  sizing  material.     According  to  Wurster, 
if  between  two  sheets  of  paper  which  have  been  sized  with  resin  is  pressed 
paper  moistened  with  tetramethylparaphenylen-diamine  solution,  a  bluish- 


violet  color  is  produced,  while  paper  free  from  resin  is  not  affected.  Boil- 
ing of  the  paper  sample  with  distilled  water,  filtering,  and  adding  a  few 
drops  of  tannic  acid  solution  will  serve  to  show  the  presence  of  gelatine 
sizing.  If  present,  a  white  curdy  precipitate  is  formed  on  the  addition  of 
the  tannic  acid. 

4.  DETERMINATION  OF  THE  NATURE  OF  THE  COLORING  MATERIAL. 
—  In  deciding  as  to  the  presence  of  coloring  matter,  we  must  bear  in  mind 
the  reactions  of  the  commoner  pigments  used.  Ultramarine  is  destroyed 
and  decolorized  on  addition  of  acids  ;  Prussian  blue  is  decolorized  by  heat- 
ing with  alkalies  ;  indigo  is  decomposed  by  heating  with  chlorine  or  nitric 
acid  ;  smalt  withstands  the  action  of  both  acids  and  alkalies  and  remains  in 
the  ash  as  a  blue  glass  ;  the  aniline  colors  are  capable  of  extraction  with 
alcohol  as  solvent. 

B.  GUN-COTTON,  PYROXYLINE,  COLLODION,  AND  CELLULOID. 

I.  Raw  Materials. 

The  basis  of  these  preparations  is  the  class  of  nitrates  formed  from  cellu- 
lose by  the  action  of  nitric  acid,  either  taken  singly  or  admixed  with  strong 
sulphuric  acid,  or  as  developed  by  the  action  of  sulphuric  acid  upon  a 
nitrate.  Using  the  doubled  formula  C^H^O^,  we  may  note  the  following 
five  stages  of  nitration  : 

Hexanitrate,  C12H14O4(NO3)6  (trinitro-cellulose,  C6H7(NO2)3O5,  of  other 


296  VEGETABLE  TEXTILE   FIBEES. 

writers),  is  the  true  gun-cotton.  It  is  formed  by  the  action  of  a  mixture 
of  the  strongest  nitric  acid  (specific  gravity  1.52)  with  two  or  three  parts  of 
concentrated  sulphuric  acid,  in  which  the  cotton  is  immersed  for  twenty- 
four  hours  at  a  temperature  not  exceeding  10°  C.  (56°  F.).  The  hexa- 
nitrate  so  prepared  is  insoluble  in  alcohol,  ether,  or  a  mixture  of  both,  in 
glacial  acetic  acid  or  in  methyl  alcohol.  Acetone  dissolves  it  very  slowly. 
According  to  Eder,  the  mixtures  of  nitre  and  sulphuric  acid  do  not  give 
this  nitrate. 

Pentanitrafe,  C12H15O5(NO3)5.  It  is  difficult,  if  not  impossible,  to  pre- 
pare this  nitrate  in  a  state  of  purity  by  the  direct  action  of  the  acid  upon 
cellulose.  The  best  method  (that  of  Eder)  is  to  dissolve  gun-cotton  (hexa- 
nitrate)  in  nitric  acid  at  about  80°  to  90°  C.  (176°  to  194°  F.)  and  then 
precipitate  as  pentanitrate  by  concentrated  sulphuric  acid  after  cooling  to  0° 
C. ;  after  mixing  with  a  larger  volume  of  water  and  washing  the  precipitate 
with  water  and  then  with  alcohol,  it  is  dissolved  in  ether-alcohol  and  again 
precipitated  with  water,  when  it  is  obtained  pure.  This  nitrate  is  insoluble 
in  alcohol,  but  dissolves  readily  in  ether-alcohol  and  slightly  in  acetic  acid. 
Strong  potash  solution  converts  this  nitrate  into  the  dinitrate,  C12H18O8(NO3)2. 

The  tetranitrate  and  trinitrate  (collodion  pyroxyline)  are  generally  formed 
together  when  cellulose  is  treated  with  a  more  dilute  nitric  acid  and  at  a 
higher  temperature  and  for  a  much  shorter  time  (thirteen  to  twenty  minutes) 
than  in  the  formation  of  the  hexanitrate.  It  is  not  possible  to  separate 
them,  as  they  are  soluble  to  the  same  extent  in  ether-alcohol,  acetic  ether, 
acetic  acid,  or  wood-spirit.  On  treatment  with  concentrated  nitric  and  sul- 
phuric acids,  both  the  tri-  and  tetranitrates  are  converted  into  pentanitrate 
and  hexanitrate.  Potash  and  ammonia  convert  them  into  dinitrate. 

The  dinitrate,  C12H18O8(NO3)2,  always  results  as  the  final  product  of  the 
action  of  alkalies  on  the  other  nitrates,  and  also  from  the  action  of  hot, 
somewhat  dilute  nitric  acid  upon  cellulose.  The  dinitrate  is  very  soluble 
in  ether-alcohol,  acetic  ether,  and  in  absolute  alcohol. 

The  chief  raw  material  for  the  manufacture  of  these  nitrates  at  present 
is  the  waste  from  cotton-spinning,  which  has  already  been  freed  from  the 
impurities  of  the  raw  cotton.  It  is  first  picked  clean  by  hand  from  admix- 
ture with  foreign  matter  and  then  torn  and  opened  up  by  machinery  so  as 
to  fit  it  for  easy  action  of  the  nitrating  acids.  It  is  then  treated  for  a  few 
minutes  with  boiling  potash  solution,  thoroughly  washed,  and  dried  by 
steam.  For  the  manufacture  of  celluloid  a  specially  prepared  and  per- 
fectly pure  tissue-paper  is  now  used,  which  is  torn  into  shreds  by  machinery 
preparatory  to  the  nitrating. 

n.  Processes  of  Manufacture. 

1.  GUN-COTTON. — The  following  is  the  procedure  at  Waltham  Abbey, 
where  gun-cotton  is  made  for  the  English  government  under  Sir  F.  AbePs 
improved  method.  A  mixture  of  fifty-five  parts  of  nitric  acid  (1.516 
specific  gravity)  and  one  hundred  and  sixty-five  parts  of  sulphuric  acid  (1.842 
specific  gravity)  is  taken  for  one  part  of  cotton.  The  nitrating  mixture  is 
placed  in  cast-iron  vessels,  cooled  from  without  by  flowing  water,  and  the 
cotton  immersed.  It  may  either  remain  in  these  until  ready  for  washing, 
or  may  after  a  brief  immersion  be  transferred  to  smaller  stone-ware  vessels, 
similarly  cooled,  in  which  it  then  remains  for  twenty-four  hours,  for  the 
double  purpose  of  completing  the  nitration,  so  that  the  product  shall  con- 


PROCESSES   OF   MANUFACTURE.  297 

tain  a  maximum  of  the  highest,  or  hexanitrate,  and  of  allowing  the  contents 
of  the  jar  to  cool  down  perfectly.  The  nitrated  cotton  is  then  "centrifugated, 
stirred  up  thoroughly  with  cold  water,  again  centrifugated,  and  then  washed 
systematically  with  warm  water  to  which  some  soda  has  been  added.  The 
gun-cotton  so  obtained  may  either  be  used  in  the  loose  form  or,  when  de- 
signed for  manufacture  into  cartridges,  is  beaten  in  a  hollander  after  the 
manner  of  paper-pulp,  and  then  washed  and  pressed  in  the  desired  forms. 
The  gun-cotton  when  finished  is  usually  preserved  in  a  moist  state,  and 
dried  only  when  needed  for  use.  It,  however,  does  not  require  to  be  sharply 
dried,  as  with  fifteen  to  twenty  per  cent,  of  moisture  it  can  be  made  to 
develop  its  full  explosive  powers. 

2.  PYROXYLINE  AND  COLLODION. — Pyroxyline  of  various  grades  of 
solubility  can  be  prepared  according  to  the  strength  of  acids  used  and  length 
of  immersion  given  the  cotton.  In  general,  the  nitric  acid  taken  is  less  con- 
centrated than  that  used  for  making  gun-cotton,  and  a  somewhat  higher 
temperature  is  employed.  Potassium  or  sodium  nitrate  is  also  used  along 
with  the  sulphuric  acid  as  the  nitrating  mixture,  as  the  presence  of  nitrous 
acid  in  the  nitric  acid  generated  is  considered  as  playing  some  part  in 
the  result.  A  mixture  of  twenty  parts  pulverized  potassium  nitrate  with 
thirty-one  parts  of  sulphuric  acid  of  1.835  specific  gravity  is  given  as  a  suit- 
able pyroxyline  mixture.  After  the  nitre  has  entirely  dissolved  in  the  sul- 
phuric acid  and  the  mixture  has  fallen  in  temperature  somewhat  below  50° 
C.  the  cotton  is  put  in,  stirred  around  thoroughly,  and  then  the  vessel  left 
covered  for  twenty-four  hours  at  a  temperature  of  from  28°  to  30°  C. 
The  pyroxyline  is  then  washed  with  cold  water  until  it  shows  no  acid  re- 
action, and  finally  with  boiling  water  to  remove  the  last  traces  of  potassium 
sulphate.  A  similar  mixture,  using  sodium  nitrate,  is  thirty-three  parts  of 
sulphuric  acid  of  1.80  specific  gravity,  seventeen  parts  of  sodium  nitrate, 
and  one-half  part  cotton. 

A  special  grade  of  pyroxyline  for  the  manufacture  of  collodion,  put 
upon  the  market  by  the  Schering  factory  in  Berlin,  is  made  by  immersing 
cotton  for  fifteen  minutes  in  a  mixture  of  equal  volumes  of  sulphuric  acid 
of  1.845  specific  gravity  and  nitric  acid  of  1.40  specific  gravity,  taken  at  a 
temperature  of  80°  C. 

The  pyroxyline  made  from  tissue-paper  for  the  celluloid  manufacturers 
is  made  by  taking  fifty  cubic  centimetres  of  nitric  acid  of  1.47  specific 
gravity,  one  hundred  cubic  centimetres  nitric  acid  of  1.36  specific  gravity, 
and  one  hundred  cubic  centimetres  of  sulphuric  acid  of  1.84  specific  gravity. 
In  this  mixture  eighteen  grammes  of  the  finely-shredded  tissue-paper  are 
immersed  at  a  temperature  of  55°  C.  for  one  hour.  The  paper  gains  about 
forty  per  cent,  in  weight  in  the  nitration. 

The  method  of  carrying  out  this  nitration  as  proposed  by  Hyatt,  the 
patentee  of  celluloid,  is  shown  in  the  annexed  illustration.  (See  Fig.  90.) 
The  shredded  paper  is  filled  into  the  container  H,  in  which  has  been  placed 
a  mixture  of  strong  sulphuric  and  nitric  acids  heated  to  from  26°  to  32°  C. 
The  mixture  having  been  vigorously  stirred  by  a  mechanical  stirrer  which 
can  be  raised  and  lowered  at  will,  it  is  allowed  to  remain  at  rest  for  twenty 
minutes  to  allow  of  the  completion  of  the  nitration.  It  is  then  swung 
around  on  the  revolving  table  JET1,  caught  by  a  crane  from  above,  and 
emptied  into  the  centrifugal  K,  which  quickly  drains  off  the  excess  of  acid 
from  the  mass,  the  liquid  flowing  through  the  pipe  Kl  into  the  reservoir  Ol. 
The  container  H  can  be  filled  from  this  reservoir  through  the  pipe  K3  by 


298 


VEGETABLE  TEXTILE   FIBRES. 


the  application  of  air  pressure  at  M9  as  the  lid  of  the  acid  reservoir  is  fitted 
on  air-tight.      O2  is  a  reservoir  for  fresh  acid  mixture. 


FIG.  90. 


The  proportions  of  ether  and  alcohol  used  in  dissolving  pyroxyline  to 
make  collodion  solutions  vary  very  greatly.  The  United  States  Pharmaco- 
poeia prescribes  for  four  parts  of  pyroxyline  seventy  parts  of  stronger  ether 
and  twenty-six  parts  of  alcohol ;  the  British  Pharmacopoeia  takes  for  one 
ounce  of  pyroxyline  thirty-six  fluidourices  of  ether  and  twelve  fluidounces 
of  rectified  spirit ;  the  German  Pharmacopeia  takes  one  part  of  pyroxyline 
to  twenty-one  parts  of  ether  and  three  parts  of  alcohol. 

3.  CELLULOID. — The  conversion  of  pyroxyline  into  celluloid  is  accom- 
plished by  effecting  a  thorough  incorporation  with  the  former  of  a  certain 
amount  of  camphor.  This  may,  however,  be  done  in  a  number  of  ways, 
several  of  which  have  been  carried  out  in  practice.  First,  it  is  possible  to 
effect  it  by  heat  alone,  without  the  use  of  any  solvent  for  either  the  camphor 
or  the  pyroxyline.  The  camphor  at  the  temperature  of  its  fusion  becomes 
a  sufficient  solvent  for  the  pyroxyline  to  effect  complete  physical  admixture. 
This  process  is  essentially  that  used  in  this  country.  The  weighed  amount 
of  camphor  is  added  to  the  pyroxyline  while  the  latter  is  still  in  a  partially 
moist  condition,  some  alcohol  sprinkled  upon  the  mixture  to  aid  in  the  com- 
minution of  the  camphor,  and  the  materials  carefully  ground  together  in  closed 
drums.  The  mixture  may  now  be  put  through  heated  rolls  to  effect  the 
melting  of  the  camphor  and  cause  it  to  penetrate  and  take  up  the  pyroxy- 
line in  every  part  of  the  mass.  It  is  then  put  through  a  heated  masticating 
machine  to  complete  the  admixing  and  make  the  mass  of  uniform  composi- 
tion throughout.  Coloring  matter  is  added  when  desired  to  the  materials 
before  the  camphor  takes  up  the  pyroxyline,  so  that  it  may  be  thoroughly 
distributed  or  dissolved  as  the  case  may  be. 

A  solution  of  camphor  in  either  ethyl  or  methyl  alcohol  has  also  been 
used  as  the  means  of  converting  the  pyroxyline  into  celluloid.  This  may 
be  either  with  the  aid  of  heat  or,  if  sufficient  of  the  solvent  be  used,  it  may 
be  carried  out  at  ordinary  temperatures. 

A  solution  of  camphor  in  ether  has  also  been  used  in  the  celluloid  fac- 
tory of  Magnus  &  Co.  in  Berlin.  For  fifty  parts  of  pyroxyline  is  taken 


PRODUCTS.  299 

twenty-five  parts  of  camphor  dissolved  in  one  hundred  parts  of  ether  to 
which  five  parts  of  alcohol  have  been  added.  The  mixture  is  covered  up 
and  stirred  from  time  to  time.  A  gelatinous  and  glutinous  mass  results, 
which  must  be  rolled  between  calender  rolls  until  it  acquires  plastic  charac- 
ters. The  process  is  distinctly  more  dangerous  than  the  others  mentioned, 
as  the  ether  is  all  allowed  to  evaporate,  and  it  does  not  yield  anything  better 
in  the  way  of  product. 

m.   Products. 

1.  GUN-COTTON. — The  explosive  variety  of  gun-cotton,  whether  in  the 
form  of  loose  fibre  or  as  compressed  cartridge  or  paper  sheets,  cannot  be 
readily  told  by  outward  characteristics  from  untreated  cotton.     Microscopi- 
cally it  has  not  changed.     It  is  on  close  examination  seen  to  be  not  quite  so 
white,  a  slight  yellowish  tint  being  recognizable ;    it  is  slightly  rougher  to 
the  touch,  and  crinkles  slightly  when  pressed  ;  when  rubbed  it  is  easily 
electrified  and  sticks  to  the  fingers.      When  lighted  it  burns  quickly  with- 
out smouldering  or  leaving  any  residue.     When  heated  slowly  it  begins  to 
decompose  with  evolution  of  acid  fumes,  and   above  130°  C.  it  explodes. 
It  is  therefore  necessary  to  exercise  great  care  in  the  drying  of  it,  and  espe- 
cially if  all  traces  of  acid  have  not  been  removed.     It  is  much  safer  when 
wet  than  dry,  although  it  is  possible  to  explode  it  by  concussion  when  it 
still  contains  from  fifteen  to  twenty  per  cent,  of  water. 

Gun-cotton  is  insoluble  in  water,  alcohol,  ether,  chloroform,  and  acetic 
acid,  in  dilute  acids  and  alkalies.  It  is  somewhat  soluble  in  acetone  and 
wood-spirit. 

Gun-cotton  is  chiefly  used  in  submarine  mines  and  blasting  and  for 
naval  torpedoes.  The  combination  of  it  with  nitro-glycerine,  known  as 
blasting  gelatine,  has  been  referred  to  under  another  section.  (See  p.  77.) 

2.  PYROXYLINE. — This  in  most  physical  characters  resembles  perfectly 
the  explosive  gun-cotton.     The  most  important  difference  is  the  ready  solu- 
bility of  this  variety  of  cellulose  nitrate  in  a  mixture  of  alcohol  and  ether, 
in  which  the  true  gun-cotton  is  insoluble.     The  ordinary  pyroxyline  is, 
moreover,  only  slightly  explosive.     When  dissolved  in  the  strength  noted 
before  (see  preceding  page)  we  obtain, — 

3.  COLLODION. — This  is  a  colorless  liquid,  which  rapidly  evaporates  on 
exposure  to  the  air,  leaving  a  transparent  film  of  tetranitrate,  or  tetra-  and 
trinitrate  mixed,  insoluble  in  water  and  alcohol.     It  is  used  as  a  dressing 
for  wounds  under  the  name  of ,"  liquid  adhesive  plaster,"  and  very  largely 
in  photography  as  a  means  of  covering  the   photographic  plates  with  a 
transparent  film  which  shall  hold  finely  divided  and  distributed  the  sensi- 
tive silver  salt. 

4.  PYROXYLINE  VARNISHES. — In  recent  years  a  very  important  class 
of  metal  varnishes  or  lacquers  have  been  introduced  under  trade-names, 
such  as  Zapon  varnish,  etc.,  in  which  pyroxyline  is  the  basis.     This  is  dis- 
solved in  either  methyl  alcohol,  acetone,  methyl  and  amyl  acetates,  or  mix- 
tures of  these.     Petroleum-naphtha  is  also  added  to  these  solvents  to  facili- 
tate the  drying.     These  varnishes  are  of  special  value  for  fine  metal-work 
in  brass  or  bronze,  as  they  leave  a  perfectly  transparent  and  flexible  film 
of  pyroxyline,  which  protects  the  metal  and  will  not  crack  or  peel  when 
properly  applied. 

5.  CELLULOID. — This  valuable  product  of  the  action  of  camphor  upon 
pyroxyline  is  prepared  under  a  great  variety  of  forms,  both  transparent  and 


300  VEGETABLE  TEXTILE  FIBRES. 

opaque,  colored  uniformly,  or  mottled  and  striated  in  imitation  of  ivory, 
coral,  amber,  tortoise-shell,  agate,  and  other  substances.  It  cannot  be  caused 
to  explode  by  heat,  friction,  or  percussion.  When  brought  in  contact  with 
flame  it  burns  with  a  rustling  flame,  and  continues  to  smoulder  after  the 
flame  is  extinguished,  the  camphor  being  distilled  off  with  production  of 
thick  smoke,  while  the  nitro-celliilose  undergoes  incomplete  combustion. 

Celluloid  dissolves  in  warm,  moderately  concentrated  sulphuric  acid,  but 
is  carbonized  by  the  strong  acid.  It  is  readily  soluble  in  glacial  acetic  acid, 
and  on  diluting  the  solution  with  water  both  camphor  and  pyroxyline  are 
reprecipitated.  It  is  rapidly  soluble  in  warm,  moderately  concentrated  nitric 
acid  (four  volumes  of  fuming  acid  to  three  of  water),  and  is  also  dissolved 
with  ease  by  a  hot  concentrated  solution  of  caustic  soda.  Ether  dissolves 
out  the  camphor  from  celluloid,  and  wood-spirit  behaves  similarly.  Ether- 
alcohol  (3:1)  dissolves  both  the  mtro-cellulose  and  camphor,  leaving  the 
coloring  and  inert  matters  as  a  residue.  The  density  of  celluloid  ranges 
from  1.310  to  1.393.  When  heated  to  125°  0.,  it  becomes  plastic  and  can 
be  moulded  into  any  desired  shapes.  Separate  pieces  can  also  be  welded 
together  by  simple  pressure  when  at  this  temperature.  The  celluloid  is 
easily  cemented  to  wood,  leather,  etc.,  by  the  use  of  collodion  or  a  solution 
of  shellac  and  camphor  in  alcohol. 

IV.  Analytical  Tests  and  Methods. 

Pure  hexanitrate  of  cellulose  will  keep  indefinitely,  but  the  presence  of 
free  acid,  of  lower  nitrates,  or  of  fatty  and  waxy  matters  render  it  more  or 
less  unstable,  and  therefore  unsafe.  The  most  important  determinations  to 
make  are  the  examination  for  free  acid  and  for  lower  nitrates,  and  the  valua- 
tion by  means  of  the  estimation  of  NO2  liberated  from  any  sample. 

1.  EXAMINATION  FOR  FREE  ACID. — This  may  be  detected  by  treating 
twenty  grammes'  weight  of  the  gun-cotton  with  fifty  cubic  centimetres  of 
cold  water.     After  twelve  hours  the  water  may  be  pressed  out,  filtered,  and 
twenty-five  cubic  centimetres  titrated  with  decinormal  caustic  alkali.     With 
the  remainder  of  the  liquid  the  nature  of  the  acid,  whether  sulphuric  or 
nitric,  may  be  ascertained  by  the  usual  tests. 

2.  EXAMINATION  FOR  LOWER  NITRATES. — These  may  be  detected  if 
present  by  treating  five  grammes  of  the  sample,  previously  dried  at  100°  C., 
with  one  hundred  cubic  centimetres  of  a  mixture  of  three  parts  of  ether  and 
one  of  alcohol.     The  mixture  is  shaken  frequently  during  twelve  hours,  and 
then  rapidly  filtered  through  loosely-packed  glass-wool,  the  filtrate  evapo- 
rated at  a  gentle  heat,  and  the  residue  weighed. 

3.  EXAMINATION  FOR  UNALTERED  CELLULOSE. — This  may  be  esti- 
mated by  treating  the  gun-cotton  left  undissolved  by  the  ether-alcohol  with 
acetic  ether,  which  dissolves  the  hexanitrate  and  leaves  the  unchanged  cot- 
ton.    An  alternative  plan  is  to  prepare  a  solution  of  sodium  stannite  by 
adding  caustic  soda  to  a  solution  of  stannous  chloride  until  the  precipi- 
tate at  first  formed  is  just  redissolved.     This  solution  when  boiled  with 
gun-cotton  dissolves  the  cellulose  nitrates  without  affecting  the  unchanged 
cellulose.     Sodium  sulphide;  is  also  used  for  the  same  purpose. 

4.  VALUATION  BY  DETERMINATION  OF  NO2. — The  nitrogen  peroxide 
contained  in  gun-cotton  and  similar  nitrated  products  is  frequently  deter- 
mined by  the  aid  of  the  reaction  of  sulphuric  acid  and  mercury  upon  the 
nitrates  as  carried  out  in  a  Lunge's  nitrometer.     This  is  a  burette  provided 


BIBLIOGRAPHY  AND  STATISTICS.  301 

at  the  one  end  with  stopcock  and  funnel-tube  and  narrowed  at  the  other  end, 
which  is  connected  by  a  stout  piece  of  rubber  tubing  with  a  simple  gradu- 
ated burette-tube.  The  burette  with  the  stopcock  is  filled  with  mercury 
through  the  rubber  connection  with  the  other  tube  and  the  stopcock  closed. 
.35  gramme  of  gun-cotton,  dissolved  in  five  cubic  centimetres  of  concen- 
trated sulphuric  acid,  are  then  put  into  the  funnel-tube,  and  by  opening  the 
stopcock  and  lowering  slightly  the  connecting  burette  are  drawn  rato  the 
stoppered  tube,  washed  out  of  the  funnel  with  a  little  additional  pure  sul- 
phuric acid,  and  the  stopcock  closed.  The  tube  is  then  shaken  vigorously 
until  the  reaction  is  complete  and  the  volume  of  gas  no  longer  increases. 
It  is  then  allowed  to  attain  constant  temperature  and  the  volume  read  off  with 
correction  for  temperature  and  pressure.  Allen  (Commercial  Organic  Anal- 
ysis, 2d  ed.,  vol.  i.  p.  328)  recommends  that  the  volume  be  compared  with 
that  yielded  by  a  standard  sample  or  a  nitre  solution. 


V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1873. — Die  G-espinnstfasern,  R.  Schlesinger,  Zurich. 

Die  Pflanzenfasern,  Hugo  Miiller,  Leipzig. 
1874. — Etude  sur  le  Travail  des  Lins,  A.  Kenouard,  Paris. 
1876. — Etudes  sur  les  Fibres  vegetales  textiles,  M.  Vetillard,  Paris. 

1877. — Die  Pflanzenfasern,  Hugo  Miiller  (and  Hofmann's  Entwickelung  der  Chem.  Ind.), 
Braunschweig. 

Die  Fabrikation  des  Papiers,  L.  Miiller,  Berlin. 
1878.— Cotton  from  Seed  to  Loom,  William  B.  Dana,  New  York. 
1881. — Matieres  premieres  organiques,  G.  Pennetier,  Paris. 

Die  Gewinnung  der  Gespinnstfasern,  H.  Richard,  Braunschweig. 
1882.— Structure  of  the  Cotton  Fibre,  F.  Bowman,  Manchester. 

The  Manufacture  of  Paper,  Charles  T.  Davis,  Philadelphia. 

Chevallier's  Dictionnaire  des  Falsifications,  Baudrimont,  Paris. 

Etude  sur  les  Textiles  tropicaux,  A.  Renouard,  Lille. 
1884. — Ueber  pflanzliche  Faserstoffe,  F.  von  Hohnel,  Wien. 

Ramie,  Rhea,  Chinagras  und  Nesselfaser,  Bouche  und  Grothe,  Berlin. 

Cotton-Spinning,  R.  Marsden,  London. 

Guide  pratique  de  la  fabrication  du  Papier,  A.  Proteaux,  Paris. 
1885. — The  Dyeing  of  Textile  Fabrics,  J.  J.  Hummel,  London. 
1886. — Handbuch  der  Papierfabrikation,  S.  Mierzinski,  Wien. 

The  Manufacture  of  Paper,  Charles  T.  Davis,  Philadelphia. 
1887. — Report  on  Indian  Fibres  and  Fibrous  Substances,  Cross  and  Bevan,  London. 

Die  microskopische  Untersuchung  des  Papiers,  J.  Wiesner,  Leipzig. 

Die  Fabrikation  des  Papiers,  Egbert  Hoyer,  Braunschweig, 

Microscopie  der  Faserstofte,  F.  von  Hohnel,  Wien. 

The  Practical  Paper- Maker,  J.  Dunbar,  3d  ed.,  London. 
1888. — A  Text-Book  on  Paper-Making,  Cross  and  Bevan,  London. 

Die  chemische  Technologie  der  Gespinnstfasern,  Otto  Witt,  Braunschweig. 

Die  Jute  und  ihre  Yerarbeitung,  E.  Pfuhl,  Bd.  i.,  Berlin. 

Papier  priifung,  W.  Herzberg,  Berlin. 

1890. — Report  on  Flax,  Hemp,  Ramie,  etc.,  United  States  Department  of  Agriculture, 
Washington,  D.C. 

The  Cotton  Fibre,  its  Structure,  etc.,  Hugh  Monie,  Jr.,  Manchester. 

The  Art  of  Paper-Making,  Alex.  Watt,  London. 
1892.— Die  Cellulose  Fabrikation,  Max  Schubert,  Berlin. 

Explosives  and  their  Powers,  M.  Bethelot,  trans,  by  Hake  and  McNab,  London. 

Index  to  Literature  of  Explosives,  C.  E.  Munroe,  Washington. 

Taschenbuch  fur  den  praktischen  Papier  Fabrikanten,  C.  F.  Dahlhehn,  2te  Auf., 

\  i  i 

Munchen. 
1893.— Textiles  Vegetaux,  E.  Lecompte,  Paris. 

Examen  microscopique  des  textile  fibres,  R.  Schlesinger,  traduit  par  L.  Gautier, 
Paris. 


302 


VEGETABLE  TEXTILE   FIBRES. 


1893.— Modern  High  Explosives,  M.  Eissler,  3d  ed.,  New  York. 
1894.—  Das  Celluloid,  Dr.  Fr.  Bockmann,  2te  Auf.,  Wien. 

The  Chemistry  of  Paper-Making,  Griffin  and  Little,  New  York. 
1895. — Cellulose,  Cross  and  Bevan,  London  and  New  York. 

Die  Baumwolle,  Th.  Otto  Schweitzer,  Bern. 

A  Treatise  on  Paper-Making,  C.  Hoffman,  New  York. 

The  Manufacture  of  Explosives,  O.  Guttmann,  2  vols.,  New  York. 
1896.— Nitro-Explosives,  P.  Gerald  Sanford,  London. 
1897. — Hand-Book  of  Modern  Explosives,  M.  Eissler,  2d  ed.,  London. 

A  Treatise  on  Paper,  R.  Parkinson,  3d  ed.,  London. 
1898.— Cotton,  its  Uses,  Varieties,  Fibre,  etc.,  C.  P.  Brooks,  Lowell  and  New  York. 

The  Technical  Testing  of  Yarns  and  Textile  Fabrics,  J.  Herzfeld,  trans,  by  Charles 

Salter,  London. 
1900. — Die  Eohstoffe  der  Pflanzenreiches,  J.  Wiesner,  2te  Auf.,  Leipzig. 


I.    a.       PRODUCTION,    CONSUMPTION 


STATISTICS. 

AND    EXPORTATION 
STATES. 


OF    COTTON    FROM    THE    UNITED 


YEAR. 

Production. 

Domestic  con- 
sumption. 

Exportations. 

Value  of  expor- 
tations. 

Pounds. 

Pounds. 

Pounds. 

Dollars. 

1894-95   . 
1895-96  .... 
1896-97   .... 
1897-98  .... 
1898-99   .... 

5,036,964,409 
3,592,416,851 
4,397,177,704 
5,677,259,827 
5,794,767,917 

1,519,431,300 
1,257,190,466 
1,293,422,755 

1,826,995,532 
2,006,848,795 

3,517,433,109 
2,335,226,385 
3,103,754,949 
3,850,264,295 
3,773,410,293 

204,900,990 
190,056,460 
230,890,971 
230,442,215 
209,564,774 

(Statistical  Abstract,  United  States  Treasury  Department. ) 


i.  b.     WORLD'S  SUPPLY  AND  CONSUMPTION  or  COTTON. 
(Bales  of  500  pounds.) 


1894-95. 

1895-96. 

1896-97. 

1897-98. 

1898-99. 

Crop  of  the  United  States  

9,640,000 

6,912,000 

8,435,000 

10,890,000 

11,189,205 

Crop  of  other  countries  

1,625,000 

1,938,000 

1,924,000 

1,665,000 

2,342,464 

Total  crop  

Consumption  in  United  States    .... 
Consumption  in  Great  Britain    .... 
Consumption  on  Continent  
Consumption  in  India    

11,265,000 

2,743,000 
3,250,000 
4,030,000 
1,074,000 

8,850,000 

2,572,000 
3,276,000 
4,160,000 
1,105,000 

10,359,000 

2,738,000 
3,224,000 
4,368,000 
1,004,000 

12,555,000 

3,002,000 
3,406,000 
4,485,000 
1,075,000 

13,531,669 

3,553,000 
3,519,000 
4,836,000 
1,297,000 

World's  consumption  

11,097,000 

11,113,000 

11,334,000 

11,968,000 

13,205,000 

II.  FLAX. — According  to  a  United  States  consular  report  from  Odessa 
(United  States  Consular  Reports,  March,  1891,  p.  365),  the  total  area 
sown  in  Europe  with  flax  amounted  to  5,700,000  acres,  of  which  Russia 
alone  had  3,700,000  acres.  The  total  quantity  of  flax  fibre  produced  in 
Europe  is  there  given  as  follows  : 


Pounds. 

Russia 900,000,000 

Austria-Hungary    ....  104,400,000 

Germany 97,200,000 

France 79,200,000 

Ireland 46,800,000    ( 


Pounds. 

Belgium 43,200.000 

Italy 43,200,000 

All  other  countries  .    .    .        36,000,000 


1,350,000,000 


BIBLIOGRAPHY   AND   STATISTICS. 


303 


In  1898  the  amount  of  flax  fibre  produced  in  Europe  was : 


Pounds. 

Russia 1,530,776,000 

Austria-Hungary    .    .    .      114,097,000 

Italy 41,917,000 

Belgium 32,246,000 

France 25,126,000 


Pounds. 
Netherlands.    .  .    .       12,934,000 

Sweden 4,223,000 

Servia 1,237,000 


Total 1,762,556,000 


III.  JUTE. — The  exportations  of  jute,  etc.,  from  Calcutta  and  Chit- 
tagong  in  recent  years  have  been  : 


YEAK. 

Jute. 

Rejections. 

Cuttings. 

Total. 

1890-91 

Bales. 

2,640,821 

Bales. 
51,459 

Bales. 
524,250 

Bales. 
3,216,530 

1891-92 

1,714,063 

21,733 

209,054 

1,944,480 

1892-93                       .    .    . 

2,549,634 

40,924 

411,884 

3,002,442 

1893  94               

2,151.344 

50,  151 

206,102 

2,407,577 

1894-95               

2,969,627 

55,  792 

436,803 

3,462,222 

(Textile  Manufactures,  June  15,  1895.) 

IV.  IMPORTATIONS  OF  VEGETABLE  FIBRES. — The  importations  of 
unmanufactured  vegetable  fibres  into  the  United  States  during  the  last  few 
years  have  been  as  follows : 

1896. 

7,833 
$1,804,428 

55,694 
$4,674,088 

88,992 
$2,001,206 

52,130 


Flax  (tons) 

Valued  at 

Hemp  and  substitutes  (tons) 

Valued  at 

Jute  (tons) 

Valued  at 

Sisal-grass,  etc.  (tons) 


Valued  at $3,412,760 


1897. 

1898. 

1899. 

9,190 

5,529 

6,474 

$1,897,976 

$1,193,597 

$1,306,520 

51,380 

54,287 

57,136 

$4,048,179 

$3,799,675 

$6,688,583 

68,550 

112,306 

83,161 

$1,640,484 

$2,543,498 

$2,296,189 

63,266 

69,322 

71,898 

$3,834,732 

$5,169,900 

$9,211,377 

V.  PAPER  AND  PULP  STATISTICS. — 

Paper-making  Materials. — The  importations  of  paper  stock  for  the  last 

three  years  have  amounted,  according  to  the  United  States  Bureau  of 
Statistics,  to : 

1897.  1898.                         1899. 

Kags  other  than  woollen  (pounds)  .    .51,181,009  49,800,209          55,596,560 

Valued  at $668,385  $699,981             $805,545 

All  other  stock  valued  at $2,403,320  $2,170,342          $1,809,369 

Wood-pulp  (tons)       41,770  29,846                 33,319 

Valued  at $800,886  $601,642             $671,506 


The  English  importations  of  paper-making 
three  years  have  been  : 

1897. 
Linen  rags  (tons) 25,333 

Valued  at  .    .    .  - £249,631 

•Esparto  (tons) 204,579 

Valued  at £825,195 

Wood-pulp  (chemical  tons)  ....  "1 

Valued  at I        388,304 

Wood-pulp  (mechanical  tons) .    .    .    (£1,939,761 

Valued  at  . 


materials  during  the  last 


1898. 

20,559 

£193,803 

197,341 

£768,779 

179,510 

£1,226,026 

225, 3f^ 

£668,302 


20,617 

-£174,661 

207,604 

£806,354 

196,926 

£1,441,809 

218,180 

£547,897 


According  to  "  Bradstreet's"  for  November  29,  1890,  the  American 
output  of  wood-pulp  more  than  trebled  within  ten  years.     There  were 


304  VEGETABLE  TEXTILE  FIBRES. 

then  210  factories  engaged  in  its  manufacture, — 183  producing  it  by  the 
mechanical  process,  15  by  the  soda,  and  12  by  the  sulphite  methods. 

According  to  a  report  made  to  the  United  States  Department  of  Labor 
in  1898,  there  were  in  the  first  half  of  1898,  723  paper  and  pulp  manufac- 
turers having  altogether  1067  mills.  Of  the  723  manufacturers,  644  re- 
ported their  production  for  the  half-year,  amounting  to  994,087  tons  of 
paper  and  619.383  tons  of  pulp.  The  value  of  the  paper  was  $48  689,880, 
and  of  the  pulp,  $13,428,542;  together,  $62,118,422.  The  States  with 
largest  production  were  Massachusetts,  New  York,  Maine,  Wisconsin,  and 
Pennsylvania.  Almost  one-third  of  the  paper  production — viz.,  311,898 
tons — was  used  for  the  daily  newspapers.  The  production  of  colored  paper 
amounted  to  124,339  tons;  of  wood-fibre  Manila  paper,  72,073  tons;  of 
cardboard,  70,694  tons ;  and  of  Manila  papers,  760,383  tons.  The  61 9,383 
tons  of  pulp  were  made  up  of  367,744  tons  of  ground  wood-pulp,  173,420 
tons  of  sulphite  pulp,  74,379  tons  of  soda  pulp,  and  3840  tons  of  cotton 
fibre. 

Reckoning  on  the  production  of  this  half-year,  and  counting  in  the  79 
establishments  not  reporting,  the  annual  production  of  the  United  States 
is  estimated  at  about  $105,000,000  of  paper  and  $28,500,000  of  pulp. 
The  figures  in  the  census  year  1890  were  $72,773,093  for  paper  and 
$5,1 52,038  for  pulp. 

The  total  export  from  Norway  of  moist  machine  wood-pulp  has  been 
as  follows  in  recent  years  :  In  1889,  190,000  tons  ;  in  1890,  207,000  tons ; 
in  1891,  230,000  tons;  in  1892,  215,000  tons;  in  1893,  230,000  tons;  in 
1894,  240,000  tons.  The  value  of  the  1894  exportation  was  from  9,500,000 
to  10,000,000  krona  (1  krona  =  $0.26.8). 

The  exportation  of  chemical  wood-pulp  from  Norway  was,  for  1893, 
32,000  tons  of  dry  and  13,000  tons  of  moist  pulp;  for  1894,  34,000  tons 
of  dry  and  10,000  tons  of  moist  pulp.  The  value  was  between  6,000,000 
and  6,500,000  krona. 


KAW   MATERIALS. 


305 


CHAPTER  IX. 


TEXTILE    FIBRES   OP   ANIMAL   ORIGIN. 

As  before  stated,  the  only  animal  fibres  that  have  acquired  technical 
importance  are  the  wool  fibre  and  silk.  These  will  now  be  considered. 

I.  Raw  Materials. 

A.  WOOL. — Wool  is  undoubtedly  a  variety  of  hair,  found  in  greater  or 
less  quantity  on  almost  all  mammals,  on  a  few  of  which,  as  the  domestic 
sheep,  it  forms  the  principal  covering  of  the  body.  It  is  probable  that 
while  both  hair  and  wool  occur  together  in  wild  sheep,  domestication  has 
gradually  caused  the  rank  hairy  fibres  to  disappear  and  the  soft  under-wool 
to  develop  until  the  fleece  of  wool  becomes  a  thick  and  complete  covering. 
From  ordinary  hair  the  wool  is  distinguished  by  two  important  properties : 
First,  while  hair  is  almost  smooth  on  the  surface,  the  wool  fibre  is  covered 
by  minute  overlapping  scales  arranged  like  roof-tiles.  While  these  scales 
are  so  minute  as  not  to  be  discernible  to  the  eye,  they  can  be  felt  if  a 
woollen  fibre  is  drawn  between  the  fingers  in  the  direction  opposite  to  that 

in   which   the    scales    are    set. 

Fio.  91.  Secondly,  while  a  hair  is  per- 

fectly straight,  the  woollen  fibre 
is  finely  crimped  or  curled,  so 
that  it  becomes  longer  when 
drawn  out  and  shortens  again 
when  the  strain  is  removed. 
The  spring  due  to  this  curled 
structure  gives  woollen  fabrics 
notable  elasticity.  Owing  to 
the  overlapping  scale-like  struc- 
ture and  the  crimped  condition 
of  the  fibre,  wool  has  -also  the 
power  of  felting,  or  becoming 
matted  into  a  compact  cloth 
under  the  fulling  process  with- 
out the  necessity  of  weaving. 
These  structural  characters  of 
the  wool  fibre  are  shown  in 
Fig.  91. 

Sheep's  wool  varies  from 
the  long  straight  coarse  hair  of 
certain  varieties  of  the  English 

sheep's  wool  (af°).  sheep  (Leicester,    Lincolnshire, 

etc.)  to  the  comparatively  short 

wavy  fine  soft  wool  of  the  Spanish  and  Saxon  Electoral  sheep.  According 
to  the  average  length  of  the  fibres  or  staples  two  principal  classes  of  wool 
are  established,  the  long-stapled  (eighteen  to  twenty-three  centimetres)  and 

20 


306  TEXTILE  FIBRES  OF  ANIMAL  OKIGIN. 

the  short-stapled  wools  (two  and  five-tenths  to  four  centimetres).  The 
former  class  have  hitherto  been  combed  and  then  spun  into  worsted  yarn, 
while  the  latter  have  been  carded  and  spun,  yielding  woollen  yarns.  These 
processes  will  be  referred  to  again  later.  (See  p.  314.)  In  general  the  long 
straight  wools,  like  Lincoln  and  Leicester  wools,  possess  a  silky  lustre,  and 
are  known  as  lustre  wools,  while  the  Merino,  Colonial,  etc.,  which  are  shorter 
and  curly,  are  known  as  non-lustre  wools. 

The  worth  of  any  grade  of  wool  is  determined  by  noting  such  proper- 
ties as  softness,  fineness,  length  of  staple,  waviness,  lustre,  strength,  elas- 
ticity, flexibility,  color,  and  the  facility  with  which  it  can  be  dyed.  Wool 
is  very  hygroscopic.  In  warm  dry  weather  it  may  contain  eight  to  twelve 
per  cent,  moisture,  but  if  kept  for  a  time  in  a  damp  atmosphere  it  may  take 
up  thirty  to  fifty  per  cent.  This  becomes  an  important  item  in  the  sale  of 
wool,  and  hence  in  France  and  Germany  the  percentage  of  moisture  con- 
tained in  wool  to  be  sold  must  be  officially  determined  in  "  wool-condition- 
ing" establishments.  (See  silk-conditioning,  p.  311.)  The  legal  amount 
of  moisture  allowed  on  the  Continent  is  18.25  per  cent. 

The  best  kind  of  wool  is  colorless,  but  inferior  grades  are  often  yellow- 
ish, and  sometimes  even  brown  or  black  in  color. 

The  chemical  composition  of  the  wool  fibre  is,  as  already  noted  (see  p. 
273),  nitrogenous,  but  we  must  at  the  same  time  distinguish  between  the 
true  fibre  and  the  encrusting  matters.  These  latter,  independent  of  me- 
chanically adhering  impurities  or  "dirt,"  are  of  twofold  character,  the 
"wool-fat"  (soluble  in  ether)  and  the  "wool-perspiration"  (soluble  in  water). 
These  two  are  frequently  included  together  under  the  name  of  the  "  yolk" 
or  "  suint"  of  the  wool.  The  true  wool  fibre,  when  cleansed  from  these, 
has  approximately  the  following  composition :  Carbon,  49.25  per  cent. ; 
hydrogen,  7.57  per  cent.;  oxygen,  23.66  per  cent;  nitrogen,  15.86  per 
cent. ;  sulphur,  3.66  per  cent.  The  presence  of  sulphur  is  very  distinctive 
of  wool  and  serves  to  distinguish  it  from  silk,  the  other  nitrogenous  fibre. 
It  can  be  removed  in  large  part,  but  not  without  weakening  the  fibre  and 
destroying  its  lustre,  etc. 

Wool-fat  is  a  mixture  of  a  solid  alcoholic  body,  cholesterine,  together 
with  isocholesterine  and  the  compounds  of  these  bodies  with  several  of  the 
fatty  acids.  These  free  higher  alcohols  are  soluble  in  boiling  ethyl  alcohol, 
while  the  compounds  they  form  with  the  fatty  acids  are  insoluble  in  alcohol 
but  soluble  in  ether. 

Wool-perspiration  has  been  shown  to  consist  essentially  of  the  potassium 
salts  of  oleic  and  stearic  acids,  possibly  other  fixed  fatty  acids,  also  potas- 
sium salts  of  volatile  acids,  like  acetic  and  valerianic  acid,  and  small  quan- 
tities of  chlorides,  phosphates,  and  sulphates.  The  wash-water  of  raw  or 
greasy  wool,  it  will  be  seen,  therefore,  would  contain  large  amounts  of 
potash  salts,  and  when  evaporated  and  ignited  would  yield  an  abundant 
product  of  potassium  carbonate.  This  utilization  of  the  wool  wash- water 
as  carried  out  at  present  in  France  and  Belgium  yields  over  one  million 
kilos,  of  potassium  carbonate.  Another  utilization  of  this  yolk  of  wool  is 
to  submit  it  to  dry  distillation,  when  it  yields  a  residue  which  is  an  ex- 
tremely intimate  mixture  of  carbonate  of  potash  and  nitrogenous  carbon, 
of  great  value  for  the  manufacture  of  yellow  prussiate  of  potash. 

^  Wool  is  decomposed  by  heat  at  130°  C.,  ammoniacal  vapors  are  given 
off,  and  at  140°  to  150°  C.  sulphur  compounds  are  also  present  in  the 
vapors.  When  ignited  by  a  flame,  wool  emits  the  disagreeable  odor  of 


RAW  MATERIALS. 


307 


burnt  feathers  and  leaves  a  porous  caked  residue.  Ammoniacal  solution  of 
cupric  hydrate  has  no  action  upon  wool  in  the  cold,  but  dissolves  it  when 
hot.  Dilute  solutions  of  hydrochloric  and  sulphuric  acids  have  little  in- 
fluence whether  hot  or  cold.  This  fact  is  availed  of  in  separating  cotton 
from  wool  in  the  process  of  "  carbonizing"  mixed  cotton  and  woollen  goods. 
The  dilute  sulphuric  acid  used  attacks  and  disintegrates  the  cotton.  They 
are  then  dried  in  closed  chambers  at  110°  C.,  after  which  the  disorganized 
cotton  can  be  beaten  out,  while  the  wool  remains  but  slightly  altered. 
Nitric  acid  does  not  attack  the  wool  seriously,  but  gives  it  a  yellow  color, 
hence  sometimes  used  as  a  "  stripping"  agent  for  dyed  woollen  goods  in 
case  of  re-dying.  Sulphurous  acid  is  the  most  satisfactory  bleaching  agent 
for  woollens,  as  it  removes  the  natural  yellow  tint  of  the  ordinary  wool. 
Caustic  alkalies  act  rapidly  and  injuriously  upon  wool.  Alkaline  carbonates 
and  soap  have  little  or  no  injurious  action  if  not  too  concentrated  and  if 
the  temperature  is  not  above  50°  C.  Chlorine  and  hypochlorites  act  injuri- 
ously upon  wool  and  cannot  be  used  for  bleaching.  A  very  slight  action 
of  chlorine,  on  the  other  hand,  causes  wool  to  assume  a  yellowish  tint  and 
gives  it  an  increased  affinity  for  many  coloring  matters. 

Closely  related  to  sheep's  wool  are  a  few  varieties  of  animal  hair,  which 
are  also  utilized  in  some  degree  as  textile  fibres  in  similar  classes  of  goods. 

Mohair  is  the  product  of  the  Angora  goat  of  Asia  Minor  and  Cape  Col- 
ony, South  Africa.     It  is  a  long  silky  hair,  which  is  very  soft  and  lustrous. 
Cashmere  consists  of  the  soft  under- wool  which  grows  in  winter  on  the 
Cashmere  goat.     It  furnishes  the  material  for  the  costly  Cashmere  shawls 
of  native  manufacture,  but  is  not  exported  at  all  as  fibre. 

Alpaca,  Vicuna ,  Llama,  and  Guanaco  are  the  names  of  four  closely- 
related  species  of  South  American  goats  found  on  the  western  slopes  of  the 

Andes,  which  yield  valuable  hair-like  fibres. 
Of  these,  the  alpaca  is  exported  in  largest 
amount  to  Europe  and  the  United  States.  It 
is  a  long  silky  fibre  somewhat  intermediate  be- 
tween true  wool  and  hair  and  possessing  a  strong 
lustre.  It  is  both  white  and  of  various  colors. 
It  is  shown  in  Fig.  92. 

Camel's  Hair  is  somewhat  used  in  Africa, 
Asia  Minor,  and  the  Caucasus,  and  latterly  in 
Europe,  for  the  manufacture  of  woven  goods, 
which  are  made  from  the  unbleached  hair. 

B.  SILK. — The  silk  fibre  is,  morphologi- 
cally, the  simplest  and  at  the  same  time,  because 
of  its  properties,  the  most  perfect  of  the  textile 
fibres.  It  differs  from  all  other  fibres  in  that 
it  is  found  in  nature  as  a  continuous  fine  thread, 
so  that  the  process  of  spinning  is  superfluous  in 
its  case.  In  place  of  this  we  have  the  reeling 
process,  whereby  several  of  the  natural  threads 
are  united  into  one  thicker  and  stronger  thread. 
Silk  is  the  product  of  the  silk-worm  (Bom- 
byx  mori)  and  is  simply  the  fibre  which  the 
worm  spins  around  itself  for  protection  when 
entering  the  pupa  or  chrysalis  state.  From  the 
eggs  laid  by  the  animal  in  the  moth  or  butterfly  state  develops  the  cater- 


FIG.  92. 


Alpaca  goat's  hair  (3f°). 


308 


TEXTILE  FIBRES  OF  ANIMAL  ORIGIN. 


pillar  or  silk-worm.  The  eggs  are  yellowish  in  color  at  first,  changing  to 
gray  when  dry.  They  are  very  light  in  weight,  some  thirteen  hundred  and 
fifty  together  weighing  one  gramme.  For  the  development  of  the  cater- 
pillar from  them  a  certain  amount  of  warmth  and  moisture  is  necessary,  the 
temperature  being  raised  in  the  incubation  chamber  during  ten  or  twelve 
days  from  18°  to  25°  C.  The  young  worms  are  at  once  removed  to  larger 
chambers,  where  are  lath  frame-works  strung  across  with  threads  and  sheets 
of  paper.  The  animals  are  placed  upon  these,  and  fed  regularly  during 
thirty  to  thirty-three  days,  till  indeed  they  begin  to  spin.  They  are  here 
fed  upon  mulberry  leaves  (Morus  alba),  and  during  this  period  increase 
enormously  in  size,  becoming  at  length  about  eight  to  ten  centimetres  long 
and  about  five  grammes  in  weight.  To  allow  of  this  increase  in  size  it 
casts  its  skin  some  four  times  during  this  period  (at  intervals  of  from  four 
to  six  days).  When  about  the  thirtieth  day  of  its  growth  has  been  reached 
it  ceases  to  take  food  and  shows  a  decided  restlessness.  It  is  then  placed 
on  birch-twigs,  and  soon  begins  to  spin.  This  spinning  of  the  cocoon,  or 
oval-shaped  house  in  which  the  worm  is  to  undergo  the  chrysalis  state  before 
emerging  as  the  butterfly,  in- 
volves the  secretion  of  the  fibre  FIG.  94. 
so  much  prized  as  silk.  The 
silk  substance  is  secreted  by 
two  glands,  one  on  either  side 
of  the  body  of  the  caterpillar. 
The  substance  from  these  two 
glands  unites  in  a  capillary 
canal  situated  in  the  head  of 
the  animal,  whence  issues  the 
silk  as  a  double  fibre  only 


Fia.  93. 


Silk  fibre  ( 


rarely  separated,  cemented  throughout  by  the  sericin,  or  silk-glue.      The 
microscopical  appearance  of  the  silk  fibre  is  shown  in  Fig.  93.     This  fibre 


RAW  MATERIALS.  309 

which  goes  to  form  the  cocoon  varies  in  length  from  three  hundred  and  fifty 
to  twelve  hundred  and  fifty  metres,  and  with  a  diameter  of  about  .018 
millimetre  in  diameter.  The  interlacing  layers  of  the  silk  cocoon  are  at 
first  loose,  but  become  finer  and  denser  towards  the  interior,  while  the  inner- 
most layer  which  immediately  surrounds  the  animal  forms  a  thin  parch- 
ment-like skin.  The  several  stages  of  cocoon-spinning  are  shown  in  Fig. 
94.  The  cocoons  of  the  female  are  pure  oval  in  shape,  whilaJhose  of  the 
male  are  distinctly  contracted  in  the  centre.  They  are  white  or  yellowish, 
and  usually  about  three  centimetres  long  and  one  and  one-half  to  two  centi- 
metres thick.  Some  seven  or  eight  days  are  allowed  for  the  completion  of 
the  cocoon-spinning,  and  they  are  then  gathered.  A  sufficient  number  of 
both  males  and  females  are  taken  for  breeding  purposes,  and  the  rest  put 
aside  to  be  reeled  for  silk.  Those  chosen  for  breeding  are  kept  for  some 
twenty  days  at  a  temperature  of  from  19°  to  20°  C.,  when  the  silk-moth 
which  has  formed  in  the  interior  from  the  pupa  emits  a  peculiar  saliva, 
which  softens  the  sericin,  or  silk-glue,  at  one  end  of  the  cocoon  and  enables 
the  animal  to  push  its  way  out  to  daylight.  The  females  within  forty  hours 
after  their  appearance  lay  their  eggs,  some  four  hundred  in  number,  and 
shortly  after  die.  The  eggs  are  slowly  dried,  and  stored  in  glass  bottles  in 
a  dry  dark  place  till  the  following  spring.  The  cocoons  put  aside  for  the 
reeling  of  silk  must  be  taken  in  hand  promptly  and  the  chrysalis  contained 
in  them  killed,  in  order  to  prevent  the  development  of  the  silk-moth  and 
the  injury  to  the  cocoon  by  its  pushing  its  way  out.  This  is  done  either  by 
heating  them  for  several  hours  in  an  oven  at  60°  to  70°  C.,  or  more  quickly 
by  steam  heat.  One  hundred  grammes  of  eggs  produce  under  favorable 
conditions  from  ninety  thousand  to  one  hundred  and  seventeen  thousand 
cocoons,  weighing  one  hundred  and  fifty  to  two  hundred  kilos.,  and  these 
yield  twelve  to  sixteen  kilos,  of  reeled  silk. 

The  silk  fibre  consists  to  the  extent  of  rather  more  than  half  its  weight 
of  fibroin,  C15H23N5O6,  a  nitrogenous  principle.  Covering  this  is  the  silk- 
glue,  or  sericin,  C^H^NgOg.  Whether  this  latter  exists  in  the  glands  of 
the  silk-worm  along  with  the  fibroin,  as  maintained  by  Duseigneur-Kleber, 
or  is  produced  exclusively  by  atmospheric  change  from  the  fibroin  as 
asserted  by  Bolley,  is  still  in  debate.  This  sericin,  however,  is  easily 
dissolved  off  from  the  fibroin  by  warm  soap-water  and  other  alkaline 
liquids.  This  "  boiled-off "  liquid  plays  an  important  part  in  silk-dyeing 
operations.  (See  p.  491  )  The  most  important  physical  properties  of  the 
silk  fibre  are  its  lustre,  strength,  and  avidity  for  moisture.  The  regu- 
lation of  the  amount  of  moisture  contained  in  raw  silk  as  offered  for  sale, 
or  "  silk-conditioning,"  will  be  spoken  of  under  the  process  of  treatment. 
(Seep.  311.) 

Besides  the  true  silk,  the  product  of  Bombyx  mori,  we  have  several 
so-called  "  wild  silks,"  the  most  important  of  which  is  the  Tussur  silk, 
the  product  of  the  larva  of  the  moth  Anthercea  mylitta,  found  in  India. 
The  cocoons  are  much  larger  than  those  of  the  true  silk-worm,  egg- 
shaped,  and  of  a  silvery  drab  color.  They  are  also  attached  to  the  twigs 
of  the  food  trees  by  a  thread-like  prolongation  of  the  cocoon.  The 
cocoon  is  very  firm  and  hard,  and  the  silk  is  of  a  drab  color.  It  is  used 
for  the  buff-colored  Indian  silks,  and  latterly  largely  in  the  manufacture 
of  silk  plush.  Other  wild  silks  are  the  Eria  silk  of  India,  the  Muga 
silk  of  Assam,  the  Atlas  or  Fagara  silk  of  China,  and  the  Yama-mai  silk 
of  Japan. 


310  TEXTILE  FIBRES  OF  ANIMAL  ORIGIN. 


n.  Processes  of  Manufacture. 

It  will  be  beyond  the  province  of  this  work  to  take  up  the  manufacture 
of  woollen  and  silk  goods  from  the  mechanical  side.  Hence  we  shall  only 
notice  the  preliminary  processes  of  chemical  treatment  which  the  fibres 
undergo  to  prepare  them  for  manufacture  into  goods,  and  then  take  up  the 
several  classes  of  manufactured  textiles  again  in  speaking  of  bleaching  and 
dyeing  of  goods. 

A.  WOOL. — 1.  Wool-scouring. — The  condition  of  the  raw  wool  when  first 
obtained  from  the  back  of  the  sheep  has  already  been  referred  to.  The  fibre 
is  covered  with  both  natural  and  artificial  impurities  (yolk,  dirt,  etc.)  to 
such  an  extent  that  mordanting  and  dyeing  would  be  almost  impossible. 
These  are  therefore  to  be  removed  by  the  process  of  scouring.  It  will  be 
remembered,  too,  that  the  yolk  was  stated  to  be  made  up  of  the  wool-fat 
(soluble  in  alcohol)  and  the  wool-perspiration  (soluble  in  water).  Both  of 
these  have  to  be  removed  in  the  completed  scouring  operation.  The  full 
operation  then  must  include  three  stages, — viz.,  steeping,  or  washing  with 
water  (desuintage) ;  cleansing  or  scouring  proper  with  weak  alkaline  solu- 
tions (degraissage)  •  rinsing  or  final  washing  with  water  (ringage).  The 
first  operation  may  be  omitted  if  the  wool  has  been  washed  by  the  wool- 
grower.  This  is  true,  for  instance,  with  Australian  wools,  while,  on  the 
other  hand,  most  South  American  wools  come  into  commerce  unwashed  and 
very  rich  in  yolk.  The  washing  of  these  wools  is  largely  carried  on  in 
France  and  Belgium,  and,  as  has  been  stated  (see  p.  306),  is  made  to  yield 
large  amounts  of  potassium  carbonate  by  evaporating  and  igniting  the  wash- 
waters.  The  wool  is  systematically  washed  in  tepid  water  (about  45°  C.) 
in  a  series  of  tanks  arranged  so  that  the  water  passes  from  one  to  the  other 
until  completely  saturated,  when  it  is  evaporated.  According  to  M.  Chan- 
delon,  one  thousand  kilos,  of  raw  wool  may  furnish  three  hundred  and 
thirteen  litres  of  yolk  solution  of  specific  gravity  1.25  (50°  Tw.),  having  a 
value  of  fifteen  shillings  and  sixpence,  while  the  cost  of  extraction  does 
not  exceed  two  shillings  and  sixpence. 

The  scouring  and  washing  processes  for  loose  wool  are  usually  carried 
out  in  the  well-known  rake  scouring-machines,  consisting  of  a  large  cast- 
iron  trough  provided  with  an  ingenious  system  of  forks  or  rakes  whereby 
the  wool  is  gradually  passed  forward  by  the  to-and-fro  digging  motion  of 
the  rakes.  Two  or  three  such  scouring-machines  are  placed  in  series,  so 
that  the  first  may  take  the  bulk  of  the  impurities,  the  second  complete  the 
scouring,  and  the  third  effect  a  thorough  washing  in  a  stream  of  fresh  water. 
The  scouring  liquid  which  has  been  longest  in  use  is  stale  urine  (lant), 
which  is  effective  because  of  the  ammonium  carbonate  it  contains.  It  is 
now  largely  supplanted  by  ammonia,  sodium  carbonate,  soaps,  etc.  The 
most  injurious  effects  arise  from  the  use  of  water  containing  lime  or  mag- 
nesia, because  of  the  formation  of  the  insoluble  lime  or  magnesia  compounds 
upon  the  fibre.  In  recent  years  volatile  solvents,  like  fusel  oil,  ether,  petro- 
leum-naphtha, carbon  disulphide,  have  also  been  introduced  for  scouring 
purposes,  although  not  generally  adopted  on  account  of  the  expense  and 
risk  attending  their  use.  They  must  be  followed  at  all  events  by  a  washing 
with  water,  as,  while  they  dissolve  fatty  matters,  they  do  not  take  up  the 
oleates,  etc.,  of  the  wool-perspiration. 

The  only  treatment  of  this  kind,  known  technically  as  a  degreasing 


PEOCESSES   OF  MANUFACTUEE.  311 

process,  is  that  with  petroleum-naphtha.  This  has  been  found  practicable 
and  remunerative.  The  wool,  freed  from  its  grease  and  wax-like  con- 
stituents by  the  naphtha  and  its  potash  salts,  by  a  washing  with  water  only 
is  left  in  an  excellent  condition  for  the  mechanical  treatment,  such  as  card- 
ing and  combing. 

Woollen  yarns  and  woollen  cloth  are  also  scoured  to  free  them  from  the 
oil  which  has  either  purposely  or  by  accident  been  put  upon  them  in  the 
spinning  and  weaving  operations.  The  scouring  of  "  union"  goods — that 
is,  materials  with  cotton  -warp  and  woollen  weft — is  a  more  difficult  opera- 
tion on  account  of  the  differences  in  elasticity,  hygroscopic  character,  etc.,  of 
the  cotton  and  the  wool  fibre.  It  includes  the  operations  of  crabbing,  steam- 
ing, and  scouring. 

2.  Bleaching  of  Wool. — Wool  is  generally  bleached  either  as  yarn  or 
cloth.  The  bleaching  agent  in  general  use  is  sulphur  dioxide.  It  may  of 
course  be  applied  either  as  gas  or  as  sulphurous  acid  solution,  the  former 
method  being  generally  followed,  and  the  yarn  or  cloth  suspended  on  poles 
in  closed  chambers,  called  sulphur-stoves,  which  can  be  charged  with  the 
gas.  In  liquid  bleaching  with  sulphurous  acid,  a  solution  of  sodium  bisul- 
phite is  generally  used,  which  is  either  mixed  with  an  equivalent  amount  of 
hydrochloric  acid  or,  what  is  better,  the  goods  are  passed  through  one  solu- 
tion after  the  other  in  separate  baths.  The  bleaching  of  sulphur  dioxide 
differs  essentially  from  that  effected  by  chlorine  and  hypochlorites  in  that  it 
is  not  due  to  oxidation,  but  to  reduction  or  possibly  to  the  formation  of  color- 
less compounds  with  the  natural  yellow  color  of  the  wool.  At  all  events,  it 
is  not  permanent  in  character,  and  the  yellow  color  gradually  returns  on  ex- 
posure to  atmospheric  influences  and  repeated  washings  in  alkaline  solutions. 

The  best  liquid  bleaching  agent  is  hydrogen  dioxide.  The  woollen  mate- 
rial is  steeped  for  several  hours  in  a  dilute  and  slightly  alkaline  solution  of 
the  commercial  H2O2  and  then  well  washed,  first  with  water  acidified  with 
sulphuric  acid  and  afterwards  with  pure  water. 

B.  SILK. — 1.  Reeling <  of^Silk. — The  unwinding  of  the  long  silk  fibre  from 
the  cocoon  and  bringing  it  into  condition  for  weaving  is  to  be  accomplished 
in  the  reeling  process.  The  cocoons  are  thrown  into  a  basin  of  warm  water 
to  soften  the  silk-glue  and  allow  of  the  fibres  being  separated.  From  four 
to  eighteen  fibres,  according  to  the  quality,  are  taken,  and  two  threads  formed 
by  passing  the  fibres  together  through  two  perforated  agate  guides.  After 
being  crossed  or  twisted  together  at  a  given  point  they  are  again  separated 
and  passed  through  a  second  pair  of  guides,  thence  through  the  distrib- 
uting guides  on  to  the  reel.  The  temporary  twisting  or  crossing  causes  the 
agglutination  of  the  individual  fibres  of  each  thread.  In  order  to  form 
long  threads  a  frequent  adding  on  the  fibre  of  a  new  cocoon  is  necessary. 
Care  must  be  taken,  also,  that  the  thread  remain  as  nearly  as  possible  of  uni- 
form thickness,  so  that  as  the  inner  fine  fibres  of  several  cocoons  come 
through  the  guides  another  cocoon  is  added  to  the  number  used  for  the 
thread.  One  cocoon  gives  .16  to  .20  or  at  most  .25  gramme  of  raw  silk.  The 
loss  through  removal  of  the  external  floss  varies  from  eighteen  to  thirty  per 
cent.,  according  to  the  cocoons  and  the  care  bestowed  by  the  worker.  Before 
this  raw  silk  can  be  used  for  weaving  two  of  the  threads  are  "  thrown" 
together  and  slightly  twisted. 

2.  Silk-conditioning. — Raw  silk  kept  in  a  humid  atmosphere  is  capable 
of  absorbing  thirty  per  cent,  of  its  weight  of  moisture  without  this  being 
at  all  perceptible.  It  therefore  becomes  a  matter  of  great  importance  for 


312 


TEXTILE   FIBKES   OF   ANIMAL   ORIGIN. 


FIG.  95. 


the  buyer  to  know  what  weight  of  normal  silk  there  is  in  any  given  lot. 
To  ascertain  this  with  accuracy,  there  have  been  established  in  a  number  of 
the  European  centres  of  silk  industry  conditioning  establishments.  The 
operation  is  carried  out  by  means  of'  the  apparatus  shown  in  Fig.  95,  where 
a  number  of  hanks  of  silk  are  shown  in  the  drying  chamber.  A  test  hank 
of  silk  is  taken  from  the  bale,  and  having  been  suspended  from  the  one  arm 
of  an  accurate  balance  its  initial  weight  is  gotten.  It  is  then  dried  in  a  cur- 
rent of  air  at  110°  C.  until  constant  weight  is  again  obtained.  The  arrange- 
ment of  the  drying  chamber  is  shown  in 
the  illustration.  To  the  final  weight  ob- 
tained for  the  dry  silk  eleven  per  cent,  is 
added,  and  the  result  taken  as  a  normal 
silk  weight.  The  average  loss  of  weight 
in  this  conditioning  process  is  about 
twelve  per  cent. 

3.  Silk-scouring. — By  the  scouring 
of  silk  the  silk-glue  is  removed  to  a 
greater  or  less  extent  and  the  fibre  is 
rendered  lustrous  and  soft  and  able  to 
take  the  dye-color.  According  to  the 
amount  of  silk-glue  removed  in  this 
operation  the  product  is  called  boiled-off 
silky  souple  silk,  or  £cru.  In  the  first 
case,  the  loss  of  silk-glue  amounts  to 
twenty-five  to  thirty  per  cent,  of  the 
weight  of  the  raw  silk  ;  in  the  second, 
to  eight  to  twelve  per  cent. ;  and  in  the 
third  to  three  to  four  per  cent,  of  the 
original  weight  of  the  silk.  In  preparing 
the  first  variety  two  operations  are  neces- 
sary, stripping  or  ungumming  (degom- 
mage)  and  boiling  off. 

The  hanks  of  raw  silk  are  suspended 
by  wooden  rods  in  a  rectangular  trough 
lined  with  copper  and  worked  by  hand  in  a  thirty  to  thirty-five  per  cent, 
soap  solution  heated  to  90°  to  95°  C.  When  the  water  is  very  hard  it 
must  be  corrected  or  softened  previously.  Frequently  two  soap-baths  are 
used  one  after  the  other  as  the  first  one  becomes  charged  with  the  silk- 
glue.  The  silk  at  first  swells  up  and  becomes  glutinous,  but  as  the  glue 
dissolves  off  it  becomes  soft  and  silky.  The  waste  soapy  and  glutinous 
liquid  obtained  is  called  "  boiled-off"  liquor,  and  is  a  useful  addition  to 
the  dye-bath  in  dyeing  with  coal-tar  colors.  (See  p.  491.)  For  the  pur- 
pose of  removing  the  last  portions  of  the  silk-glue,  it  is  now  washed  in 
water  at  60°  C.,  to  which  some  soap  and  carbonate  of  soda  have  been  added, 
then  put  in  coarse  hempen  bags  called  "  pockets"  and  boiled  for  half  an 
hour  to  three  hours,  according  to  quality,  in  open  copper  vessels  with  a  so- 
lution of  ten  to  fifteen  per  cent,  of  soap.  It  is  then  rinsed  with  a  weak 
tepid  solution  of  sodium  carbonate,  and  finally  washed  in  cold  water.  Silk 
intended  to  remain  white  or  to  be  dyed  pale  colors  is  then  at  once  bleached 
while  moist  with  gaseous  sulphur  dioxide  for  some  six  hours.  The  bleach- 
ing operation  may  be  repeated  from  two  to  three  times,  according  to  the 
quality  of  the  silk. 


PROCESSES   OF   MANUFACTURE.  313 


Sonple  silk  is  that  which  has  been  prepared  for  dyeing  with  a  IOPS  of 
not  more  than  eight  per  cent,  of  its  weight.  It  is,  however,  not  so  strong 
as  boiled-off  silk,  and  is  used  only  for  tram.  Its  preparation  always  in- 
cludes two  operations,  and  if  the  silk  is  to  be  dyed  light  colors,  two  addi- 
tional operations  have  to  be  carried  out.  The  raw  silk  is  first  "  softened," 
and  the  small  quantity  of  fatty  matter  present  removed  (degraissage)  by 
working  it  from  one  to  two  hours  in  a  ten  per  cent,  soap  "sokrtien  at  25° 
to  35°  C.  It  is  then  "  bleached"  by  immersion  for  ten  to  fifteen  minutes 
in  a  dilute  solution  of  aqua  regia  (five  parts  hydrochloric  acid  to  one 
part  nitric),  or  as  a  substitute  for  this  nitrated  sulphuric  acid  (nitrosyl-sul- 
phate).  This  is  followed  by  "  stoving,"  or  treatment  with  sulphur  dioxide, 
and  then,  without  removing  the  sulphurous  acid,  by  the  treatment  of  sou- 
pling  (assouplissage)  proper.  This  consists  in  working  the  silk  for  about 
an  hour  and  a  half  at  90°  to  100°  C.  in  water  containing  three  to  four 
grammes  cream  of  tartar  to  the  litre.  This  treatment  makes  the  silk  softer 
and  causes  it  to  swell  up  and  become  more  absorbent.  It  is  then  finally 
washed  in  tepid  water. 

ficru  silk  is  raw  silk  which  has  been  washed  with  hot  water,  with  or 
without  soap,  bleached  with  sulphur,  and  again  washed.  It  is  only  used 
for  a  base  for  other  silk  fabrics  like  velvet  or  dyed  in  blacks. 

B.  1.  ARTIFICIAL  SILK.  —  In  1888  Chaidonnet  first  brought  to  the 
attention  of  the  textile  trade  a  product  obtained  from  cotton  by  a  peculiar 
treatment,  to  which  the  name  of  "  artificial  silk"  was  given,  because  of  its 
similarity  in  lustre  and  general  appearance  and  its  capability  of  readily 
taking  all  shades  of  color  when  dyed,  and  of  being  woven  into  fabrics  as 
beautiful  if  not  quite  as  strong  and  durable  as  the  natural  product  of  the 
silk-worm.  This  product  is  now  manufactured  on  a  large  scale  at  Besan9on 
in  France,  in  Belgium,  and  in  Germany,  and  has  become  an  article  of 
commerce. 

The  raw  material  is  cotton  lint  carded  into  wadding.  This  is  trans- 
formed into  nitro-<  ellulose  by  immersion  in  a  mixture  of  fifteen  parts  of 
nitric  acid  of  1.52  specific  gravity  and  eighty-five  parts  of  commercial 
sulphuric  acid.  The  immersion  continues  until  a  sample  on  examination 
under  the  microscope  with  polarized  light  shows  a  clear  blue  color  only. 
The  nitrated  cotton  is  then  pressed,  to  free  it  from  excess  of  acid,  and 
washed  until  the  last  trace  of  acid  is  removed.  After  compression,  it  is 
taken  with  thirty-three  per  cent,  of  moisture  still  remaining  and  dissolved 
by  digestion  in  autoclaves  in  a  mixture  of  equal  parts  of  ninety-five  per 
cent,  alcohol  and  ether.  The  solution  after  filtering  through  lint  cotton  is 
set  aside  to  "age"  or  allow  of  the  completion  of  the  chemical  change. 
Finally  the  solution  is  put  in  steel  cylinders  and  under  a  pressure  of  from 
forty  to  fifty  atmospheres  is  driven  through  fine  glass  tubes  with  minute 
apertures  into  water  acidulated  with  one-half  of  one  per  cent,  of  nitric  acid 
and  thence  wound  directly  upon  bobbin-.  The  skein-*  are  then  dr'ed  rapidly 
by  a  current  of  warm  air  at  45°  C.  and  denitrated  with  a  bath  or'  an  alka- 
line sulphide.  After  thorough  washing  and  drying  it  is  ready  for  t'-ea?  merit 
like  common  silk,  taking  the  basic  aniline  dyes  very  read;lv. 

Other  processes  for  the  manufacture  of  analogous  "  artificial  silk"  fibres 
from  cotton  use  ammoniacal  cupric  hydrate  solution  and  zinc  chloride. 
Cross  and  Bevan  have  also  prepared  a  similar  artificial  and  lustrous  fibre 
from  their  cellulose  xanthogenate  or  viscose  product. 


314  TEXTILE   FIBRES   OF   ANIMAL   ORIGIN. 


m.  Products. 

A.  WOOL. — We  have  already  alluded  to  the  distinction  between  worsted 
and  woollen  yarns.     Formerly  all  long-stapled  wools  were  combed, — that 
is,  the  fibres  were  brought  as  nearly  as  possible  parallel  to  one  another  and 
were  then  spun  into  what  was  known  as  worsted  yarn,  used  in  hosiery  and 
in  the  manufacture  of  fabrics  which  did  not  undergo  fulling.     All  short- 
stapled  wools,  on  the  other  hand,  were  carded  and  spun  much  as  cotton  is 
spun,  and  the  yarns  so  obtained  were  the  only  ones  capable  of  being  used 
in  making  milled  or  fulled  cloths,  in  which  the  felting  property  of  wool  is 
availed  of  to  thicken  the  cloth  after  weaving  and  in  which  by  teasels  the 
nap  of  the  cloth  is  raised  so  as  to  present  a  uniform  surface.     All  kinds  of 
wool,  therefore,  were  formerly  divided  into  combing  and  carding  or  cloth- 
ing wools.     Machines  have  been  invented  latterly,  however,  capable  of 
combing  wools  having  as  short  a  staple  as  one  inch,  and,  on  the  other  hand, 
wools  with  a  staple  as  much  as  five  inches  long  may  be  used  in  making 
milled  cloth.     So  the  distinction  between  the  several  wools  is  no  longer  as 
absolute  as  it  once  was. 

Among  the  chief  kinds  of  worsted  fabrics  are  serges  and  merinos  and 
mixed  goods  of  wool  and  mohair,  alpaca,  and  camePs  hair.  Hosiery  and 
carpets  also  belong  here,  although  the  best  of  these  latter  are  made  on  a 
ground  of  strong  linen  or  hemp.  The  principal  varieties  of  woollen  cloth 
are  broadcloths,  the  finest  variety  of  woollen  cloth,  cashmeres,  a  fine  thin 
twilled  fabric,  tweeds,  fabrics  of  looser  texture  than  broadcloth  and  less 
highly  milled,  doeskin,  a  strong  twilled  cloth,  blankets,  flannels,  etc. 

Shoddy  is  a  material  made  from  fragments  of  cast-off  woollen  clothing 
torn  into  fibres  and  re-spun  into  yarn.  It  is  looser  in  texture  than  mungo, 
which  is  made  from  remains  of  finer  fragments,  such  as  old  dress-coats, 
tailor's  clippings,  etc. 

A  third  grade  of  recovered  wool,  sometimes  called  extract  wool,  is  ob- 
tained from  union  goods  (mixed  woollen  and  cotton  goods)  by  the  process 
of  carbonizing  the  vegetable  fibre  and  then  beating  it  out.  The  carbonizing 
is  done  with  dilute  sulphuric  acid,  with  aluminum  chloride,  or  with  gaseous 
hydrochloric  acid.  The  last  process  is  said  to  give  the  best  results. 

B.  SILK. — The  raw-silk  threads  obtained  in  the  reeling  process  are  not 
sufficiently  strong  for  use  in  the  loom,  so  several  must  be  united.     This  may 
be  done  in  different  ways.     By  the  union  of  two  or  more  single  threads, 
separately  twisted   in  the   same   direction,  which  are   then   doubled   and 
retwisted  in  the  opposite  direction,  is  obtained  organzine.     The  best  grades 
of  silk  are  also  taken  for  the  organzine,  which  is  to  form  the  warp  in  silk- 
weaving.     The  product  of  the  union  of  two  or  more  simple  untwisted 
threads  which  are  then  doubled  and  singly  twisted  is  tram,  which  forms  the 
weft  in  weaving. 

Waste  silk  is  that  which  proceeds  from  perforated  and  double  cocoons 
and  such  as  are  soiled  in  steaming  or  in  any  other  way.  This  waste  silk  is 
washed,  boiled  with  soap,  and  dried.  When  carded  and  spun  like  cotton  it 
yields  the  so-called  flurt-silk. 

Satins  are  tissues  so  woven  that  almost  the  only  threads  appearing  on 
the  right  side  of  the  tissue  are  weft  threads,  which  present  a  uniform  glossy 
surface. 

Velvets  are  tissues  in  which  the  outer  surface  presents  to  view  a  short 
soft  pile,  made  by  passing  the  warp  threads  over  fine  wires,  which  are  after- 


ANALYTICAL   TESTS   AND   METHODS. 


315 


wards  drawn  out.  The  loops  then  remaining  are  either  left  as  they  are,  in 
which  case  the  tissue  is  called  pile-velvet,  or  cut  to  form  cut-velvet.  This 
fabric  is  now  largely  imitated  in  cotton  and  mixed  tissues. 

IV.  Analytical  Tests  and  Methods. 

1.  GENEKAL  DISTINCTIONS  BETWEEN  VEGETABLE  AND  ANIMAL 
FIBEES. — A  general  scheme  for  distinguishing  between  the  sevefal  "classes 
of  fibres  has  been  proposed  by  R.  Schlesinger  in  his  "  Leitfaden  fur  die 
mikroskopische  und  mikrochemische  Analyse  der  technisch  verwendeten 
Rohstoffe  der  Textil-Industrie."  It  is  in  outline  as  follows  : 


TREAT  WITH  CAUSTIC  SODA. 

The  fibre  does  not  dissolve  in 
ten  per  cent,  caustic  soda 
solution,  and  in  burning, 
which  takes  place  readily, 
does  not  develop  any  burnt- 
horn  odor. 

Vegetable  fibres. 

The  fibre  dissolves  in  concen- 
trated  caustic    soda,   and 
when  treated  with  ammo- 
niacal  cupric  oxide  shows 
scales  upon  its  surface. 

Animal  hairs  or  wool. 

The  fibre  does  not  dissolve  in 
cold  ten  per  cent,  caustic 
soda,   but    dissolves   per- 
fectly in  concentrated  sul- 
phuric acid  ;  shows  neither 
scales  nor  medullary  sub- 
stance. 

Silks. 

The  vegetable  fibres  are  then  to  be  studied  by  the  aid  of  the  iodine  and  dilute  sul- 
phuric acid  reaction,  and  the  several  groups  already  noted  in  the  classification  on  p.  263  are 
established. 

The  animal  hairs  are  to  be  distinguished  best  by  the  microscopical  characters  and 
measurements. 

The  several  varieties  of  silk  are  also  to  be  distinguished  by  a  comparison  of  the  diame- 
ters of  the  fibre  as  measured  under  the  microscope. 

A  scheme  for  distinguishing  between  the  more  important  textile  fibres, 
based  upon  their  behavior  to  the  two  dyes  malachite-green  and  Congo-red, 
and  after  examination  under  the  microscope,  has  been  proposed  by  Behrens 
("  Microchemische  Analyse,"  2te  Heft,  p.  51).  The  grouping  thus  estab- 
lished is  as  follows : 

Group  A.   Dyed  fast  to  washing  by  malachite-green. 
Here  belong,  of  the  textile  fibres,  silk,  wool,  and  jute. 

Aa.  Not  capable  of  supplementary  dyeing  by  aromatic  amines  :  silk  and  wool. 
Ab.   Capable  of  supplementary  dyeing  by  aromatic  amines  :  jute. 
Group  B.  Dyed  partially  fast  only  by  malachite-green. 
Hemp  and  manila. 

Ba.  Strongly  polarizing  :  hemp. 
Bb.  Weak  polarizing  :  manila. 
Group  C.   Fugitive  dyeing  with  malachite-green;  complete  supplementary  dyeing  with 

benzidine  dyes. 

Here  belong  cotton  and  flax. 
Ca.  Weak  polarizing  :  cotton. 
Cb.  Strongly  polarizing  :  flax. 

Several  of  the  simpler  differences  between  the  vegetable  and  the  animal 
fibres  as  groups  have  already  been  alluded  to  in  classifying  the  fibres.  (See 
p.  273.)  Other  special  tests  are  as  follows  : 

1.  Millon's  reagent  (mercurous  and  mercuric  nitrate)  colors  the  animal 
fibres  red,  but  not  the  vegetable  fibres. 

2.  Liebermann  gives  the  following  test :    Prepare  a  fuchsine  solution, 
add  potash  solution  drop  by  drop  until  it  is  decolorized,  filter,  and  dip  in 
the  sample  of  goods.     Wool  or  silk  fibres  are  colored  red,  cotton  remains 
colorless. 


316  TEXTILE   FIBEES   OF   ANIMAL   ORIGIN. 

3.  Ammoniacal  cupric  oxide  solution  dissolves  cotton  as  well  as  silk. 
While  cotton,  however,  is  precipitated  by  certain  salts  as  well  as  by  sugar 
and  gum,  silk  is  only  precipitable  by  acids. 

4.  As  wool  always  contains  sulphur,  a  sodium  plumbate  solution  (made 
by  boiling  red  lead  with  caustic  soda  solution  and  filtering)  is  at  once  black- 
ened on  contact  with  wool.     This  test  may  be  interfered  with  in  the  presence 
of  sulphur-treated  silk. 

5.  Wool  and  silk  may  be  distinguished  by  the  use  of  hot  hydrochloric 
acid.    Silk  dissolves  easily  in  this,  while  wool  merely  swells  up  but  does  not 
dissolve. 

6.  According  to  Hohnel,  wild  silks  behave  differently  from  true  silks 
with  chromic  acid.     If  a  cold  saturated  solution  of  chromic  acid  be  diluted 
with  an  equal  bulk  of  water  and  then  boiled  for  one  minute  with  the  sample  of 
silk,  the  true  silk  dissolves  up,  while  the  wild  silk  remains  unattacked  even 
after  two  to  three  minutes7  boiling.     Wool  behaves  like  true  silk  in  this. 

A.  Remont  gives  a  process  for  determining  wool,  silk,  and  cotton  when 
mixed  in  the  same  fabric.  Four  pieces  of  about  two  grammes'  weight  each 
are  taken  ;  three  of  these  are  boiled  for  a  quarter  of  an  hour  in  two  hun- 
dred cubic  centimetres  of  three  per  cent,  hydrochloric  acid,  which  is  renewed 
if  the  liquid  becomes  strongly  colored,  and  the  samples  are  then  well  washed. 
The  dressing  is  thus  removed  and  the  coloring  matter  in  the  case  of  the 
cotton,  but  only  slightly  in  the  case  of  wool  and  silk  ;  the  weighting  of  the 
silk  with  iron  salts  is  also  completely  removed  by  the  hydrochloric  acid  if 
the  weighting  does  not  exceed  twenty-five  per  cent,  of  the  weight  of  the 
silk,  leaving  the  fibres  chestnut-brown  in  color.  Two  of  the  samples  thus 
treated  are  dipped  for  one  to  two  minutes  into  a  boiling  solution  of  basic 
chloride  of  zinc  of  specific  gravity  1.69 ;  then  thrown  into  water  and 
washed  first  with  acidified  water  and  then  with  pure  water.  This  removes 
the  silk.  The  basic  chloride  of  zinc  solution  is  prepared  by  heating  one 
thousand  parts  of  zinc  chloride,  forty  parts  of  zinc  oxide,  and  eight  hun- 
dred and  fifty  parts  of  water. 

One  of  the  two  samples  freed  from  silk  is  then  boiled  gently  for  a  quarter 
of  an  hour  with  sixty  to  eighty  cubic  centimetres  of  caustic  soda  solution  of 
specific  gravity  1.02.  This  is  best  done  with  inverted  condenser,  so  that  an 
injurious  concentration  of  the  soda  solution  is  avoided.  Wash  gently  with- 
out  too  much  rubbing  and  the  wool  is  removed.  All  four  samples  are  now 
washed  for  a  quarter  of  an  hour  with  distilled  water,  pressed  out,  dried  in 
the  air,  and  weighed.  The  first  will  weigh  as  before,  two  grammes  or  nearly, 
a  slight  difference  of  a  few  milligrammes  being  neglected  ;  the  difference  in 
weight  between  the  first  and  second  samples  gives  the  dressing ;  that  between 
the  second  and  third  gives  the  silk ;  that  between  the  third  and  fourth  the 
wool  present,  and  the  weight  of  the  fourth  sample  the  vegetable  fibre  present. 
This  is  slightly  attacked  by  the  soda  solution,  and  in  the  case  of  cotton  it  is 
usual  to  reckon  five  per  cent,  as  the  loss  from  this  cause. 


V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1867. — Einleitung  in  die  technische  Microscopie,  J.  Wiesner. 

1869. — Darstellung  der  Baues  und  der  Eigenschaften  der  Merinowolle,  M.  Settegast,  Berlin. 

1873. — Die  Gespinnstfasern,  K.  Schlesinger,  Zurich. 

1874.— Die  Wollgarnfarberei,  Kichter  und  Braun,  Berlin. 


BIBLIOGRAPHY   AND   STATISTICS. 


317 


1878. — Le  Conditionnement  de  la  Sole,  J.  Persoz,  Paris. 

1880.— The  Woollen  Thread:  its  Nature,  Structure,  etc.,  C.  Vickerman,  Huddersfield. 

1881. — Die  Gewinnung  der  Gespinnstfasern,  H.  Richard,  Braunschweig. 

Matieres  premieres  organiques,  Pennetier,  Paris. 

The  Wild  Silks  of  India,  Th.  Wardle,  London 

1882. Chevallier's  Dictionnaire  des  Falsifications,  4me  ed.,  Baudrimont,  Paris. 

1885.— The  Dyeing  of  Textile  Fabrics,  J.  J.  Hummel,  London. 

The  Structure  of  the  Wool  Fibre,  F.  H.  Bowman,  Manchester. 

L'Art  de  la  Soie,  N.  Rondot,  Paris. 

Les  Soies,  N.  Rondot,  Paris 

1886. The  Catalogue  of  the  Silk-Culture  Court,  Indian  Exhibition,  Th.  Wardle,  London. 

1887. — Microscopic  der  Faserstofle,  F.  von  Hohnel,  Vienna. 

1888.— Chemische  Technologic  der  Gespinnstfasern,  Otto  Witt,  Braunschweig. 

Wool  Manufacture,  R.  Beaumont,  London. 
1890. — Les  Industries  de  la  Soie,  Sericulture,  etc.,  E.  Pariset,  Lyons. 

La  Soie,  L.  Vignon,  Paris 

Industrie  de  la  Soie,  F.  Dehaitre,  Paris. 

1895. — Grundriss    der   Allgemeinen    Waarenkunde,    Erdman-Konig,    12te    Auf,   Von 
Hanausek,  Leipzig. 


STATISTICS. 


Wool. — The  following  figures  show  the  production,   importation, 
home  consumption  of  wool  for  the  United  States  in  recent  years : 


and 


YEAR. 

Production. 

Imports. 

Total  production 
and  imports. 

Home  consump- 
tion. 

Percentage 
imported. 

Pounds. 

Pounds. 

Pounds. 

Pounds. 

1895  .    .    . 

309,748,000 

206,033,906 

515,781,906 

509,159,716 

40.0 

1896  .    .    . 

272,474,708 

230,911,473 

503,386,181 

490,413,964 

45.9 

1897  .    .    . 

259,153,251 

350,852,026 

610,005,277 

601,305,908 

57.8 

1898  .    .    . 

266,720,684 

132,795,202 

399,515,886 

396,889,915 

32.8 

1899  .    .    . 

272,191,330 

76,736,209 

348,927,539 

334,832,204 

19.2 

The  importations  of  wool  during  the  last  few  years  are  thus  classified  : 


Class  I.—  Clothing  wool  (Ibs.)  . 
Valued  at           

1896. 
.  117,233,440 

119,448,471 

1897. 
200,759,079 
$34,281,656 

1898. 
45,442,987 
$7,969,611 

1899. 
12,976,999 

$1,948,954 

Class  II.—  Combing  wool  (Ibs.) 
Valued  at           
Class  III.  —  Combing  wool  (Ibs.) 
Valued  at    . 

.    15,756,318 
.    $3,509,736 
.    97,921,715 
.    $9,493,035 

37,951,490 
$7,187,620 
112,141,457 
$11,773,915 

4,320,873 
$859,599 
83,031,342 

$7,954,482 

2,155,419 

$587,061 
61,603,791 

$5,786,882 

The  "  wool  book"  of  the  National  Association  of  Wool  Manufacturers 
gives  the  following  as  the  world's  production  for  1891 : 


Europe :  Pounds. 

Russia 291,500,000 

Great  Britain  and  Ireland    .  147,47'>,000 

France 124,803,000 

Spain 66,138,000 

Germany 54,894,000 

Hungary      43,146,000 

Austria 11,155,000 

Italy         21,385,000 

Portugal 10,362,000 

Belgium 4,409,0<iO 

Sweden     . 3,307,000 

All  other  Europe 8,818,000 

Total  Europe 787,392,000 


North  America: 
United  States .    . 
British  provinces 


Pounds. 

307,100,000 

12,000,000 


Total  North  America   .    319,100,000 


South  America : 

Argentine  Republic  . 

Brazil 

Peru          , 

Uruguay  


Total  South  America 
Australasia .    . 


376,700,000 

1,875,000 

6,700,000 

42,000,000 

427,275,000 
550,000,000 


318 


TEXTILE   FIBEES   OF   ANIMAL   ORIGIN. 


Asia:                                                    Pounds.  Africa:                                                Pounds. 

British  East  Indies    ....  72,000,000  Cape  Colony,    1                         -,  9ft  Aft1  fim 

Kussia 66,000,000  Natal,                f 1^8,681,60 

As^tic      Turkey,      Persia,  Egypt 2,800,000 

Thibet,  Afghanistan,  etc.  12,200,000 

Sivas,  Asiatic  Turkey  .    .    .        8,300,000  Total  Africa 131,481,600 

Mesopotamia 31,555,000 

Persia 3,470,000  A11  otner  countries 48,000,000 

Total  Asia 193,525,000  Total  production    .    .     2,456,773,600 

The  wool  clip  of  the  principal  fine  wool-producing  countries  for  1894 
is  given  as  follows  : 

United  States 325,000,000  pounds. 

Australasia 581,000,000       " 

Cape  of  Good  Hope 122,000,000       « 

KiverPlatte 443,000,000       « 

Total 1,471,000,000       " 

(Textile  Manufacturer,  June  15,  1895.) 

The  entire  wool  clip  for  1894  is  estimated  to  have  been  2,692,000,000 
pounds. 

The  following  statistics  of  the  Australian  wool  export  are  given  in  the 
United  States  Consular  Reports  of  June,  1890 : 

1888-89.  1889-90. 

Bales.  Bales. 

Victoria 336,702  400,459 

New  South  Wales 422,863  443,820 

Queensland 87,763  85,206 

South  Australia 118,656  143,215 

West  Australia 21,170  24,337 

Tasmania 19,536  19,251 

New  Zealand 207,023  210,265 


1,215,712 


1,326,643 


The  value  of  the  clip  in  1889-90  is  placed  at  £21,253,188,  or  $103,- 
428,639. 

The  number  of  sheep  in  the  United  States  in  1891  is  stated  by  the 
Department  of  Agriculture  to  have  been  43,430,000. 

The  number  of  sheep  in  the  Argentine  Republic  for  the  year  1887  is 
given  as  103,413,817. 

The  number  of  sheep  in  all  the  Australian  colonies  in  1891  is  reported 
to  have  been  114,628,301. 

The  "wool  book"  for  1892  gives  the  following  comparison  of  the 
quantities  of  wool  manufactured  in  the  United  States,  England,  France, 
and  Germany  at  the  dates  stated  : 


United  States  (imported  and 
home  grown) 

United  Kingdom  (imported 
and  home  grown) 

France 

Germany 


1866. 


Pounds. 
229,707,000 

313,000,000 

*190, 119,000 

no  returns. 


1876. 


Pounds. 
235,020,000 

369,000,000 
*271, 484,000 
*143,260,000 


1884. 


Pounds. 
376,036,000 

381,000,000 
*365, 767,000 
*232,962,000 


1890. 


Pounds. 
415,000,000 

470,000,000 
420,000,000 
340,000,000 


*  Home  grown  not  included. 


BIBLIOGRAPHY   AND   STATISTICS. 


319 


Silk. — The  statistics  for  the  production  of  raw  silk  for  the  year  1890 
throughout  the  world  are  thus  given  in  Dammer's  "  Handbuch  der  Chem- 
ischen  Technologic/'  Bd.  v.  p.  30 : 

Europe : 

Italy 3, 443, 000  kilos. 

France 650,000 

Austria-Hungary  ....  245,000 

Balkan  States 154,000 

Spain 84,000 

Switzerland 40,000 

Portugal,  etc 4,000 


Total 


.  4,620,000 


Asia : 

China 11,000, 000  kilos. 

Japan 6,000,000 

East  Indies 1,500,000 

Asiatic  Kussia 656,000 

Syria,  Asia  Minor    ...  571,000 

Persia      275,000 

Farther  India 270,000 

Miscellaneous 100,000 


Total 20,372,000 


The  exports  of  raw  silk  from  different  Asiatic  ports  during  the  last  two 
years  have  been  as  follows  : 


1898. 

Kilos. 

Persia  and  Turkestan 133,000 

China  (Shanghai  and  Canton) 6,945,000 

Japan  (Yokohama) 3,122,000 

India  (Calcutta) 275,000 

Total  exports  from  Asia 10,475,000 


1899. 
Kilos. 
240,000 
7,755,000 
3,430,000 
350,000 

11,775,000 


(Lyons  Silk  Merchants'  Union.) 

The  importations  of  raw  silk  into  the  United  States  for  the  last  five 
years  have  been  as  follows : 

1895 7,974,810  pounds,  valued  at  $22,029,068 

1896 8,000,621        "  "       "     26,246,902 

1897 6,513,612       "  "       "     18,496,944 

1898 10,315,162        "  "       "     31,446,800 

1899 9,631,145       "  "       " 


320 


ANIMAL   TISSUES   AND   THEIR   PRODUCTS. 


CHAPTER  X. 


ANIMAL   TISSUES   AND   THEIR   PRODUCTS. 

A.  LEATHER  INDUSTRY. 

I.  Raw  Materials. 

1.  ANIMAL  HIDES  AND  SKINS. — The  moist  animal  skin  undergoes 
decomposition  very  rapidly ;  if  dried  becomes  stiff  and  horny,  or  if  boiled 
with  water  is  changed  into  soluble  glue.  The  object  of  tanning  is  to  bring 
the  animal  skin  into  such  a  condition  that  decomposition  is  arrested,  and 
after  drying  it  no  longer  forms  a  stiff  horny  mass,  but  an  opaque  tissue  in- 
soluble in  water,  distinctly  fibrous  and  pliable.  The  product  known  as 
leather  has  properties  which  at  once  distinguish  it  from  the  untanned  hide, 
such  as  greater  or  less  impermeability  to  water  and  toughness  and  strength. 
Nevertheless,  the  best  authorities  on  the  subject  believe  that  in  the  main 
tanning  is  a  physical  rather  than  a  chemical  process,  and  that  the  function 
of  the  tanning  material  is  chiefly  to  penetrate  the  pores  of  the  skin  and 
envelop  the  individual  fibres  so  that  in  drying  they  are  prevented  from  ad- 
hering and  so  stiffening  the  whole  mass.  The  power  of  the  skins  to  fix 
tanning  materials  upon  the  surface  of  its  fibres  varies  considerably  accord- 
ing to  the  nature  of  the  material  used,  and  in  many  grades  of  leather  is 
undoubtedly  supplemented  by 

a  chemical  combination  of  the  ^IG.  96. 

coriin   of  the  skin  with   the 
tannin. 

To  understand  the  nature 
of  the  change  wrought  by 
tanning  in  the  animal  hide,  it  is 
necessary  first  to  refer  briefly  to 
its  anatomical  structure.  Fig. 
96  shows  a  section  of  ox-hide 
cut  parallel  with  the  hair,  mag- 
nified about  fifty  diameters. 
It  consists  essentially  of  three 
layers  :  the  epidermis,  which  is 
itself  made  up  of  two  layers, 
the  outer  horny  layer  or  cuticle 
A,  a  dead  layer  which  is  con- 
tinually wearing  off  and  being 
renewed,  and  the  inner  mucous 
layer  J5,  the  rete  Malpighi,  a 
watery  cellular  layer,  which 
rests  upon  the  true  skin  and  is 
continually  renewing  the  outer 

layer ;  the  derma  or  corium,  the  true  skin,  (7,  which  alone  is  the  leather- 
making  tissue;  and  the  fatty  under  tissue,  shown  in  the  illustration  at  D,  in 


h  ~""£ 


h  -— 


RAW   MATERIALS.  321 

which  the  perspiratory  and  sebaceous  glands  are  embedded.  Both  the  epi- 
dermis and  the  under  tissue  are  removed  in  the  preparatory  processes  of 
tanning,  so  that  the  corium  alone  remains  to  combine  with  the  tanning 
materials  to  form  leather.  The  hair  of  the  animal  is  enclosed  in  hair- 
sheaths,  which  pass  down  through  the  epidermis  and  rest  upon  the 
corium,  from  which  in  life  the  hair-glands  draw  their  nourishment.  The 
corium,  or  true  leather-forming  layer,  is  composed  of  bundles  of  inter- 
lacing fibres,  between  which  is  found  an  albuminoid  substance,  coriin, 
which  as  the  skin  dries  cements  the  fibres  together  and  stiffens  the  hide. 
This  is  insoluble  in  water  but  soluble  in  lime-water,  and  hence  removed 
in  large  part  by  the  process  of  liming  to  which  the  hides  are  sub- 
mitted. 

The  animal  skins  which  are  utilized  in  the  manufacture  of  leather  are, 
first,  those  of  the  ox,  cow,  buffalo,  horse,  etc.  These  are  known  as  hides,  or 
if  from  younger  animals  of  the  same  kind  as  kips.  Second,  those  of  the 
calf,  sheep,  goat,  deer,  etc.  These  are  known  as  skins.  For  special  pur- 
poses the  skins  of  crocodiles,  alligators,  porpoises,  and  seals  are  also  made 
into  leather. 

The  hides  may  come  to  the  tannery  according  to  the  source  whence  ob- 
tained either  as  fresh  or  green  hides, — that  is,  direct  from  the  slaughter- 
houses,— as  wet  salted,  as  dry  salted,  and  as  dried  hides.  In  addition  to  the 
domestic  production,  great  numbers  of  hides  are  imported  into  the  United 
States  from  the  Argentine  Republic  and  the  River  Plate  in  South  America. 
England  imports  from  India,  the  Cape  of  Good  Hope,  and  Australia  as 
well  as  from  South  America.  Goat-skins  for  the  morocco  trade  are  brought 
mainly  from  India  and  the  East. 

2.  TANNIN-CONTAINING  MATERIALS. — The  conversion  of  the  hides 
into  leather  is  usually  accomplished  by  the  action  of  an  extract  or  infusion 
of  tannin  or  tannic  acid.  This  powerful  astringent  acid  is  very  widely  dis- 
tributed in  nature,  being  found  in  barks,  roots,  leaves,  seed-pods,  flowers, 
and  fruits,  and  in  excrescences  on  trees.  More  accurately  speaking,  we 
find  a  number  of  varieties  of  tannic  acid  in  these  different  vegetable  sources, 
of  which  some  are  more  valuable  for  tanning  than  others.  As  a  class  they 
are  readily  soluble  in  water,  amorphous,  of  slight  acid  reaction,  and  astrin- 
gent taste.  They  yield  with  iron  salts  bluish-black  or  greenish  precipitates, 
throw  gelatine  and  albumen  out  of  solution,  and  change  hides  into  leather. 
In  tanning  it  is  not  necessary  to  extract  the  acid  in  a  pure  state,  but  in- 
fusions are  made  from  the  powdered  barks  as  needed,  or  concentrated  ex- 
tracts prepared  for  this  purpose  are  used.  We  will  note  briefly  the  more 
important  tannin-containing  materials  used  at  the  present  time  in  leather 
manufactures. 

Oak-bark. — The  common  English  oak  ( Quercus  Robur),  which  includes 
the  two  varieties  Q.  peduneulata  and  Q.  sessiliflora,  is  one  of  the  most  im- 
portant materials.  It  contains  from  twelve  to  fifteen  per  cent,  of  tannic 
acid  and  produces  an  excellent  quality  of  leather.  Other  varieties  in  use 
are  Quercus  coed/era  (or  kermes-oak),  of  which  the  bark,  known  as  coppice- 
oak,  is  yellowish-brown  in  hue  and  very  rich  in  tannin ;  Quercus  suber  (or 
cork-oak)  and  Quercus  Ilex  (or  evergreen-oak),  both  of  which  are  grown  in 
Algiers,  Italy,  Spain,  and  the  South  of  France.  In  the  United  States  the 
most  important  varieties  of  oak  are  Quercus  prinus  or  castanea  (chestnut- 
oak)  ;  Quercus  rubra  (common  red -oak);  Quercus  alba  (or  white-oak). 
The  tannin  of  the  several  varieties  of  oak  is  known  as  quercitannic  acid. 

21 


322  ANIMAL   TISSUES   AND   THEIR   PRODUCTS. 

According  to  the  researches  of  Etti,*  the  main  constituents  of  the  oak-bark 
are  querdtannic  add  with  the  formula  C17H16O9 ;  its  first  anhydride,  phlo- 
baphene,  C^H^O^;  its  second  anhydride,  C34H28O16;  its  third  anhydride, 
Oser's  oak-red,  C34H26O15 ;  and  its  fourth  anhydride,  Lowe's  oak-red,  C34H24O14. 
Of  these,  the  quercitannic  acid  and  the  phlobaphene  are  specially  concerned 
in  the  tanning  process. 

Hemlock-bark. — The  bark  of  the  hemlock  (Abies  Canadensis)  of  Canada 
and  the  United  States  contains  nearly  fourteen  per  cent,  of  tannin.  This  is 
extensively  used,  either  jointly  with  oak-bark  (union  tanned  leather)  or  as 
a  substitute  for  it,  in  the  manufacture  of  sole-leather.  It  is  said  to  produce 
a  harder  leather  than  oak-bark,  but  less  pliable  and  more  pervious  to  water. 
A  solid  extract  from  the  hemlock-bark  containing  from  twenty-five  to 
thirty-five  per  cent,  of  a  deep  red  tannin  is  prepared  in  large  quantities  for 
export.  The  production  of  this  solid  extract  is  said  to  be  at  present  con- 
siderably over  ten  thousand  tons  per  annum.  Liquid  extracts  with  fifty 
per  cent,  of  solid  matter  are  also  largely  sold. 

Pine-bark  is  much  used  in  Austria,  Bavaria,  and  Southern  Germany. 
It  contains  from  seven  to  ten  per  cent,  of  tannin  and  considerable  resinous 
extractive  matter.  It  does  not  yield  so  good  a  leather  as  oak-bark. 

Closely  related  and  somewhat  used  are  the  barks  of  the  White  Spruce, 
the  Larch,  and  the  Fir. 

Willow-bark. — Several  species  of  the  willow,  notably  Salix  arenaria  and 
S.  caprcea,  are  used  in  Russia  and  Denmark  for  the  tanning  of  lighter  skins, 
for  the  manufacture  of  glove  leather  and  the  so-called  Russia  leather.  It 
is  stated  that  the  yearly  consumption  of  willow-bark  in  Russia  at  present  is 
some  six  and  a  half  million  kilos,  against  two  and  a  half  million  kilos,  of 
all  other  tanning  barks.  The  percentage  of  tannin  in  the  willow  is  usually 
given  at  from  three  to  five  per  cent.,  although  Eitner  f  found  over  twelve 
per  cent,  in  several  species. 

Chestnut-wood. — The  wood  of  the  chestnut  ( Castanea  vesca)  contains  from 
eight  to  ten  per  cent,  of  a  tannin  which  closely  resembles  gallotannic  acid. 
The  extract,  containing  from  fourteen  to  twrenty  per  cent,  of  tannin,  is  used 
largely  to  modify  the  color  produced  by  hemlock  extract  and  for  tanning 
and  dyeing. 

Horsechestnut-bark. — The  bark  of  the  horsechestnut  (^Esculus  hippocas- 
tanum)  is  also  said  to  be  used  for  the  manufacture  of  an  extract  under  the  sim- 
ple name  of  "  chestnut  extract/'  but  such  manufacture  in  the  United  States 
is  very  doubtful. 

Catechu  (or  Catch)  is  the  name  given  the  dried  extract  from  Acacia  Cate- 
chu, cultivated  in  India  and  Burmah,  and  containing  forty-five  to  fifty-five 
per  cent,  of  a  special  variety  of  tannic  acid  (catechu  or  mimotannic).  The 
extract  is  evaporated  until  a  semi-solid  dark-brown  product  is  obtained.  This 
is  exported  in  mats,  bags,  and  boxes  to  European  and  American  markets. 

Gambier  or  Gambir  (Pale  Catechu)  is  the  dried  extract  from  the  leaves  of 
Uncaria  Gambier  and  U.  acida.  It  contains  thirty-six  to  forty  per  cent,  of  a 
brown  tannin  which  rapidly  penetrates  leather  and  tends  to  swell  it,  but  taken 
alone  produces  a  soft,  porous  tannage ;  it  is  largely  used  in  conjunction  with 
other  materials  for  tanning  both  light  and  heavy  leathers.  It  is  exported 
from  Singapore  in  pressed  blocks  and  cubes.  The  catechutannic  acid  of  cutch 

*  Wagner's  Chemical  Technology,  13th  ed.,  p.  1051. 
f  V.  Hohnel,  Die  Gerberinde,  p.  90. 


BAW   MATERIALS.  323 

and  gambier  differs  from  gallotannic  acid  in  giving  a  grayish-green  precip- 
itate with  ferric  salt  and  no  reaction  with  ferrous  salts ;  by  giving  a  dense 
precipitate  with  cupric  sulphate  and  none  with  tartar  emetic.  They  also 
contain  catechirij  which  is  said  to  be  an  anhydride  of  catechutannic  acid. 

Kino  is  an  extract  somewhat  resembling  cuteh,  and  is  the  dried  juice 
from  a  variety  of  plants.  Thus,  the  East  Indian  kino  is  obtained  from 
Pterocarpus  marsupium,  the  Bengal  kino  from  Butea  frondosa,  the  African 
from  Pterocarpus  erinaceum,  and  the  Australian  from  the  several  species  of 
Eucalyptus.  It  ordinarily  forms  small  angular  fragments  of  black  lustrous 
appearance,  brittle,  and  crumbling  to  brown-red  powder.  It  contains  thirty 
to  forty  per  cent,  of  a  tannin  (kinotannic  acid)  analogous  to  catechutannic 
acid,  together  with  phlobaphene. 

Sumach  consists  of  the  powdered  leaves,  peduncles,  and  young  branches 
of  Rhus  coriaria,  Rhus  cotinus,  and  other  species  of  Rhus.  Thus,  Sicilian 
sumach,  the  most  esteemed  variety,  is  from  R.  coriaria  ;  Spanish  sumach  is 
from  several  species  of  Rhus,  and  comes  in  three  varieties,  Malaga,  Molina, 
Valladolid  •  Tyrolean  sumach  from  R.  cotinus  ;  French  from  Coriaria  myr- 
tifolia;  American  from  R.  glabra,  R.  Canadense,  and  R.  copallina.  The 
leaves  are  collected  while  the  shrub  is  in  full  foliage  and  cured  by  dry- 
ing in  the  sun.  They  are  then  ground  under  millstones  and  the  product 
baled.  The  sumach  contains  from  sixteen  to  twenty-four  per  cent,  of  a 
tannin  which  seems  to  be  identical  with  gallotannic  acid.  The  American 
variety  contains  usually  six  to  eight  per  cent,  more  than  the  European,  but 
also  contains  more  of  a  dark  coloring  matter,  which  renders  it  inferior  to 
the  Sicilian  sumach  for  white  leathers. 

Myrobalans  (or  Myrabolans). — The  fruit  of  several  species  of  Termi- 
nalia  found  in  Hindostan,  Ceylon,  Burmah,  etc.  Myrobalans  varies  in  size 
from  that  of  a  small  hazel-nut  to  that  of  the  nutmeg.  The  tannin  occurs 
in  the  pulp  which  surrounds  the  kernel.  It  is  generally  used  in  combina- 
tion with  other  tanning  materials  to  modify  the  objectionable  color  which 
some  of  the  latter  impart  to  the  leather.  By  itself  it  produces  a  soft  and 
•porous  tannage. 

Valonia  is  the  commercial  name  for  the  acorn  cups  of  several  species 
of  oak,  Quercus  cegilops  and  Quercus  macrolepis,  coming  from  Asia  Minor, 
Roumelia,  and  Greece.  They  are  of  a  bright-drab  color,  and  contain 
twenty-five  to  thirty-five  per  cent,  of  a  tannin  somewhat  resembling  that 
of  oak-bark,  but  giving  a  browner  color  and  heavier  bloom.  It  is  generally 
used  in  admixture  with  oak-bark,  myrobalans,  or  mimosa-bark,  because  of 
itself  it  produces  too  brittle  a  leather. 

Mimosa-bark  (Wattle). — The  bark  of  numerous  species  of  Acacia  (A. 
decurrens  and  A.  dealbata)  from  Australia  and  Tasmania,  contains  from 
twenty-four  to  thirty  per  cent,  of  mimotannic  acid.  The  bark  comes  into 
commerce  chopped  or  ground  and  also  in  the  form  of  an  extract.  It  makes 
a  red  leather  and  is  generally  used  in  admixture. 

Dim-dim. — The  seed-pods  of  Ccesalpinia  Coriaria,  a  small  tree  found 
in  the  neighborhood  of  Maracaibo,  South  America.  The  pods  are,  about 
three  inches  long,  brownish  in  color,  and  generally  bent  by  drying  into  the 
shape  of  the  letter  S.  It  contains  thirty  to  fifty  per  cent,  of  a  peculiar 
tannin  somewhat  similar  to  that  of  valonia,  but  is  liable  to  fermentation. 

Quebracho. — This  is  the  name  applied  to  several  South  American  trees 
possessing  hard  wood.  They  are  Aspidosperma  Quebracho  (Quebracho 
bianco),  Loxopterygium  Lorentzii  (  Quebracho  Colorado).  The  wood  and  bark 


324  ANIMAL  TISSUES   AND   THEIR   PRODUCTS. 

of  the  latter  contain  from  fifteen  to  twenty-three  per  cent,  of  a  bright  red 
tannin.  Both  the  wood  and  the  extract  are  used  in  tanning. 

Nutgalls  is  the  term  applied  to  the  excrescences  on  plants  produced  by 
the  punctures  of  insects  for  the  purpose  of  depositing  their  eggs.  The 
principal  commercial  kinds  are  oak-galls  (or  Aleppo  galls)  and  Chinese 
galls.  The  first  of  these  are  the  product  of  the  female  of  an  insect  called 
Cynips,  which  pierces  the  buds  on  the  young  branches  of  the  Quercus  in- 
fectoria  and  other  species  of  oak.  In  the  centre  of  the  gall  thus  produced 
the  larva  is  hatched  and  undergoes  its  transformation,  boring  its  way  out  as 
a  winged  insect  in  five  to  six  months.  If  the  galls  are  gathered  while  the 
insect  is  in  the  larval  state  they  are  known  as  "  blue"  or  "  green"  galls ;  if 
the  insect  has  cut  its  way  out  they  are  known  as  "  white"  galls,  and  are  of 
inferior  character  and  less  astringent.  The  best  oak-galls  contain  from  sixty 
to  seventy  per  cent,  of  gallotannic  acid. 

The  Chinese  gallnuts  are  the  product  from  the  Rhus  semialata,  the  leaves 
of  which  are  punctured  by  an  insect,  the  Aphis  Chinensis.  The  nuts  are  of 
irregular  shape  but  are  very  rich  in  tannin,  containing  about  seventy  per  cent. 

Knoppern  are  galls  from  immature  acorns  of  several  species  of  oak 
largely  used  for  tanning  in  Austria.  They  contain  from  twenty-eight  to 
thirty-five  per  cent,  of  tannin. 

n.  Processes  of  Manufacture. 

Leather  may  be  manufactured  from  hides  or  skins  by  a  number  of 
methods,  which  may  be  summarized,  however,  under  three  heads, — viz., 
tanning  by  the  use  of  tannin-containing  barks  or  extracts ;  mineral  tanning, 
using  either  chromium  salts  to  make  an  insoluble  leather,  or  alum  and  salt, 
as  in  u  tawing ;"  and  the  manufacture  of  soft  leather  by  treatment  of  the 
skins  with  oils. 

We  will  note  first  the  methods  involving  the  use  of  tannin-containing 
materials,  and  these  again  differ  somewhat  according  to  the  grade  of  leather 
to  be  made  and  the  character  of  the  hides  or  skins  used. 

A.  MANUFACTURE  OF  SOLE-LEATHER. — 1.  Softening  and  Cleansing 
the  Hides. — This  process  differs  according  as  the  hides  are  taken  in  the  fresh 
or  green  state  or  are  salted  or  dried.  For  fresh  hides,  a  washing  with  pure 
water  to  cleanse  them  from  dirt  and  blood  is  all  that  is  necessary  to  pre- 
pare them  for  the  next  or  "  swelling"  process.  For  salted  hides,  a  soak- 
ing in  fresh  water  for  from  two  to  three  days  is  necessary,  while  for 
hard  dried  hides  a  longer  treatment  is  necessary,  first  in  water  which  has 
been  repeatedly  used  for  softening  and  afterwards  in  fresh  water.  This 
involves  often  a  slight  putrefaction  of  the  coagulated  albumen  of  the  dry 
hide.  To  control  this  and  prevent  injury  to  the  corium  of  the  hide  a  weak 
salt  solution  (five  per  cent.)  is  often  used  in  this  prolonged  softening. 
"  Stocking"  or  kneading  the  hides  with  heavy  rolls  or  breaking  weights  is 
also  needed  for  heavy  hides  which  have  been  dried. 

2.  Unhairing  and  Swelling. — These  operations  are  carried  out  together. 
As  the  swelling  proceeds  the  cells  in  which  the  roots  of  the  hair  are  embedded 
are  softened,  so  that  the  hair  is  easily  removed  by  mechanical  means.  The 
horny  epidermis  is  similarly  softened,  so  that  it  can  be  removed  by  the  same 
means.  The  swelling  may  be  effected  by  several  different  methods  :  (1)  by 
sweating ;  (2)  by  treatment  with  acid  tan-liquor  ;  (3)  by  liming  ;  (4)  by  treat- 
ment with  sulphides  of  sodium  and  ealcium,  etc.  The  sweating  process  now 


PROCESSES   OF   MANUFACTURE.  325 

in  use  is  the  so-called  "  cold  sweating"  method,  and  consists  in  hanging  the 
hides  in  a  moist  chamber  kept  at  a  uniform  temperature  of  60°  to  70°  F. 
(15°  to  21°  C.),  so  that  an  incipient  putrefaction  ensues  which  attacks  the 
soft  parts  of  the  epidermis  and  root-sheaths  before  materially  injuring  the 
corium  or  leather-forming  material.  This  method  is  that  generally  followed 
for  sole-leather  in  this  country  and  on  the  Continent  of  Europe,  while  in 
England  liming  is  more  generally  adopted.  The  swelling  with  acid  tan- 
liquor  depends  upon  the  action  of  the  acids  which  are  present  in  considerable 
quantity  in  old  tan-liquors  and  their  effect  upon  the  connective  tissue. 
The  swelling  and  unhairing  by  lime  always  adopted  for  small  skins  is  also 
used  for  sole-leather  hides  in  England.  A  view  of  the  lime-pits  and  skins 
in  process  of  softening  by  lime  as  carried  out  in  morocco  tanneries  is  shown 
in  Fig.  97.  The  action  of  the  lime  upon  the  hide  is  in  part  a  solvent  one. 
The  hair-sheaths  are  loosened  and  dissolved  and  the  hardened  epidermis 
swells  up  and  softens,  so  that  both  come  away  more  or  less  completely  with 
the  hair  when  scraped.  The  intercellular  substance,  or  coriin,  as  before 
stated,  is  also  soluble  in  the  lime-water,  and  as  this  is  removed  the  fibrous 
nature  of  the  leather-forming  skin  becomes  more  evident.  The  hides  are 
generally  put  into  several  lime-pits  in  succession,  in  the  first  of  which  is 
old  liquor  with  the  weakest  alkaline  reaction  because  of  its  partial  satura- 
tion with  organic  material,  and  in  the  last  the  liquor  is  the  freshest  and 
strongest  in  alkaline  reaction.  The  hides  require  to  be  turned  and  changed 
in  position  during  this  liming  process  as  well  as  removed  from  one  pit  to  the 
other.  The  swelling  and  unhairing  by  the  use  of  alkaline  sulphides  largely 
used  upon  the  Continent  of  Europe  consists  in  taking  a  solution  of  sodium 
sulphide  (made  from  alkali-waste  by  Schaffner  and  Helbig's  process)  and 
bringing  it  to  a  thin  pasty  condition  with  lime.  This  is  then  spread  upon 
the  hair  side  of  the  hides  and  they  are  packed  together  for  five  to  twenty 
hours,  when  the  loosened  hair  and  sulphide  paste  is  washed  off  and  the  hides 
left  in  water  a  time  longer  to  "  plump"  or  swell.  Another  process  uses  the 
sulphide  in  solution  only.  The  hair  having  been  loosened  by  one  or  the 
other  of  the  means  just  described,  it  is  to  be  removed  by  mechanical  means. 
This  is  usually  done  on  the  "  beam,"  a  sloping  frame  of  wood  or  metal  with 
a  blunt  two-handled  knife,  which  pushes  the  hair  downward  and  away  from 
the  workman.  After  the  unhairing,  the  loose  flesh  and  fat,  the  latter  some- 
what saponified  by  the  lime,  are  next  removed  from  the  inner  side  of  the 
hide  by  a  sharp-edged  knife.  Hand  "  fleshing"  is  in  many  cases  superseded 
by  machine  treatment,  as  the  hide  must  not  only  be  scraped  but  worked  to 
force  out  the  fat  which  remains  in  the  loose  tissue,  as  this  would  impede 
tanning.  The  hides  after  the  fleshing  are  trimmed,  and  the  inferior  ends 
and  edges  are  cut  off  with  a  sharp  knife.  They  have  still  to  be  freed  from 
the  traces  of  lime  which  they  have  absorbed  during  the  lime  treatment 
before  they  can  be  put  in  the  tan-liquors.  This  used  to  be  done  for  sole- 
leathers,  as  it  is  still  done  for  calf-  and  goat-skins,  by  means  of  "  bate,"  or 
dung  of  animals,  mixed  with  water,  but  that  is  now  almost  entirely  replaced 
by  the  use  of  dilute  acids  which  shall  combine  with  the  lime,  when  the  lime 
salts  so  formed  are  to  be  washed  out.  Dilute  sulphuric,  phosphoric,  and 
hydrochloric  acids  have  been  used  (the  latter  being  best  because  its  lime 
salt  is  soluble),  as  well  as  the  acid  tan-liquors  containing  gallic,  acetic,  and 
lactic  acids.  The  organic  acids  are  considered  to  be  safer  for  the  hide  than 
the  inorganic. 

3.   Tanning. — The  bark  or  other  tanning  material  must  be  crushed  and 


326 


ANIMAL   TISSUES   AND   THEIR   PRODUCTS. 


FIG.  97. 


PROCESSES   OF   MANUFACTURE.  327 

then  ground  to  a  state  sufficiently  fine  to  allow  of  the  extraction  of  the  tannic 
acid,  and  yet  not  so  fine  as  to  cause  it  to  cake  together  in  clayey  masses. 
This  is  accomplished  in  bark-mills  and  disintegrators  of  various  kinds, 
which  need  not  be  specially  described  here.  The  tan-house  into  which  the 
cleansed  and  prepared  hides  or  "  butts"  now  come  is  provided  with  rows  of 
pits  running  in  parallel  lines,  which  are  to  contain  the  butts  during  their 
treatment  with  the  tan-liquor.  The  butts  in  most  cases  are  firstrsuspended 
in  weak  tanning  infusions  before  they  go  into  the  first,  or  "  handler,"  pits. 
The  object  of  this  is  to  insure  the  uniform  absorption  of  tannin  by  the 
skins  before  subjecting  them  to  the  rough  usage  of  "  handling,"  which  in 
the  early  stages  of  the  process  is  liable  to  cause  injury  to  the  delicate  struct- 
ure of  the  skin.  During  this  suspension  the  skins  should  be  in  continuous 
agitation  to  cause  the  tannin  to  be  taken  up  evenly.  Both  the  suspension 
and  the  agitation  are  accomplished  generally  by  mechanical  means.  From 
the  suspenders  the  butts  are  transferred  to  the  "  handlers,"  where  they  are 
laid  flat  in  the  liquor.  They  are  here  treated  with  weak  infusion  of  bark, 
commencing  at  about  15°  to  20°  by  the  barkometer  (see  p.  335),  and  are 
handled  twice  a  day  during  the  first  two  or  three  days.  This  may  be  done 
by  taking  them  out,  turning  them  over,  and  returning  them  to  the  same 
pit,  or  more  generally  by  running  them,  fastened  together,  from  one  handler- 
pit  into  another.  The  treatment  of  the  butts  in  the  handlers  generally  occu- 
pies about  six  to  eight  weeks,  by  which  time  the  coloring  matter  of  the  bark 
and  the  tannin  should  have  "  struck"  through  about  one-third  of  the  sub- 
stance of  the  skin.  Many  of  the  butts  will  have  become  covered,  more- 
over, with  a  peculiar  "  bloom"  (ellagic  acid)  insoluble  in  water.  They  are 
now  removed  to  the  "  layers,"  in  which  they  receive  the  treatment  of  bark 
and  "  ooze,"  or  tan-liquor,  in  progressive  stages  until  the  tanning  is  complete. 
Here  the  butts  are  stratified  with  ground  oak-bark  or  valonia,  which  is 
spread  between  each  butt  to  the  depth  of  about  one  inch,  and  a  thicker 
layer  finally  on  top.  The  pit  is  then  filled  up  with  ooze,  which  varies  in 
strength  from  about  35°  barkometer  at  the  beginning  to  70°  at  the  end  of 
the  treatment.  For  heavy  tannages  six  to  eight  layers  are  required,  the 
duration  of  each  ranging  from  ten  days  at  the  beginning  to  a  month  in  the 
later  stages.  Each  time  the  butts  are  raised  they  should  be  mopped  on  the 
grain  to  remove  dirt  and  loose  bloom. 

With  the  use  of  strong  prepared  extracts,  especially  with  the  aid  of  heat, 
the  tanning  process  can  be  carried  out  in  much  shorter  time  than  that  just 
indicated,  but  the  leather  produced  though  hard  is  deficient  in  toughness 
and  is  liable  to  crack  on  bending  sharply. 

4.  Finishing. — The  butts  after  coming  from  the  last  layer  are  well 
brushed,  washed  in  a  clear  liquor,  and  then  thrown  over  a  horse  to  drain 
before  going  to  the  drying-shed.  They  are  then  frequently  oiled  lightly  on 
the  grain  so  as  to  prevent  too  rapid  drying  out  and  hung  on  poles  in  the 
drying-loft.  When  about  half  dry,  they  are  heaped  upon  the  floor  in  piles 
and  covered  to  sweat  a  little,  which  facilitates  the  operation  of  "  striking," 
which  next  follows. 

The  "  striking,"  which  may  be  done  by  hand  with  a  two-handled  tool 
with  triangular  blunt  edges  or  by  machinery,  is  chiefly  for  the  purpose  of 
removing  the  deposit  called  bloom,  although  it  somewhat  flattens  and 
stretches  the  leather.  After  a  little  further  drying  the  butt  is  laid  upon  a 
flat  bed  of  wood  or  metal  and  is  rolled  either  by  heavy  hand-rollers  or  by 
the  aid  of  machinery.  The  leather  is  then  sometimes  colored  on  the  grain 


328 


ANIMAL   TISSUES   AND   THEIR  PRODUCTS. 


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5 


PROCESSES   OF   MANUFACTURE.  329 

with  a  mixture  of  yellow  ochre,  with  size  and  oil  to  give  a  gloss,  and  then 
brushed  again,  well  rolled,  and  dried  off  gradually  in  a  room  slightly 
warmed  by  steam.  The  main  outlines  of  sole-leather  tanning  are  summa- 
rized on  the  accompanying  diagram. 

B.  UPPER  AND  HARNESS  LEATHERS. — For  upper  and  harness  leathers 
the  hides  of  cows  and  smaller  oxen  are  chosen.  Fresh  hides  are,  moreover, 
much  better  adapted  for  this  class  of  leathers  than  dry  salted  or  dry  "  flint" 
hides,  as  the  utmost  toughness  and  strength  rather  than  hardness  or  weight 
are  to  be  secured.  The  hides  are  cleansed,  limed,  and  unhaired  very  much 
as  already  described  for  sole-leather.  They  are  then  "  bated"  in  a  bate  of 
hen  manure  or  treated  with  sour  bran-liquor  to  completely  remove  the  lime 
from  the  pores  of  the  skin.  The  remaining  portions  of  hair-sheaths  and 
fat-glands  are  at  the  same  time  so  loosened  that  they  are  easily  worked  out 
by  a  blunt  knife  on  the  beam.  This  final  cleansing  process  is  called  "  scud- 
ding." The  action  of  the  "  bate"  is  considered  by  the  best  authorities  to 
be  a  fermentative  one,  and  the  weak  organic  acids  produced  neutralize  and 
remove  the  lime  and  at  the  same  time  soften  the  hide  by  dissolving  out  the 
coriin  and  probably  also  portions  of  the  gelatinous  fibre.  "  Stocking"  is 
also  used  to  assist  in  the  softening  and  cleansing.  These  lighter  tannages 
are  also  carried  out  very  largely  by  the  aid  of  gambier  in  combination  with 
bark,  valonia,  mimosa,  and  myrobalans.  The  tanning  liquors  are  often 
used  at  temperatures  of  from  110°  to  140°  F.  (43°  to  60°  C.).  The  finish- 
ing of  these  light  liquors  requires  much  care  in  order  to  give  them  the 
proper  softness  and  strength.  They  are  alternately  worked  with  a  stretch- 
ing-iron, or  "  sleeker,"  and  rubbed  with  oil  or  with  a  mixture  of  degras 
and  tallow. 

(7.  MOROCCO  LEATHER. — This  is  generally  made  from  goat-skins, 
although  a  cheaper  variety  is  made  from  sheep-skins.  The  skins  are  soft- 
ened and  then  unhaired  by  lime,  to  which  a  small  quantity  of  arsenic  sul- 
phide is  often  added,  whereby  calcium  sulphydrate  and  sulpharsenite  are 
produced,  which  assist  in  softening  the  hair-sheaths  and  in  giving  the  grain 
a  higher  gloss.  A  view  of  the  unhairing  machines  and  washing  drums  of  a 
morocco  tannery  is  given  in  Fig.  98.  They  are  then  bated  with  a  mixture 
of  dog's  dung  and  water,  known  as  the  "  pure."  This  is  often  followed 
by  a  treatment  with  bran  to  aid  in  removing  the  lime  from  the  skins.  A 
u  scudding"  or  scraping  with  a  blunt  two-handled  knife  on  both  the  grain 
and  flesh  sides  then  ensues  to  remove  the  last  portions  of  lime  salts  and 
albuminoid  matters.  The  tanning  was  formerly  done  with  sumadi  and 
gambier,  either  in  revolving  paddle  "  tumblers,"  as  shown  in  Fig.  99,  or 
according  to  the  English  method,  by  sewing  up  the  skins  into  bags  partially 
filled  with  the  sumach-liquor  and  then  distended  by  air  and  floated  in  a 
large  vessel  of  the  same  liquor.  The  bags  are  turned  over  constantly,  and 
afterwards  piled  up  in  heaps.  The  sumach  solution  is  thus  forced  through 
the  pores  of  the  skin,  and  the  tanning  is  rapidly  effected.  The  tanned 
skins  are  thoroughly  washed  and  "  struck,"  or  scraped  and  rubbed,  until 
smooth.  After  thorough  drying  they  are  again  struck  until  thoroughly 
soft  and  smooth.  This  sumach  tannage  has  been  replaced  in  this  country 
almost  entirely  by  the  chrome  tanning,  to  be  mentioned  later. 

D.  MINERAL  TANNING  OR  "  TAWING." — Skins  may  be  converted  into 
a  substance  resembling  leather,  although  in  fact  essentially  different  from  it, 
by  the  action  of  alum  and  salt.  There  has  been  no  chemical  combination, 
however,  analogous  to  that  formed  by  the  gelatine  and  tannic  acid  in  the 


330  ANIMAL   TISSUES   AND   THEIR   PRODUCTS. 

FIG.  98. 


PROCESSES   OF   MANUFACTURE. 


331 


ordinary  tanning  processes,  as  the  gelatine,  alum,  and  salt  can  be  again 
separated  by  treatment  with  water. 

The  process  of  tawing  is  applied  to  goat,  kid,  sheep,  and  other  small 
skins.  The  preliminary  operations  of  steeping,  breaking,  liming,  unhairing, 
and  fleshing,  steeping  in  bran-water  and  working  on  the  beam,  are  essen- 
tially the  same  as  have  been  described  already.  The  skins  with  the  pores 
cleared  of  lime  and  sufficiently  opened  are  then  put  into  a  kind  of~wooden 
drum  or  "tumbler"  such  as  are  used  for  washing  skins  and  for  treating 
morocco  leather  skins  with  sumach  solution.  For  every  two  hundred  skins 
some  twelve  pounds  of  alum  and  two  and  a  half  pounds  of  salt  with  twelve 
gallons  of  water  are  used. 

PIG.  99. 


The  action  is  continued  for  a  short  time  only, — about  five  minuter. 
They  are  then  put  into  an  emulsion  of  yolk  of  eggs  with  flour  and  water, 
and  tramped  and  worked  in  this  until  it  has  been  thoroughly  absorbed. 
The  skins  are  now  hung  upon  poles  to  dry,  after  which  they  are  stretched 
and  softened  by  drawing  them  to  and  fro  upon  the  "  stake,"  a  blunt  steel 
blade  set  in  upright  position. 

"  Combination  tanning,"  in  which  the  joint  action  of  gambier  and  alum 
is  used,  is  also  extensively  followed. 

Very  different  from  this  kind  of  mineral  tanning  is  that  introduced 
within  the  last  few  years  under  the  name  of  "chrome  tanning."  It  de- 
pends upon  the  power  of  chromium  oxide  (sesquioxide  of  chromium)  of 
forming  an  insoluble  compound  with  the  gelatigenous  fibre  of  the  hide, 
furnishing  a  product  which  possesses  in  a  high  degree  the  water-proof 
character  desirable  for  leather. 

The  process  generally  in  use  at  present  in  this  country  involves  treating 
the  skins  at  first  with  a  weak  solution  of  bichromate  of  potash  to  which 
sufficient  hydrochloric  acid  is  added  to  liberate  the  chromic  acid  (of  course 
pickled  skins  may  be  used  without  the  necessity  of  adding  free  acid). 
After  the  skins  have  taken  up  a  bright  yellow  color  through  their  entire 
texture  they  are  drained  and  transferred  to  a  bath  of  hyposulphite  of  soda 
to  which  some  acid  is  added  to  liberate  sulphurous  acid,  which  reduces  the 


332  ANIMAL  TISSUES   AND   THEIR   PRODUCTS. 

chromic  acid  to  green  chromic  oxide.  The  sulphurous  acid  is  at  the  same 
time  oxidized  to  sulphuric  acid,  which  liberates  a  further  portion  of  sul- 
phurous acid,  until  the  whole  of  the  chromic  acid  is  reduced.  Hydrogen 
sulphide  liberated  from  alkaline  sulphides  has  also  been  used  as  the  re- 
ducing agent  for  bichromated  skins,  and  still  more  recently  electrolytic 
hydrogen  developed  upon  the  bichromated  skin  itself.  In  any  case  the 
reduction  must  take  place  rapidly,  so  that  the  potassium  bichromate  may 
be  reduced  superficially  before  it  can  "  bleed"  or  diffuse  out  of  the  skins 
into  the  water  of  the  reducing  bath. 

The  leather  so  produced  is  of  a  pale  bluish-green  color,  tough  and 
flexible,  and  thoroughly  resistant  to  water.  Indeed,  it  is  this  latter  prop- 
erty which  distinguishes  it  from  all  other  forms  of  leather,  as  the  combi- 
nation of  the  hide  fibre  or  coriin  with  the  chromium  oxide  is  apparently 
more  stable  than  its  combination  with  tannin  and  yields  less  to  boiling 
water,  as  has  been  shown  in  tests  made  by  Professor  Henry  Procter,  of 
Leeds.  The  leather  can  also  be  dyed  and  produced  in  a  variety  of  colors, 
but  the  dyeing  must  be  done  before  the  leather  dries,  as  its  water-repellent 
character  is  such  that  once  dried  it  cannot  be  wetted  sufficiently  to  take 
up  a  full  color. 

Chrome-tanning  processes  involving  the  use  of  chrome  alum  and  other 
salts  of  the  sesquioxide  of  chromium  as  the  basis  of  the  tanning  vat  have 
been  used,  but  apparently  the  combination  does  not  take  place  so  readily 
as  where  the  chromium  oxide  is  obtained  in  statu  nascendi  by  reduction 
from  the  bichromate  under  the  influence  of  reducing  agents.  Basic  chro- 
mium salts,  such  as  the  basic  chromium  chloride,  have  also  been  proposed 
as  mineral  tanning  agents,  it  being  claimed  that  the  dissolved  chromium 
oxide  is  taken  up  by  the  hide-fibre  at  once  and  that  a  single  bath  only  is 
necessary  in  this  case.  Such  a  basic  salt  is  prepared  by  dissolving  com- 
mercial chromium  hydrate  (chrome  green)  in  hydrochloric  acid,  adding 
sal  soda  until  precipitation  of  the  hydrate  begins  again.  The  solution  is 
then  nearly  neutral,  and  contains  an  oxychloride  or  basic  chloride  in  solu- 
tion. Common  salt  is  also  added  to  prevent  injury  to  the  grain  of  the 
leather  and  to  facilitate  tanning.  After  the  absorption  of  the  chromium 
oxide  is  completed  the  skins  are  agitated  in  water  containing  suspended 
carbonate  of  lime  to  neutralize  all  traces  of  acid.  They  are  then  washed 
and  are  ready  for  the  fat  liquor.  At  the  present  time  the  bulk  of  the 
glazed  kid  made  in  the  United  States  is  chrome-tanned,  two  establishments 
in  Philadelphia  each  turning  out  at  present  three  thousand  dozen  chrome- 
tanned  goat-skins  daily. 

Quite  recently  formaldehyde,  applied  either  as  gas  or  in  aqueous  solu- 
tion, has  been  introduced  as  a  tanning  agent,  the  well-known  coagulating 
power  of  the  formaldehyde  on  animal  tissue  causing  it  to  unite  with  the 
hide  fibre  to  form  an  insoluble  leather.  All  grades  of  leather,  from  sole 
leather  to  light  morocco,  it  is  asserted,  can  be  made  readily  and  very  rapidly 
by  this  treatment.  As  yet,  it  is  too  early  to  judge  conclusively  of  its 
quality  and  durability. 

K  CHAMOIS  AND  OIL-TANNED  LEATHER. — The  skins  tanned  in  this 
way  are  sheep-  and  calf-skins,  and  formerly  chamois-  and  deer-skins.  The 
flesh  splints  of  sheep-skins  are  now  generally  employed  for  ordinary  wash- 
leather.  If  heavy  hides  are  taken,  the  grain  side  of  the  skin  is  shaved  so 
that  the  oil  can  penetrate  easily.  The  skins  receive  a  thorough  liming,  so 
that  the  coriin  is  thoroughly  removed  from  between  the  fibres,  making  them 


PRODUCTS.  333 

very  soft.  A  bran-drench  follows  to  remove  the  lime,  and  they  are  worked 
on  the  beam.  The  surplus  water  having  been  removed  by  pressing,  while 
still  moist  they  are  oiled  with  fish,  seal,  or  whale  oil  (to  which  some  five 
per  cent,  of  carbolic  acid  is  often  added).  After  being  stocked  for  two  to 
three  hours,  shaken  out,  and  hung  up  for  one-half  of  an  hour  to  an  hour  to 
partially  dry,  they  are  again  oiled  and  stocked,  and  this  process  is  repeated 
until  the  skins  lose  their  original  smell  of  limed  hide  and  acquirer  peculiar 
mustard-like  odor.  The  later  dryings  are  frequently  conducted  in  a  heated 
room,  and  when  the  oiling  is  complete  the  skins  are  piled  up,  and  the  oxida- 
tion of  the  oil  which  has  already  commenced  during  the  fulling  and  drying  is 
completed  by  a  sort  of  a  fermentation,  in  which  the  skins  heat  considerably. 
This  heating  must  be  controlled  so  that  the  leather  is  not  injured,  and  if 
necessary  the  pile  of  skins  is  turned.  When  the  oxidation  is  complete  the 
skins  are  of  the  yellow  chamois  leather  color.  To  remove  the  surplus  oil, 
the  skins  are  again  oiled,  then  thrown  into  hot  water  and  wrung  out. 
The  semi-solid  fat  obtained  this  way  is  the  d£gras  so  much  prized  for  curry- 
ing purposes.  Or  the  whole  of  the  uncombined  oil  is  removed  by  washing 
with  soda  or  potash  lye  and  then  set  free  by  neutralizing  with  sulphuric 
acid.  The  oil  so  obtained  forms  the  "  sod  oil"  of  commerce.  About  half 
of  the  oil  employed  is  retained  by  the  skin,  and  cannot  be  removed  even 
by  boiling  with  alkalies.  No  gelatine  is  obtained  by  boiling  with  water,  to 
which  the  chamoised  skin  is  much  more  resistant  than  ordinary  leather. 
The  skins  intended  for  gloves,  etc.,  are  bleached  like  linen,  by  sprinkling 
and  exposure  to  the  sun  or  with  weak  solution  of  potassium  permanganate 
followed  by  sulphurous  acid. 

HE.  Products. 

1.  SOLE-LEATHER. — This  is  the  heaviest  and  firmest  variety  of  leather 
produced.     It  is  made  from  the  heaviest  and  thickest  hides,  and  is  valued 
for  its  fine  grain  and  toughness.     It  retains  the  whole  thickness  of  the  hide, 
and  no  part  is  split  off,  so  that  it  is  not  weakened  by  the  loss  of  the  flesh 
side.     The  tanning  process  is  protracted  until  the  whole  hide  is  of  uniform 
color  throughout  and  shows  the  completed  action  of  the  tannin  upon  the 
interior  of  the  hide. 

2.  UPPER  AND  HARNESS  LEATHERS. — These  are  made  from  lighter 
hides,  and  are  tanned  for  strength  and  flexibility  rather  than  for  weight, 
and  are  finished  with  care  to  give  it  perfect  pliability.     It  may  be  shaved 
or  split  leather.     The  black  color  and  finish  are  put  on  upper  leather  by 
coating  it  with  a  mixture  of  lamp-black,  linseed  oil,  and  fish  oil,  to  which 
tallow  and  wax  and  a  little  soap  have  been  added.     This  is  brushed  on, 
allowed  to  dry,  and  then  thoroughly  rubbed  in  and  the  skin  sized  with  a 
glue  size. 

3.  MOROCCO  LEATHER. — The  true  morocco  leathers  are  manufactured 
from  goat-skins.     A  cheaper  grade,  known  as  French  morocco,  is  produced 
from  sheep-skins.     As  they  are  to  be  dyed  on  one  side  only,  two  of  the 
skins  are  fixed  face  to  face  with  the  flesh  side  inward,  so  that  the  dye  acts 
upon  one  side  of  each  skin  only.     After  dyeing  the  skins  are  rinsed  and 
drained,  saturated  with  linseed  oil  to  prevent  too  rapid  drying,  and  then 
curried  by  repeated  oiling  or  waxing  and  rubbing  with  a  glass  "  slicker." 

4.  ENAMELLED  OR  PATENT  LEATHERS. — These  are  leathers  finished 
with  a  water-proof  and  bright  varnished  surface  similar  to  lacquered  wood- 


334  ANIMAL   TISSUES   AND   THEIR   TKODUCTS. 

work.  The  name  "enamelled"  is  generally  applied  when  the  leathers  are 
finished  with  a  roughened  or  grained  surface,  and  "  patent/7  or  "  japanned," 
when  the  finish  is  smooth.  Thin  and  split  hide  are  used.  The  skins  after 
drying  are  prepared  with  a  mixture  of  linseed  oil  and  white  lead  and  heated 
in  closets  to  160°  F.  (71°  C.)  or  higher,  then  coated  with  a  varnish  of  spirits 
of  turpentine,  linseed  oil,  thick  copal  varnish,  and  asphaltum,  and  heated 
again  in  closets  or  "stoves,"  as  they  are  termed.  This  varnishing  and 
heating  are  alternated,  while  the  surface  is  meanwhile  rubbed  smooth  with 
pumice,  until  the  desired  thickness  is  acquired. 

5.  RUSSIA  LEATHER. — This  variety  is  peculiar  in  its  characteristic  odor 
and  ability  to  withstand  dampness  without  any  tendency  to  mould,  both  of 
which  qualities  it  owes  to  the  currying  with  the  empyreumatic  oil  of  birch- 
bark.     In  Russia  the  skins  are  tanned  with  willow-bark,  but  the  imitation 
Russia  leather  made  largely  in  Germany  and  England  is  tanned  in  the  ordi- 
nary way  with  oak-bark.     The  birch-bark  oil  is  rubbed  into  the  flesh  side 
of  the  tanned  skins  with  cloths,  care  being  taken  not  to  apply  so  much  as  to 
cause  it  to  pass  through  and  stain  the  grain  side  of  the  leather.     The  red 
color  is  given  by  dyeing  with  Brazil-wood  or  red  saunders,  and  the  diamond- 
shaped  marking  by  rolling  with  grooved  rollers. 

6.  CHAMOIS  LEATHER  is  a  soft  felt-like  leather  originally  prepared  from 
the  skin  of  the  chamois  goat,  but  now  made  from  other  goat-skins  and  from 
the  "  flesh-splits"  of  sheep-skins.     In  these  leathers  the  grain  has  practically 
been  removed  by  scraping  or  "  prizing"  before  the  oil  is  applied,  so  that  it 
is  uniformly  porous  and  soft  throughout.     They  acquire  a  yellow  color  and 
a  peculiar  odor,  although  they  are  often  bleached  whiter  by  subsequent  treats 
ment.     (See  preceding  page.)     The  combination  of  oil  with  the  hide  makes 
chamois  leather  very  resistant  to  water  and  allows  it  to  be  washed  without  any 
change  of  nature. 

7.  WHITE-TANNED  OR  "  TAWED"  LEATHER. — Skins  to  be  tanned  with 
the  hair  on,  as  sheep-skin  rugs,  etc.,  are  always  alum-tawed,  as  well  as  light 
calf  kid  and  glove  leather.     The  glove  leather  obtained  in  this  process  has 
softness  and  considerable  strength  but  is  not  thoroughly  water-resistant, 
although  the  treatment  with   egg-yolk  and  flour-paste  which  follows  the 
alum  treatment  tends  to  give  them  somewhat  of  this  character. 

8.  CROWN  LEATHER. — This  is  a  variety  which  is  intermediate  between 
oil-tanned  and  tawed  leather,  being  stronger  than  the  first  and  more  water- 
resistant  than  the  latter.     The  hides  are  first  tawed  with  the  alum  and  salt 
mixture,  then  washed  to  partially  dissolve  out  the  tawing  materials,  and 
now  spread  upon  a  table  and  the  flesh  side  covered  with  a  mixture  of  fat, 
ox-brain,  barley-flour,  and  milk.     They  are  then  put  into  a  revolving  tum- 
bler and  rotated  for  a  time,  and  again  rubbed  with  the  fat  mixture  and  ro- 
tated if  necessary.     The  leather  readily  becomes  mouldy,  but  seems  to  be 
strong  and  specially  adapted  for  belting. 

9.  PARCHMENT  AND  VELLUM. — The  first  of  these  is  prepared  from  the 
skins  of  sheep  and  goats  and  the  second  from  the  skins  of  calves.     The  skins 
are  washed,  limed,  unhaired,  and   fleshed,  again  well  washed,   and  then 
stretched  either  upon  hoops  or  upon  a  square  wooden  frame  called  the  herse. 
On  these  the  skin  while  wet  and  soft  is  stretched  thoroughly.     It  is  then 
scraped  again  free  from  the  fleshy  matters,  the  flesh  side  dusted  over  with 
sifted  chalk  or  slaked  lime  and  rubbed  in  all  directions  with  a  flat  piece  of 
pumice-stone.     The  grain  side  is  also  scraped  with  a  blunt  tool  and  rubbed 
with  pumice.     The  skin  is  then  allowed  to  dry  on  the  frame  in  the  shade, 


ANALYTICAL   TESTS   AND    METHODS.  335 

care  being  taken  to  avoid  sunshine  or  frost.  Very  fine  vellums  are  prepared 
with  the  finest  pumice-stone. 

10.  DEGRAS. — Among  the  side-products  of  the  leather  industry  is  one 
which  is  quite  valuable  for  after-use.  D6gras,  originally  obtained  only  as 
a  side-product  of  the  chamois-leather  manufacture,  is  now  also  made  spe- 
cially on  a  large  scale.  The  purest  d6gras  is  essentially  an  emulsion  of 
oxidized  fish  oil  produced  by  soluble  albuminoids.  That  which-  is-squeezed 
out  of  the  skins  after  the  completion  of  the  fermentation  and  heating,  which 
makes  the  last  stage  of  the  chamois-leather  manufacture  (see  preceding  page), 
is  the  finest  grade  of  degras.  That  which  is  recovered  by  the  aid  of  caustic 
alkalies  and  after-liberation  with  sulphuric  acid  is  the  second  grade  (sod  oil). 
The  great  demand  for  degras  for  currying  purposes  has  led  to  the  manufac- 
ture of  it  as  a  special  industry.  The  skins  used  for  this  purpose  are  treated 
exactly  as  in  the  normal  chamois-leather  manufacture,  but  are  used  over  and 
over  until  no  longer  capable  of  taking  up  the  oil.  An  artificial  degras  has 
also  been  made  from  oleic  acid,  fat,  and  a  little  lime  soap  to  which  some 
tannic  acid  had  been  added. 

Degras  is  of  semi-solid  consistence  and  has  a  peculiar  odor.  Its  specific 
gravity  is  higher  than  that  of  fish  oil,  and  after  dehydrating  is  from 
0.945  to  0.955.  Its  characteristic  constituent  is  the  so-called  degras-former, 
which  in  a  genuine  degras  should  range  from  twelve  to  twenty  per  cent. 
It  is  this  which  effects  the  ready  emulsion  with  water.  The  degras-former 
is  a  brown  resinous  saponifiable  substance,  fusing  at  from  65°  C.  to  67°  C., 
and  is  distinguished  from  fats  in  that  it  is  not  precipitated  when  in  alka- 
line solution  by  salt  and  is  not  soluble  in  petroleum-ether.  According  to 
Fahrion,  the  degras-former  is  a  mixture  of  oxy-fatty  acids. 

IV.  Analytical  Tests  and  Methods. 

1.  QUALITATIVE  TESTS  FOB  THE  SEVERAL  TANNING  MATERIALS. — 
H.  R.  Procter  *  has  constructed  the  following  table  (see  p.  337)  showing 
the  reactions  of  the  several  tanning  materials; 

2.  DETERMINATION  OF  STRENGTH  OF  TANNING  INFUSIONS. — This  is 
most  rapidly  and  conveniently  done  in  practice  by  the  use  of  the  specific 
gravity  hydrometer.     A  special  form  of  hydrometer  constructed  for  tan- 
ner's use  is  known  as  a  "  barkometer."     The  zero  point  of  the  scale  is 
taken  by  sinking  the  instrument  in  distilled  water  at  60°  F.,  and  the  10°, 
20°,  30°,  etc.,  marks  gotten  by  plunging  the  instrument  in  ten,  twenty,  and 
thirty  per  cent,  infusions  of  bark  respectively.     The  intermediate  degrees  are 
then  obtained  by  subdivision  of  the  spaces  as  taken  above.     It  is  of  course 
affected  by  the  presence  of  other  substances  than  tannin  in  the  solution, 
and  hence  its  indications  are  only  comparable  when  taken  on  fresh  or  par- 
tially-used liquors,  and  not  on  old  or  spent  liquors  loaded  with  impurities. 

3.  QUANTITATIVE  ESTIMATION  OF  TANNIN. — Of  the  numerous  pro- 
cesses that  have  been  described  for  this  purpose,  the  only  one  generally 
accepted  as  capable  of  sufficient  accuracy  is  LowenthaPs  permanganate 
method.     This  depends  upon  the  oxidation  of  the  tannin,  etc.,  by  permanga- 
nate of  potash  in  acid  solution  in  the  presence  of  indigo,  which  serves  as  in- 
dicator, as  its  oxidation  shows  the  end  of  the  reaction.     As  solutions  of  com- 
mercial tanning  materials  contain  other  oxidizable  matters  besides  tannins, 

*  Text-book  of  Tanning,  pp.  112  and  113. 


336  ANIMAL   TISSUES   AND    THEIR   PRODUCTS. 

it  is  necessary  to  separate  these  and  titrate  a  second  time  in  order  to  ascer- 
tain the  volume  of  permanganate  actually  required  by  the  tannin  present. 
This  separation  may  be  effected  by  digestion  with  hide-raspings,  or  more 
conveniently  by  a  solution  of  gelatine.  In  practice,  a  mixed  solution  of 
gelatine  and  common  salt  is  used  to  which  a  small  quantity  of  sulphuric  or 
hydrochloric  acid  is  added.  Procter  has  also  improved  the  process  by 
adding  kaolin,  after  the  gelatine  and  salt  have  removed  the  tannin,  for  the 
purpose  of  facilitating  filtration. 

The  special  precautions  and  details  of  the  process  as  generally  practised 
and  as  modified  by  the  Commission  of  German  Technical  Chemists  are 
given  in  Allen.*  The  results  are  always  stated  in  terms  of  crystallized 
oxalic  acid  to  which  the  tannin  is  equivalent  in  reducing  power  upon  the 
permanganate  solution,  and  are  gotten  by  the  aid  of  the  proportion 
c:(a  —  b) :  :  63  :x,  in  which  c  represents  the  volume  of  permanganate  needed 
for  ten  cubic  centimetres  of  decinormal  oxalic  acid,  a  and  6  the  volume  of 
permanganate  needed  for  the  tanning  infusion  before  and  after  precipitation 
of  the  tannin.  Another  method  of  a  different  kind  is  that  of  Simand  and 
Weiss,  as  used  in  the  Austrian  Experimental  Station  for  Leather  Industry, 
which  depends  upon  the  absorption  of  tannin  by  hide-powder.  An  extract 
of  the  tannin-containing  material  of  definite  strength  having  been  prepared,  f 
an  aliquot  portion  of  the  clear  filtered  solution  is  evaporated  to  dryness  in 
a  platinum  dish  until  constant  weight  is  obtained,  ignited,  and  the  weight 
of  ash  obtained  and  deducted.  A  second  definite  portion  (some  two  hun- 
dred cubic  centimetres)  of  the  same  solution  is  digested  with  hide-powder, 
using  the  rapid  filtration  apparatus  devised  by  Procter,!  and  from  the  fil- 
trate an  aliquot  portion  evaporated  as  before,  and  the  ash  determined  and 
deducted.  The  difference  between  the  first  and  second  weights  of  ash-free 
extract  gives  the  tannin  of  the  material  used. 

4.  DETERMINATION  OF  ACIDITY  OF  TAN-LIQUORS. — A  method  for 
the  determination  of  volatile  and  non-volatile  organic  acids  and  the  sul- 
phuric acid  present  in  acid  tan-liquors  has  been  given  by  Kohnstein  and 
Simand.§  One  hundred  cubic  centimetres  of  the  tanning  liquor  is  taken 
and  eighty  cubic  centimetres  distilled  off,  the  residue  diluted  and  again  dis- 
tilled with  steam.  The  acidity  of  the  distillate  is  determined,  and  the  result 
is  the  volatile  organic  acids  reckoned  in  terms  of  acetic  acid.  To  determine 
the  non-volatile  organic  acids,  eighty  cubic  centimetres  of  the  tanning  in- 
fusion is  treated  with  three  to  four  grammes  of  freshly-ignited  magnesium 
oxide  and  the  mixture  left  for  some  hours  with  frequent  agitation,  when  the 
filtered  liquid  will  be  nearly  colorless  and  perfectly  free  from  tannin.  The 
magnesia  in  solution  is  determined  in  an  aliquot  part  of  the  filtered  solu- 
tion, and  will  be  equivalent  to  the  total  free  acids  of  the  liquor  exclusive  of 
the  tannic  acid.  Another  portion  of  the  filtrate  is  evaporated  to  dryness, 
the  residue  gently  ignited,  moistened  with  carbonic  acid  water,  and  dried. 
It  is  then  boiled  with  distilled  water  and  the  solution  filtered.  The  carbon- 
ate of  magnesia  remaining  insoluble  represents  the  total  organic  acids,  and  can 
be  more  accurately  determined  by  converting  the  magnesia  into  pyrophos- 
phate  and  weighing.  If  these  total  organic  acids  be  calculated  in  terms  of 
acetic  acid,  and  the  previously  found  volatile  acids,  reckoned  as  acetic,  be  de- 

*  Allen,  Commercial  Organic  Analysis,  2d  ed.,  vol.  iii.  Part  i.  pp.  109-116. 
f  Horn,  Chem.  technische  Analyse  Organischer  Stoffe,  Wien,  1890,  p.  236. 
j  Allen,  Commercial  Organic  Analysis,  2d  ed.,  vol.  iii.  Part  i.  p.  119. 
|  Dingier,  Polytech.  Journ.,  256,  pp.  38  and  64. 


ANALYTICAL  TESTS   AND  METHODS. 


337 


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338  ANIMAL   TISSUES   AND   THEIR   PRODUCTS. 

ducted,  the  difference  represents  the  non-volatile  organic  acids.  The  magnesia 
remaining  in  the  filtrate  from  the  carbonate  of  magnesia  is  combined  as  sul- 
phate, and  when  determined  gives  the  sulphuric  acid  of  the  original  liquors. 
5.  ANALYSIS  OF  LEATHER. — It  is  possible  in  the  case  of  a  leather  to 
determine  the  percentage  of  moisture,  total  fats,  water-soluble  matter,  in- 
soluble fibre,  and  ash.  In  the  case  of  mineral  tannages,  the  quantitative 
determination  of  the  chief  constituents  of  the  ash  is  of  special  importance. 
The  fats  are  determined  by  extraction  in  a  Soxhlet  apparatus,  as  described 
in  a  previous  chapter,  carbon  disulphide  or  petroleum-ether  being  used  as 
solvent.  The  dry  leather  residue  remaining  after  this  extraction  is  digested 
for  some  hours  with  distilled  water  at  40°  C.  and  then  thoroughly  extracted 
by  fresh  water  at  the  same  temperature.  The  washings  are  then  brought 
to  fixed  volume  and  the  residue  determined  in  an  aliquot  portion.  Uncom- 
bined  tannin  may  also  be  determined  in  this  aqueous  extract  by  means  of 
the  hide-powder  or  Lowenthal  method.  The  total  ash  is  obtained  by 
igniting  a  separate  quantity  of  the  leather.  This  is  chipped  in  small  frag- 
ments and  ignited  gradually  in  small  portions  in  a  platinum  dish.  After 
the  leather  swells  and  carbonizes,  it  can  be  burned  completely  at  a  dull-red 
heat  without  loss  of  the  mineral  salts. 

B.  GLUE  AND  GELATINE  MANUFACTURE. 

Glue  is  a  decomposition  product  of  many  nitrogenous  animal  tissues. 
These  lose  on  heating  with  water  (analogous  to  starch-granules)  their  or- 
ganized structure,  swell  up,  and  gradually  go  into  solution.  The  solutions, 
even  when  very  dilute,  gelatinize  on  cooling,  forming  a  jelly,  which  dries 
to  a  horny  translucent  mass.  This  mass  is  glue  or  gelatine,  as  the  finer 
grades  are  termed.  It  dissolves  in  hot  water  to  a  liquid  possessing  notable 
cementing  power.  Neither  the  original  solution  obtained  from  the  nitro- 
genous tissues  nor  the  jelly  formed  from  it  on  cooling  have  any  cementing 
power.  This  is  only  acquired  when  the  jelly  has  dried  to  the  hard  mass 
known  as  the  glue.  Two  proximate  principles  seem  to  be  present  as  char- 
acteristic in  all  preparations  of  glue :  glutin,  obtained  chiefly  from  the  hide 
and  larger  bones,  and  chondrin,  from  the  young  bones  while  yet  in  the  soft 
state  and  the  cartilage  of  the  ribs,  and  joints.  Of  these,  the  former  much 
exceeds  the  latter  in  adhesive  power,  and  is  therefore  sought  to  be  obtained 
predominantly  in  the  glue  manufacture. 

I.  Raw  Materials. 

1.  HIDES  AND  LEATHER. — The  corium  of  the  animal  hides  (see  p. 
305)  is  the  most  important  glue-yielding  material  to  be  had.  Neither  the 
epidermis  nor  the  underlying  fat-tissue  contribute  to  the  glue  production, 
but  have  rather  an  injurious  effect  when  present.  What  is  known  as  "  glue- 
stock"  is  made  up  of  the  trimmings  from  the  ox,  sheep,  and  calf-skins,  the 
refuse  of  the  beam-house,  and  scraps  of  parchment  which  have  been  soft- 
ened and  unhaired  by  liming  and  are  in  condition  for  immediate  boiling. 
Of  still  greater  value  are  the  so-called  calves'  heads,  which  after  liming  and 
drying  form  a  special  article  of  commerce.  The  amount  of  glue  obtainable 
from  these  various  materials  varies  from  fifteen  to  sixty  per  cent.  Accord- 
ing to  Fleck,*  the  scraps  from  the  alum-tawing  process  yield  forty-five  per 

*  Die  Fabrikation  Chemischer  Producte,  etc.,  p.  60. 


PROCESSES   OF   MANUFACTURE.  339 

cent.,  those  from  the  ox-hides  thirty  per  cent.,  hare-  and  rabbit-skins  and 
parchment  trimmings  fifty  to  sixty  per  cent.,  foot  and  tail  pieces  of  oxen  fif- 
teen to  eighteen  per  cent.,  other  scraps  from  the  tanneries,  such  as  ear-laps  of 
sheep  and  cows,  sheep's  feet,  etc.,  thirty-eight  to  forty-two  per  cent.  Scraps 
of  bark-tanned  leather,  such  as  shoemaker's  and  saddler's  trimmings, 


are  also 
available  after  a  special  treatment  for  the  removal  of  the  tannin.    (See  p.  341 .) 

2.  BONES. — The  bones  contain  on  an  average  nearly  one-third  (32.2  per 
cent.)  of  their  weight  of  organic  constituents,  extracted  by  boiling  and  con- 
verted into  glue,  which,  however,  is  inferior  in  adhesive  power  to  that  pre- 
pared from  animal  skins.     The  soft  bones  of  the  head,  shoulders,  ribs,  legs, 
and  breast,  and  especially  deer's  horns  and  the  bony  core  of  the  horns  of 
horned  cattle,  yield  a  larger  quantity  of  glue  than  the  hard  thigh-bones 
and  the  thick  parts  of  the  vertebra,  which  are  principally  composed  of 
calcium  phosphate  and  require  a  more  prolonged  treatment  to  extract  the 
glue-making  constituents. 

3.  FISH-BLADDER. — The  inner  skin  of  the  air-bladders  of  the  several 
varieties  of  sturgeon  and  cod  furnishes  a  very  pure  glue  substance,  which 
on  account  of  its  purity  is  preferably  used  for  culinary  and  medicinal  pur- 
poses, and  is  known  as  "  isinglass."     It  is  inferior  in  adhesive  power  to 
hide-glue,  but  on  account  of  its  freedom  from  color,  taste,  and  odor,  and  its 
almost  perfect  solubility  in  hot  water,  commands  a  higher  price.     It  is  used 
for  food  preparations,  for  clarifying  wine,  beer,  and  other  liquids.     The 
chief  production  of  isinglass  is  from  the  sturgeon  in  Russia,  on  the  borders 
of  the  Caspian  and  the  Black  Sea. 

4.  VEGETABLE  GLUE. — Certain  species  of  algae  (Plocaria  tenax  and 
others)  found  in  Chinese  and  Japanese  waters  when  cleansed  and  boiled 
yield  a  product  known  under  the  several  names  of  "  Chinese  isinglass"  and 
"  agar-agar."     Of  similar  character  is  no  doubt  the  "  algin"  recently  ob- 
tained from  Scotch  algae  by  E.  C.  C.  Stanford.* 

n.  Processes  of  Manufacture. 

1.  MANUFACTURE  OF  GLUE  FROM  HIDES. — The  hide  trimmings  and 
offal,  if  in  the  fresh  state,  must  first  of  all  be  well  limed, — that  is,  treated 
with  milk  of  lime  in  pits  for  a  period  varying  from  ten  to  forty  days,  ac- 
cording to  the  character  and  source  of  the  hides,  the  lime  being  frequently 
renewed.  The  lime  softens  and  swells  the  hide-tissue,  saponifies  the  fats, 
and  dissolves  in  large  part  the  coriin,  blood,  and  flesh-particles  which  do 
not  form  glue.  The  glue-stock  is  then  thoroughly  washed  free  from  the 
lime,  lime  salts,  and  dirt,  usually  by  putting  it  in  nets  or  wicker  baskets 
which  are  suspended  in  running  water.  The  liming  also  serves  to  preserve 
the  glue-stock  in  case  it  is  not  to  be  immediately  worked  up.  After  wash- 
ing it  is  spread  out  to  dry.  The  lime  scum  from  the  pits  is  often  utilized 
in  fertilizer  manufacture.  Caustic  soda  has  also  been  used  instead  of  milk 
of  lime  for  this  treatment.  A  short  treatment  with  chloride  of  lime  im- 
mediately after  taking  the  stock  out  of  the  lime-pits  has  also  been  found  to 
give  the  glue  a  bright  color  and  excellent  adhesive  power.  In  recent  years 
sulphurous  acid  has  been  used  with  advantage  to  cleanse  and  prepare  the 
glue-stock,  as  it  bleaches  and  at  the  same  time  swells  the  hide,  at  least  as 
well  as  can  be  done  by  the  lime. 

•"'  Soc.  Chem.  Ind.  Jour.,  1884,  p.  297. 


340 


ANIMAL    TISSUES   AND   THEIR   PEODUCTS. 


FIG.  100. 


The  boiling  and  conversion  of  the  glue-stock  into  solution  may  be 
effected  by  heating  with  water  or  with  steam.  The  older  method  was  to 
place  the  glue-stock  in  large  kettles,  but  supported  upon  a  false  bottom  of 
perforated  metal,  and  adding  water  to  heat  it  by  direct  fire.  When  the 
whole  quantity  of  water  necessary  to  convert  the  hides,  etc.,  into  glue  solu- 
tion is  used  at  once,  the  drawback  is  encountered  that  the  gluten  which  first 
goes  into  solution  becomes  altered  by  the  prolonged  heating  and  loses  its 
adhesive  power.  This  can  be  obviated  somewhat  by  using  successive  smaller 
portions  of  water  and  drawing  them  off  as  they  become  saturated,  but  the 
last  portions  extracted  are  then  darkened  in  color.  The  use  of  steam,  either 
from  closed  pipes  or  direct  steam  from  perforated  pipes,  greatly  improves 
the  extraction,  shortening  the  time  required  and  improving  the  quality  of 
the  product.  A  form  of  boiler  for  this  glue  manufactured  by  the  aid  of 
steam  as  devised  by  Dr.  B.  Terne  is  given  in  Fig.  100.  Direct  high- 
pressure  steam  blown  into  closed 
vessels  has  been  found  to  be  quite 
effective  in  rapidly  melting  down 
the  glue- stock  and  producing  a 
concentrated  solution. 

The  use  of  vacuum-pans  and 
ttie  extraction  by  steam  under 
reduced  pressure  and  at  lower 
temperatures  has  also  been  found 
very  satisfactory  in  giving  a 
good  product  in  which  the  adhe- 
sive qualities  of  the  gluten  are 
in  no  way  impaired.  The  solu- 
tion must  be  freed  from  any 
melted  iat  and  lime  soaps  by 
skimming  and  from  suspended 
impurities  by  settling,  by  filter- 
ing through  linen  bags,  or  clari- 
fying by  the  use  of  bone-black. 
The  addition  of  alum  as  some- 
times practised  has  an  injurious 
effect  upon  the  adhesive  power 
of  the  product.  The  residue  of 
the  glue-stock  left  tmextracted  is 
pressed  out,  dried,  and  sold  as  a 
fertilizer  containing  about  four 
per  cent,  of  nitrogen.  The  clarified  glue  solution  is  poured  into  shallow 
wooden  moulds  some  six  inches  in  depth,  in  which  as  it  cools  it  gelatinizes 
to  a  brownish- yellow  jelly  containing  from  eighty  to  ninety  per  cent,  of 
water.  The  block  of  jelly  is  then  turned  out  upon  a  smooth  table,  pre- 
viously moistened  to  prevent  adherence,  and  sawed  by  horizontal  wires 
into  thin  slabs,  which  are  again  cut  by  vertical  wires  into  strips  of  the 
proper  width. 

The  drying  of  the  jelly  is  one  of  the  most  troublesome  parts  of  the 
whole  process,  as  it  must  take  place  rapidly  so  that  the  glue- making  mate- 
rial may  not  spoil,  as  it  is  very  prone  to  do  while  in  the  jelly  form,  and, 
on  the  other  hand,  the  heat  should  not  exceed  20°  C.  (68°  R).  Jt  may  take 
place  with  this  limitation  of  temperature  in  the  open  air,  if  the  air  is  not 


PROCESSES   OF   MANUFACTURE.  341 

too  moist  or  too  dry,  both  of  which  conditions  are  unfavorable.  It  is  now 
generally  effected  in  drying-rooms  in  which  a  current  of  warm  dry  air  at 
the  right  temperature  is  made  to  circulate.  As  the  surface  of  the  cakes 
after  drying  is  generally  rough  and  dull,  it  is  improved  in  appearance 
by  moistening  with  warm  water,  brushing  with  a  soft  brush,  and  again 
drying. 

2.  MANUFACTURE    OF   GLUE   FROM   LEATHER-WASTE-. — Before   at- 
temnting  to  boil  the  leather-waste  to  glue,  the  removal  of  all  traces  of 
tannic  acid  becomes  absolutely  necessary,  since  the  retention  of  the  smallest 
quantity  prevents  the  animal  tissue  from  dissolving  in  water.     The  waste 
must  therefore  be  comminuted  as  thoroughly  as  possible  to  facilitate  the 
complete  removal  of  the  tannic  acid.     This  is  done  frequently  in  the  "  hoi- 
lander"  used  for  paper-pulp,  and  the  washed  and  ground  leather- waste  then 
heated  in  a  pressure-boiler  under  a  pressure  of  two  atmospheres  with  fifteen 
per  cent,  of  its  weight  of  slaked  lime.    After  thorough  washing  the  residue 
is  ready  for  use  as  glue-stock. 

3.  MANUFACTURE   OF   GLUE   OR   GELATINE    FROM    BONES. — Two 
methods  have  been  followed  for  the  extraction  of  gelatine,  as  the  product 
is  generally  called  in  this  case,  from  bones.     The  bones  are  either  boiled 
under  pressure,  or  they  are  treated  with  hydrochloric  acid  to  remove  the 
calcium  phosphate  and  afterwards  boiled  for  the  extraction  of  the  gelatine. 
The  bones  in  either  case  are  with  advantage  deprived  of  their  fat  first, 
which  is  done  either  by  heating  them  with  water  and  steam  in  boiler-shaped 
vessels,  when  the  fat  rises  and  can  be  skimmed  off  from  the  water,  or  in 
closed  vessels  with  volatile  solvents  like  petroleum-benzine  and  carbon  di- 
sulphide.      The  older  process  of  extracting  the  gelatine  by  boiling  the 
powdered  bones  with  water  under  pressure  decomposes  a  portion  of  the 
valuable  material,  and  is  now  generally  replaced  by  the  method  of  treat- 
ment with  hydrochloric  acid  for  the  removal  of  the  calcium  phosphate. 
The  crushed  bones  are  placed  in  wooden  vats  with  dilute  hydrochloric  acid 
of  specific  gravity  1.05  (forty  litres  of  acid  to  ten  kilos,  of  bones)  and 
allowed  to  remain  for  several  days.      They  are  then  placed  in  lime-water 
for  a  time,  well  washed,  and  boiled  eight  to  ten  hours  with  a  large  excess  of 
water,  or  converted  more  rapidly  into  gelatine  solution  by  the  aid  of  steam. 
The  resulting  solution  is  filtered  through  cloth,  bleached  by  sulphurous 
oxide,  and  poured   into  forms  to  gelatinize.      The  manufacture  of  bone 
gelatine  is  frequently  combined  with  the  fertilizer  manufacture,  as  the  cal- 
cium phosphate  extracted  by  the  hydrochloric  acid  treatment  contains  from 
eighteen  to  twenty  per  cent,  of  phosphoric  acid.     The  newer  method  of  ex- 
tracting the  fat  by  volatile  solvents  yields  five  to  six  per  cent,  of  fat  with- 
out injury  to  the  gelatine  of  the  bones,  while  the  older  method  of  boiling 
out  the  fat  yields  from  three  to  four  per  cent,  only  and  tends  to  lessen  the 
yield  of  gelatine. 

4.  MANUFACTURE  OF  FISH  'GELATINE. — The  swimming-bladders  of 
the  fish  are  taken  and  thoroughly  washed  in  water  from  all  fatty  and  bloody 
particles.     They  are  then  removed  and  cut  longitudinally  into  sheets,  which 
are  exposed  to  the  sun  and  air  to  dry,  with  the  outer  face  turned  down,  upon 
the  boards  of  linden  or  bass-wood.     The  inner  face  of  the  bladders  is  pure 
isinglass,  which  when  partially  dried  can  with  care  be  removed  from  the 
outer  muscular  layer.     The  isinglass  layer,  possessing  a  silvery  white  lustre, 
is  taken  either  in  sheets,  rings,  or  horseshoe-shaped  strips,  etc.,  bleached  with 
sulphurous  acid,  and  then  thoroughly  dried. 


342  ANIMAL   TISSUES   AND   THEIR   PRODUCTS. 

A  product  distinct  from  isinglass  and  known  as  fish  glue  is  prepared  by 
boiling  the  skin  and  muscular  tissue  of  fish,  and  more  resembles  ordinary 
hide  glue  in  its  adhesive  properties,  but  is  offensive  in  odor.  It  is  prepared 
from  the  scales  and  skins  of  large  fish  like  the  carp  by  acting  on  them  with 
hydrochloric  acid  as  upon  bones  and  then  extracting  with  water. 

m.  Products. 

1.  HIDE  GLTJE  is  the  variety  which  shows  most  strongly  the  adhesive 
property,  and  hence  is  that  manufactured  for  joiner's  and  carpenter's  use. 
Its  color  may  vary  considerably  without  any  impairing  of  its  adhesive 
power.     It  is  rarely  perfectly  colorless  or  transparent.     A  gray  to  amber  or 
brown-yellow  color  and  translucent  or  partially  opaque  appearance  is  more 
usual.     It  should  be  clear,  dry,  and  hard,  and  possess  a  glassy  fracture. 
It  should  swell  up  but  not  dissolve  in  cold  water,  but  dissolve  in  water  at 
62.5°  C.  (144.5°  F.).     Inorganic  substances  (such  as  white  lead)  are  inten- 
tionally introduced  into  some  varieties,  such  as  the  Russian  glue,  without 
injury  to  their  adhesive  power. 

The  variety  known  as  "  Cologne  glue"  is  manufactured  from  scrap  hide, 
which  after  liming  is  carefully  bleached  in  a  chloride  of  lime  bath  and 
then  thoroughly  washed. 

"  Russian  glue,"  as  stated,  contains  some  inorganic  admixture.  It  is  of 
a  dirty- white  color,  and  contains  from  four  to  eight  per  cent,  of  white  lead, 
chalk,  zinc-white,  or  barytes. 

"  Size  glue"  and  "  Parchment  glue"  are  both  skin  glues  prepared  with 
special  care. 

2.  BONE  GLUE  (OB  BONE  GELATINE). — Bones  yield  a  product  of  less 
adhesive  power  than  the  glue  of  skins  and  tendons,  but  when  carefully 
worked  the  product  is  clearer  and  is  free  from  offensive  odor.     It  is  there- 
fore much  used  for  culinary  purposes  and  for  medicinal  applications,  and  for 
fining  or  clarifying  beer,  wine,  and  other  liquids  it  has  largely  superseded 
isinglass.     The  gelatine  thus  used  must,  however,  be  absolutely  tasteless  and 
free  from  odor. 

Bone  gelatine  is  now  made  use  of  very  largely  in  the  manufacture  of 
gelatine  capsules,  etc.,  for  medicinal  uses,  of  court^plaster  for  applying  to 
wounds,  and  of  gelatine  emulsions  with  bromide  and  chloride  of  silver  for 
coating  the  photographic  dry  plates.  Mixed  with  glycerine  it  makes  an 
elastic  mass  used  for  printer's  rolls,  for  hectographs,  etc. 

"  Patent  Glue"  is  a  very  pure  variety  of  bone  glue  of  deep  dark-brown 
color.  It  is  very  glossy  and  swells  up  very  much  in  water. 

3.  ISINGLASS  (OR  FISH  GELATINE). — This  is  the  finest  and  best  of  ani- 
mal glues.     The  best  isinglass  should  be  pure  white,  nearly  transparent,  dry 
and  horny  in  texture,  and  free  from  smell.     It  dissolves  in  water  at  from 
35°  to  50°  C.  (95°  to  122°  F.)  without 'any  residue,  and  in  cooling  should 
produce  an  almost  colorless  jelly.     The  commercial  varieties  of  isinglass 
are  the  Russian  (the  best  coming  from  Astrachan),  North  American  (or  New 
York),  East  Indian,  Hudson's  Bay,  Brazilian,  and  German  (or  Hamburg). 

4.  LIQUID  GLUE. — By  the  action  of  nitric  or  acetic  acid  upon  a  solu- 
tion of  glue  its  power  to  gelatinize  may  be  completely  arrested  while  its 
adhesive  power  is  not  at  all  interfered  with.     Thus,  if  one  kilo,  of  glue  is 
dissolved  in  one  litre  of  water  and  .2  kilo,  of  nitric  acid  of  36°  B.  be  added, 
after  the  escape  of  the  nitrous  fumes  we  have  a  solution  that  will  not  gela- 


BIBLIOGKAPHY   AND   STATISTICS.  343 

tinize  on  cooling,  although  it  has  the  full  adhesive  power  of  the  glue.  Four 
parts  of  transparent  gelatine,  four  parts  of  strong  vinegar,  one  part  of 
alcohol,  and  a  small  amount  of  alum  will  also  yield  an  excellent  liquid 
glue. 

IV.  Analytical  Tests  and  Methods. 

The  nature  of  glue  makes  it  rather  a  question  of  physical  and  mechani- 
cal tests  as  to  quality  of  a  given  sample  than  of  chemical  tests. 

1.  ABSORPTION  OF  WATER. — Thus  the  relative  amount  of  water  that 
a  given  sample  will  take  up  when  laid  in  cold  water  is  regarded  as  a  moder- 
ately fair  criterion  of  its  quality.     A  weighed  sample  is  laid  for  twenty-four 
hours  in  cold  water  (not  exceeding  12°  C.  (53.4°  F.)  in  temperature),  and 
at  the  expiration  of  that  time  the  excess  of  water  having  been  poured  off, 
the  jelly  is  weighed.     Very  good  varieties  (white  gelatine  prepared  from 
bones)  will  take  up  thirteen  times  the  quantity  of  water  in  gelatinizing, 
second  quality  glue  ten  times,  and  inferior  grades  only  about  six  times  the 
amount  of  water.     At  the  same  time  the  consistency  of  the  jelly  formed  must 
also  be  taken  into  consideration.     A  firm  jelly  produced  by  the  absorption 
of  a  large  quantity  of  water  indicates  a  glue  of  the  best  quality. 

Two  observations  are  of  value  in  this  connection  :  first,  glue  twice  dis- 
solved and  again  dried  is  capable  of  drying  out  more  thoroughly  and  of 
showing  water-assimilating  properties  on  redissolving  more  fully  than  glue 
obtained  by  a  single  drying ;  and,  second,  that  hide  glue  on  taking  up 
smaller  quantities  of  water  becomes  very  soft  and  more  difficult  to  weigh 
accurately  than  bone  glue,  which,  with  larger  amounts  of  absorbed  water, 
still  forms  a  firm  jelly.  This  difference  in  behavior  alone  is  capable  of 
giving  an  indication  of  the  source  of  the  glue. 

2.  INORGANIC  IMPURITIES. — The  presence  of  inorganic  salts,  as  in  the 
case  of  Russian  glue,  can  be  determined  by  the  use  of  the  appropriate 
reagents,  and  the  amount  also  quantitatively  determined. 

3.  ADULTERATION  OF  ISINGLASS  WITH  GLUE. — Isinglass  is  sometimes 
adulterated  by  rolling  up  sheets  of  gelatine  (bone  gelatine)  between  the  lay- 
ers of  true  isinglass  and  drying  them  in  this  condition. 

Redwood  and  Letheby  have  observed  that  the  ash  of  pure  isinglass  does 
not  exceed  .9  per  cent.,  while  glue  contains  from  two  to  four  per  cent,  of 
ash.  An  adulterated  sample  of  isinglass  gave  Letheby  1.5  per  cent,  of  ash. 

On  heating  with  water,  true  isinglass  gives  only  a  peculiar  fish  or  algae 
odor,  while  the  adulterated  isinglass  gave  a  strong  glue-like  odor  at  once 
recognizable. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

ON    LEATHER. 

1869. — Die  Gerberinde,  J.  G.  Neubrand,  Frankfort. 

1873. — Die  Rohstoffe  des  Pfianzenreicb.es,  J.  Wiesner,  Leipzig. 

1875. — Herstellung  des  Leders  in  ibren  chemiscben  Vorgangen,  J.  C.  H.  Lietzmann,  Berlin. 

1876. — Leather  Manufacture,  J.  S.  Schultz,  New  York. 

1877. — Die  Weissgerberei,  etc.,  F.  Wiener,  Leipzig. 

Leder-Industrie-Bericht  iiber  die  Austellung  in  Philadelphia,  W.  Eitner,  Vienna. 
1880.— Classification  de  300  Matieres  tannantes,  R.  J.  Bernardin,  Gand. 

Die  Gerberinden,  F.  R.  von  Hohnel,  Berlin. 


344 


ANIMAL   TISSUES   AND   THEIR   PRODUCTS. 


1880.— The   Culture  of  Sumach,   Department   of  Agriculture,    Special   Keport   26,   W. 

McMurtrie,  Washington. 

1881. — Matieres  premieres  organiques,  Geo.  Pennetier,  Paris. 
1882. — Die  Grundziige  der  Lederbereitung,  Chr.  Heinzerling,  Braunschweig. 
1885. — Bericht  der  Commission  der  Gerbstoffbestimmung,  etc.,  C.  Councler,  Cassel. 

Text-book  of  Tanning,  H.  K.  Procter,  London  and  New  York. 
1886. — Cuirs  et  Peaux,  Tannage,  etc.,  H.  Villain,  2me,  Paris. 
1888. — Abriss  der  chemischen  Technologic,  Chr.  Heinzerling,  Berlin. 
1889. — Handbuch  der  technisch-chemischen  Untersuchungen,  6te  Auf.,  Bolley,  Leipzig 

Haiid-book  of  Commercial  Geography,  Geo.  Chisholm,  London  and  New  York 

Traite  pratique  de  la  Fabrication  des  Cuirs,  etc.,  A.  M.  Villon,  Paris. 
1890. — Lehrbuch  der  technischen  Chemie,  H.  Ost,  Berlin. 

Die  Lohgerberei,  F.  Wiener,  2te  Auf,  Leipzig. 
1891. — Leather  Manufacture,  J.  W.  Stevens,  London. 
1892.— Industrie  des  Cuirs  et  des  Peaux,  T.  Jean,  Paris. 

The  Tannins,  vol  i.,  Henry  Trimble,  Philadelphia. 
1894. — Cuirs  et  Peaux,  Voinesson  de  Lavelines,  Paris. 

The  Tannins,  vol.  ii.,  Henry  Trimble,  Philadelphia. 

ON   GLUE   AND   GELATINE. 

1871.— Die  Leimfabrikation,  C.  Hagen,  Berlin. 

1878. — Die  Fabrikation  chemischer  Producte  aus  thierischen  Abfallen,  H.  Fleck,  Braun- 
schweig. 

1879. — Die  Leim  und  Gelatine  Fabrikation,  2te  Auf,  F.  Davidowsky,  Vienna. 
1884. — Die  Verwerthung  der  Knochen  auf  chem.  Wege,  W.  Friedberg,  Vienna. 

Glue  and  Gelatine,  Davidowsky,  translated  by  H.  Brannt,  Philadelphia. 
1891. — Praktisches  Lehrbuch  der  Lohgerberei,  S.  Kas,  Weimar. 
1893. — Cements,  Pastes,  Glues,  and  Gums,  H.  C.  Standage,  London. 

Die  Herstellung  der  Lohgaren  Leder,  L.  Hoffmann,  Weimar. 
1896. — Anleitung  zur  Mikrochemischen  Analyse,  2te  Heft  (Die  wichtigsten  Faserstoffe), 

H.  Behrens,  Leipzig. 
1897. — The  Art  of  Leather  Manufacture,  Alexander  Watt,  4th  ed.,  London. 

The  Manufacture  of  Leather,  C.  T.  Davis,  2d  ed.,  Philadelphia. 

Sizing  Ingredients,  Size  Mixing,  etc.,  H.  Monie,  Jr.,  London. 
1898. — Leather  Industries  Laboratory  Book,  H.  K.  Procter,  London. 
1900. — Leather- Worker's  Manual,  H.  C.  Standage,  London, 


STATISTICS. 

1.    IMPORTATIONS    OF    TANNING    MATERIALS    INTO    THE    UNITEI> 
STATES.  — 


Gambier,  or  terra  Japonica, 

pounds  ........  29,022,203 

Valued  at     .......      $963,255 

Sumac  (ground),  pounds  .    .  12,179,203 

Valued  at     .......      $235,157 


1896. 

32,338,264 

$1,108,611 

13,432,041 

$232,570 


1897. 

31,349,545 

$959,501 
18,688,635 

$248,048 


1898. 

42,334,590 

$1,021,341 

8,301,235 

$120,205 


38,123,478 
$754,497 

12,975,970 
$183,136 


2.  IMPORTATIONS  OF  TANNING  MATERIALS  INTO  GREAT  BRITAIN.  — 

1895. 
Cutch  and  gambier,  tons  .    .       25,545 

Valued  at     .......  £556,120 

Valonia,  tons  .......       35,605 

Valued  at     .......  £395,943 


1896. 

1897. 

1898. 

1899. 

26,844 

25,048 

19,504 

21,526 

£549,256 

£418,128 

£304,808 

£347,025 

31,605 

29,637 

25,882 

24,336 

£319,798 

£300,324 

£270,802 

£281,471 

3.  IMPORTATIONS  OF  TANNING  MATERIALS  INTO  GERMANY.  — 


Metric  tons. 

Catechu 5,719 

Divi-divi 6.633 

Gallnuts 2^418 

Myrobalans  .    5,070 

Quebracho-wood   .    .  39,016 
Tanning  extracts  .    .    9,246 


1894. 

1897. 

1898. 

1899. 

Metric  tons. 

Metric  tons. 

Metric  tons. 

Metric  tons. 

5,969 

5,791 

6,487 

7,237 

4,874 

9,315 

7,140 

8,522 

3,059 

2,462 

2,869 

2,497 

7,911 

10,230 

10,884 

9,945 

40,175 

81,497 

113,506 

80,298 

11,313 

17,472 

22,934 

28,959 

BIBLIOGRAPHY   AND   STATISTICS. 


345 


4.  UNITED    STATES    IMPORTATIONS   OF   HIDES    AND    SKINS,   RAW 
AND  TANNED. — 


Goat-skins,  pounds  .    .    . 

Valued  at 

All  other  skins,  pounds  . 

Valued  at      . 

Skins  for  morocco  leather, 

valued  at    .    .  J 

Upper  leather,  valued  at . 

Gloves    of   kid   or  other 

leather,  valued  at .    . 


1895. 

53,968,385 
$10,894,845 
170,977,644 
$15,067.104 

$3,728,255 
$2,351,156 


46,747,029 
$10,304,395 
163,650,982 

$20,215,782 

$3,145,989 
$2,384,263 


1897. 

49,868,020 
$11,328,162 
156,232,824 

$16,534,864 

$3,716,259 
$2,410,862 


64,923,487  69,728,945 
$15,776,601  $18,488,326 
180,851,129  197,361,805 
$21,292y33U  $23,499,717 

$3,081,770      $2,455,332 
$2,210,937      $2,470,841 


$6,463,872     $6,763,082     $6,486,813     $5,384,168      $5,398,125 


The  following  figures  of  importations  of  goat-skins  at  the  ports  of 
New  York  and  Philadelphia,  with  localities  from  which  they  are  brought, 
were  presented  to  the  "  Morocco  Manufacturers'  National  Association"  at 
their  annual  meeting,  July  11,  1895. 


ARRIVALS   AT    NEW    YORK. 


1892. 

First  6  months. 
Skins. 

Mexican  ....  .  937,872 
Texas  and  Mexican 

frontier 493,400 

Curaqoa 257,300 

Maracaibo,  Rio  Hacha, 

Porto    Cabello,    and 

Laguayra 59,500 

Brazil 1,504,200 

Buenos  Ayres  ....  436,200 

Payta 145,500 

Oajaca 73,978 

West  Indies 81', 125 

Bogota 19,680 

Angostura 2,460 

European,  Asiatic,  and 

African 2,899,000 

Arabian 082,000 

Calcutta 2,363,500 


First  6  months, 
iskins. 

910,201 

261,700 
413,300 


63,600 

1,231,200 

273,000 

409,7^0 

94,236 

94,500 

37,920 

6,450 

2,868,300 
1,6155,250 
2,614,000 


1894. 

First  6  months. 
Skins. 

896,400 

309,400 

428,800 


70,300 

1,371,000 

694,  r.  00 

478,000 

51,600 

78,625 

30,000 

4,360 

2,061,300 
1,667,500 
2,152,500 


AT   PHILADELPHIA. 


European,  Asiatic,  and 

African 875,700 

Arabian 45,(X>0 

Calcutta 639,000 


1,347,300 

14,500 

804,500 


598,900 

34,250 

157,500 


1895. 

First  6  months. 
Skins 

773,000 

427,100 
418,500 


60,300 

1,613,700 

373,200 

208,800 

59,000 

72,- -.00 

13,4  0 

1,890 

4,225,375 
1,422,750 
3,497,000 


10,156,715   10,843,407   10,194,385   13,166,555 


1,490,875 

44,000 

862,000 


1,559,700    2,166,300     790,650    2,396,875 


5.  UNITED  STATES  EXPORTATION  OF  LEATHER. — 


1895.       1896.  1897.  1898.  1899. 

Sole-leather,  pounds    .    .    .  45,364,349  41,818,503  38,384,314  37,813,019  37,120,912 

Valued  at              .    .    .    .$6,919,372  $7,474,021  $6,510,404  $6,644,553  $6,280,904 
Buff,     grain,     and     upper 

leather,  valued  at .          $6,038,940  $9,273,315  $9,107,053  $10,293,430  $12,353,995 

All  other  leather,  valued  at     $682,241  $1,017,649  $813,798  $858,421  $1,090,574 


346  ANIMAL   TISSUES  AND   THEIR  PRODUCTS. 

6.  ENGLISH  IMPORTATIONS  OF  HIDES. — 

1895.                    1896.                    1897.                    1898.  1899. 

Hides,  dry,  cwt 491,547           369,063           556,587           542,454  446,285 

Valued  at £1,153,757        £905,427     £1,413,166     £1,455,806  £1,148,652 

Hides,  wet,  cwt 771,133          604,728           638,658          694,057  764,240 

Valued  at £1,650,369     £1,319,501     £1,336,988     £1,450,260  £1,641,514 

English  Exportations  of  Leather. — 

1895.        1896.        1897.        1898.  1899. 

Leather,  un wrought,  cwt.         159,037           138,069           157,892           159,399  155,002 

Valued  at £1,422,747     £1,279,702     £1,389,311     £1,422,508  £1,473,294 

7.  EXPORTATIONS  OF  GLUE  FROM  THE  UNITED  STATES. — 

1895.        1896.        1897.        1898.  1899. 

Glue,  pounds 1,178,328       1,760,470       1,400,863      2,318,711  2,368,087 

Valued  at $114,493        $166,930        $132,581        $209,441  $222,072 


RAW  MATERIALS.  347 


CHAPTER  XI. 

INDUSTRIES   BASED  UPON  DESTRUCTIVE   DISTILLATION. 

DESTRUCTIVE  distillation  has  been  denned  as  "  the  decomposition  of  a 
substance  in  a  close  vessel  in  such  a  manner  as  to  obtain  liquid  products." 
It  must  be  observed  here  that  the  word  product  is  used  to  indicate  some- 
thing not  originally  present  in  the  substance  distilled.  A  body  may  be 
obtained  in  the  liquid  distillate  which  has  merely  been  driven  over  by  heat 
and  which  already  existed  in  the  original  material  in  physical  or  mechani- 
cal admixture.  Such  a  body  is,  to  speak  exactly,  an  educt  and  not  a  product. 

The  substances  which  are  submitted  to  destructive  distillation  are  in  the 
main  solids,  as  most  classes  of  liquids  are  capable  when  heated  with  care  of 
volatilization  without  decomposition,  although  such  liquids  as  fatty  oils, 
glycerine,  etc.,  are  decomposed  if  distilled  under  normal  atmospheric  press- 
ure. (The  cracking  of  petroleum  is  another  illustration  of  destructive  dis- 
tillation of  a  liquid  purposely  brought  about.)  With  solids,  on  the  other 
hand,  it  is  the  exception  rather  than  the  rule  to  find  one  capable  of  melting 
and  vaporizing  unchanged  in  composition  when  distilled  under  normal 
atmospheric  pressure.  The  same  solid,  moreover,  if  of  at  all  complex  molec- 
ular composition,  may  decompose  quite  differently  and  yield  different  sets 
of  products  according  to  the  conditions  which  govern  the  distillation.  The 
most  important  of  these  modifying  conditions  is  that  of  temperature.  "  Low 
temperature"  distillation  and  "high  temperature"  distillation  as  practised 
upon  the  same  material  (wood  or  coal,  for  example)  may  yield  quite  differ- 
ent results.  The  physical  condition  or  mechanical  subdivision  of  the  sub- 
stance also  has  an  influence,  although  a  subordinate  one,  upon  the  nature  of 
the  products.  Solids,  upon  the  destructive  distillation  of  which  important 
industries  are  founded,  are  wood,  coal,  shales,  bones,  and  animal  refuse. 
The  distillation  of  shale  has  already  been  considered  in  connection  with  the 
mineral  oil  industry.  (See  p.  27.)  The  other  industries  will  now  be 
noted  in  succession. 

A.  DESTRUCTIVE  DISTILLATION  OF  WOOD. 
I.  Raw  Materials. 

1.  COMPOSITION  OF  WOOD. — The  wood  which  is  to  be  destructively 
distilled  is  composed,  we  may  say  in  general  terms,  of  woody  fibre  and 
plant-juice  or  sap,  which  is  an  aqueous  solution  of  the  substances,  both 
nitrogenous  and  non-nitrogenous,  which  serve  as  the  food  for  the  living 
plant.  The  woody  fibre  is  made  up  primarily  of  cellulose,  which  is  in  part 
changed  into  "  lignin,"  as  the  incrusting  substance  is  called.  In  percentage 
composition  this  latter  substance  differs  from  the  pure  cellulose  in  contain- 
ing more  carbon  and  less  oxygen  and  hydrogen.  The  amount  of  incrusting 
material  varies,  being  more  abundant  in  hard  and  heavy  varieties  than  in 
light  and  soft  kinds,  and  wood  which  contains  it  in  the  largest  proportion 


348     INDUSTRIES  BASED   UPON   DESTRUCTIVE  DISTILLATION. 


gives  the  most  acid  and  naphtha  on  distillation.  The  amount  of  water 
present  in  wood  also  varies  not  only  according  to  the  season  of  the  year,  but 
also  quite  widely  in  different  woods  cut  at  the  same  season.  Thus,  the 
following  table  of  Schiibler  and  Hartig  shows  the  percentage  of  water  of 
different  trees  taken  at  the  period  of  minimum  amount : 


Per  cent,  of  water. 

Beech 18.6 

Willow 26.0 

Maple 27.0 

Elder 28.3 

Ash 28.7 

Birch 30.8 

White  hawthorn 32.3 

Oak 34.7 

White  fir 37.1 


Per  cent,  of  water. 

Horsechestnut 38.2 

Pine 39  7 

Alder 41.6 

Elm 44.5 

Lime 47.1 

Lombardy  poplar 48.2 

Larch  . 48.6 

White  poplar 50.6 

Black  poplar  ...    ....    51.8 


2.  EFFECT  OF  HEAT  UPON  WOOD. — The  effect  of  heat  upon  wood  in 
the  absence  of  air  is  a  matter  which  is  to  be  carefully  noted  as  throwing 
light  upon  the  results  obtained  in  destructive  distillation.  It  of  course  dif- 
fers radically  from  the  result  of  heating  with  free  contact  of  air.  Violette 
found  that  when  wood  was  carefully  and  slowly  heated  no  decomposition 
occurred  under  150°  C.,  water  only  being  given  off;  between  150°  and 
160°  C.  the  loss  was  two  per  cent,  of  the  weight  of  the  water-free  wood; 
between  160°  and  170°  C.,  5.5  per  cent. ;  between  170°  and  180°  C., 
11.4  per  cent.,  and  so  on  until  at  280°  C.  63.8  per  cent,  of  volatile  prod- 
ucts had  been  driven  off  and  36.2  per  cent,  only  of  the  water-free  wood 
remained  in  the  retort.  The  products  given  off  in  this  period  of  heating 
between  150°  and  280°  are  the  valuable  liquid  products  known  as  pyrolig- 
neous  acid  (acetic  acid  and  its  homologues),  wood-naphtha  or  methyl  alcohol, 
methyl  acetate,  acetone,  furfurol,  the  mixture  of  phenols  known  collectively 
as  "wood-creosote,"  and  other  bodies  of  empyreumatic  and  tarry  odor. 
These  bodies  differ,  as  will  be  seen  later  in  very  important  respects,  from 
coal-tar  products.  Above  280°  C.,  the  decomposition  proceeds  somewhat 
differently,  hydrocarbons,  both  gaseous  and  liquid,  being  formed.  The  ad- 
ditional percentage  of  loss  by  weight  between  280°  and  350°  C.  is  only 
6.5  per  cent,  of  the  water-free  wood,  but  it  makes  from  eighty  to  ninety 
volumes  of  gas.  The  decomposition  continues  from  350°  to  430°  C., 
when  the  total  loss  by  weight  amounts  to  eighty-one  per  cent,  of  the  water- 
free  wood.  The  products  obtained  within  these  limits  of  temperature  are 
largely  solid  hydrocarbons  like  paraffin  and  high  temperature  products  like 
benzene  and  toluene,  naphthalene,  phenol  and  cresol.  From  430°  to 
1500°  C.  the  additional  loss  of  weight  is  only  1.7  per  cent.  We  may  sum 
up  these  results  by  saying  that  three  periods  may  be  distinguished  broadly 
for  this  decomposition  of  wood  by  heat:  first,  from  150°  to  280°  C.,  the 
period  of  watery  acid  products ;  second,  from  280°  to  350°  C.,  the  period 
of  gaseous  products ;  and,  third,  from  350°  to  430°  C.,  the  period  of  liquid 
and  solid  hydrocarbons.  Violette  found  also  great  difference  in  the  re- 
sults according  as  the  temperature  was  slowly  raised  or  as  the  wood  was 
rapidly  brought  up  to  a  higher  heat.  Thus,  one  hundred  parts  by  weight 
of  wood  slowly  heated  so  that  the  temperature  of  432°  C.  was  only  reached 
after  six  hours  left  18.87  parts  of  charcoal,  while  one  hundred  parts  of 
the  same  wood  put  into  a  retort  previously  heated  to  432°  C.  left  only  8.96 
parts  by  weight  of  charcoal. 


PROCESSES  OF  MANUFACTURE. 


349 


n.  Processes  of  Manufacture. 

1.  DISTILLATION  OF  THE  WOOD. — The  primitive  method  of  distilling 
wood  devised  by  the  charcoal-burners,  in  which  the  wood  was  piled  up  in 
large  heaps  covered  in  by  clay  and  turf  so  as  to  form  a  circular  dome-shaped 
mound,  is  still  followed  in  some  heavily-wooded  districts.  Of  course  the 
charcoal  is  the  only  product  sought  in  this  case,  and  the  gaseous  and  liquid 
products  of  the  distillation  are  allowed  to  escape.  In  Russia  and  Sweden 
the  charcoal-burning  in  mounds  is  now  frequently  combined  with  the  col- 
lection of  the  tar,  which  as  it  condenses  is  made  to  flow  through  inclined 
troughs,  and  is  drawn  off  from  below.  In  this  way  the  valuable  birch-bark 
tar  (see  p.  334)  and  kienoel  (Russian  turpentine  oil)  are  obtained.  For  a 
proper  collection  of  all  the  products  of  the  destructive  distillation  of  wood, 
however,  it  is  essential  that  the  distillation  be  carried  out  in  retorts  provided 
with  proper  condensation  apparatus.  These  retorts  may  be  either  set  in 
horizontal  or  vertical  position,  and  may  be  either  fixed  or  capable  of  re- 
moval for  emptying  and  re-charging.  It  is  found  convenient  in  large  works 
where  it  is  desirable  to  carry  on  the  distillation  continuously  to  have  a  series 
of  retorts  connected  with  one  and  the  same  condensation  apparatus  and 

FIG.  101. 


heated  by  the  same  flues.  Such  an  arrangement  of  retorts  is  shown  in  Fig. 
101.  This  arrangement  allows  of  the  removal  and  re-charging  of  a  single 
retort  without  interrupting  the  working  of  the  others.  The  heating  should 
be  conducted  slowly  at  first  so  that  the  maximum  yield  of  the  low  tem- 
perature products,  acetic  acid  and  methyl  alcohol,  may  be  obtained,  then 
increased  until  the  gas  comes  off  freely,  and  at  the  end  of  this  stage  of 


350     INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

the  decomposition  again  strengthened  to  drive  over  the  high  temperature 
products  characteristic  of  the  last  period  of  distillation.  As  the  maximuro 
temperature  needed  is  beyond  the  record  of  the  mercury  thermometer,  a 
pyrometer  can  be  used  or  a  small  bar  of  metallic  antimony  which  melts  at 
432°  C.  taken  as  indicator.  Superheated  steam  has  also  been  used  as  a 
means  of  accurately  controlling  the  application  of  heat  in  the  distillation, 
and  it  is  said  that  the  majority  of  European  works  manufacturing  charcoal 
for  gunpowder  purposes  use  this  method  of  distillation.  The  liquid  which 
runs  oif  from  the  condenser  is  at  first  wax-yellow  in  color,  but  becomes 
dark-colored,  reddish-brown,  and  eventually  nearly  black  and  quite  turbid. 
When  allowed  to  stand  at  rest  it  soon  separates  in  two  sharply  distinct 
layers, — the  lower  one  of  a  thick  tar,  dark  or  perfectly  black  in  color, 
and  the  upper  one,  which  is  much  the  larger  in  amount,  is  the  crude  pyro- 
ligneous  acid  and  is  reddish-yellow  or  reddish-brown  in  color.  A  light 
film  of  oil  often  covers,  in  part  at  least,  this  watery  layer  and  represents 
the  benzene  hydrocarbons  produced.  We  have  already  noted  the  fact  that 
the  yield  of  liquid  products  was  affected  greatly  by  the  temperature  used 
for  distillation.  Different  varieties  of  wood  also  vary  somewhat  in  the 
results  obtained,  even  when  distilled  under  the  same  conditions  of  tempera- 
ture. This  is  illustrated  in  the  following  few  examples  :  * 


Charcoal. 

Tar. 

Crude  pyro- 
ligneous 
acid. 

Containing 
actual  acid. 

Gases. 

T?  A  v.      i,  f  slowly  heated  .... 
Redbeech|  rapidly  heated     .    .    . 
I,,    if  slowly  heated          .... 

26.7 
21.9 
29.2 
21.5 
34.7 
27.7 
30.3 
24.2 

5.9 
4.9 
5.5 
3.2 
3.7 
3.2 
4.4 
9.8 

45.8 
39.5 
45.6 
39.7 
44.5 
42.0 
41.0 
42.0 

5.2 
3.9 
5.6 
4.4 
4.1 
3.4 
2.7 
2.4 

21.7 
33.8 
19.7 
35.6 
17.2 
27.0 
24.4 
24.1 

h  \  rapidly  heated     

/-v  i    f  slowly  heated  . 

'    \  rapidly  heated     

-o«         f  slowly  heated 

e    \  rapidly  heated 

Beech-wood  and  foliage  trees  in  general  yield  distinctly  more  acid  than 
coniferous  trees,  but  the  latter  yield  more  tar  of  terebinthinate  character.  The 
figures  given  above,  it  must  be  remembered,  however,  were  gotten  in  experi- 
ments with  small  portions.  In  practice,  working  with  larger  quantities,  the 
yield  of  several  of  the  products  is  notably  larger.  The  yield  of  wood-spirit, 
or  methyl  alcohol,  varies  from  five-tenths  to  one  per  cent,  of  the  weight  of 
the  dry  wood. 

The  emptying  of  the  retorts,  if  done  as  intended  while  the  charcoal  is 
yet  glowing,  involves  the  use  of  air-tight  pits  into  which  the  charcoal  can 
be  emptied  from  the  retorts  and  immediately  covered  with  moist  charcoal- 
powder  to  prevent  loss  by  combustion.  A  form  of  apparatus  for  distilling 
the  sawdust  so  abundantly  produced  in  wood-working  processes  has  been  de- 
vised by  Halliday,  of  Salford,  England,  and  is  said  to  work  satisfactorily  in 
practice.  It  is  shown  in  Fig.  102.  It  consists  of  a  horizontally  placed 
cylindrical  retort,  A9  within  which  revolves  an  endless  screw,  B.  The  saw- 
dust is  regularly  fed  in  through  the  vertical  pipe  C,  and  falling  upon  the 
screw  is  kept  moving  at  a  uniform  speed  along  the  entire  length  of  the 
heated  retort.  At  the  farther  end  the  vapors  and  gaseous  products  of  the 

*  Ost,  Lehrbuch  der  technische  Chemie,  p.  294. 


PKOCESSES   OF  MANUFACTURE. 


3r  ; 
t>-L 


distillation  escape  through  an  ascending  pipe,  K,  leading  to  the  condenser, 
while  the  powdered  charcoal  drops  through  the  pipe  D  into  water,  where  it 
is  at  once  quenched. 

A  general  view  of  the  products  of  the  distillation  of  wood  and  their  sub- 
sequent treatment  is  given  in  the  accompanying  diagram  taken  from  Post.* 

2.  TREATMENT  AND  PURIFICATION  OF  THE  CRUDE  WOOD-VINEGAR. — 
The  brown  aqueous  solution  poured  off  from  the  tarry  layer  (see "above)  has 
a  strong  empyreumatic  odor,  and  contains,  besides  the  acetic  acid,  methyl 
alcohol,  acetone,  and  homologous  ketones,  allyl  alcohol,  homologues  of  acetic 

FIG.  102. 


acid  (such  as  formic,  propionic,  butyric,  and  valerianic  acids),  methyl  acetate, 
acetate  of  ammonia  and  of  methylamine,  aldehyde,  furfurol,  phenols,  and 
other  empyreumatic  and  tarry  bodies.  It  is  not  used  in  its  crude  condition 
except  in  the  preparation  of  the  crude  pyrolignite  of  iron  (iron-liquor)  or  in 
limited  amount  for  impregnating  wood.  The  first  step  towards  purification 
is  to  separate  the  wood-naphtha  (the  fraction  containing  the  methyl  alcohol 
acetone  and  methyl  acetate)  from  the  wood-vinegar  (crude  acetic  acid),  which 
is  done  by  distillation.  Two  procedures  are  possible  here.  Either  to  neu- 
tralize the  crude  pyroligneous  acid  with  milk  of  lime  and  then  distil  oif  the 
volatile  constituents  only,  using  an  iron  still,  or  to  distil  the  crude  pyro- 
ligneous acid  from  a  copper  still  without  neutralizing  with  lime.  In  the 
former  case,  while  the  wood-naphtha  distils  oif,  the  tarry  impurities  of  the 
crude  pyroligneous  acid  remain  with  the  lime  salt  in  the  still,  and  on  evap- 

*  Post,  Chem.  Technologic,  p.  78. 


852     INDUSTRIES   BASED   UPON   DESTRUCTIVE   DISTILLATION. 


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PROCESSES  OF  MANUFACTURE.  353 

oration  a  dark  mass  is  obtained  known  as  "  brown  acetate  of  lime."  In 
the  latter  case,  after  catching  the  wood-naphtha  distillate,  the  receiver  is 
changed  and  the  crude  acetic  acid  is  also  collected  freed  to  a  considerable 
extent  from  tarry  matter,  so  that  on  neutralizing  with  milk  of  lime  and 
evaporating  the  product  is  a  lighter  salt  known  as  "  gray  acetate  of  lime." 
The  latter  process  is  now  more  generally  in  use.  The  solution  of  the  cal- 
cium acetate  is  evaporated  in  iron  pans ;  the  phenols  and  tarry  products 
which  volatilized  with  the  acetic  acid  separate  largely  as  scum  and  may  be 
skimmed  off,  so  that  the  residue  of  the  evaporation  is  much  purer  than  the 
product  of  the  other  method  mentioned  above. 

If  the  brown  acetate  of  lime  has  been  obtained  and  is  to  be  further 
worked  for  acetic  acid,  it  is  found  necessary  to  roast  it  at  a  temperature  not 
exceeding  250°  C.  so  as  to  drive  off  as  much  of  the  tarry  impurity  as  pos- 
sible without  decomposing  any  of  the  acetate.  If,  on  the  other  hand,  the 
gray  acetate  is  taken,  it  is  distilled  from  copper  retorts  with  concentrated 
aqueous  hydrochloric  acid,  taking  care  to  avoid  an  excess.  The  acetic  acid 
distils  over  between  100°  and  120°  C.,  is  clear  in  color  and  has  only  a 
slight  empyreumatic  odor.  Its  specific  gravity  usually  ranges  from  1.058  to 
1.061,  and  it  contains  about  fifty  per  cent,  of  pure  acetic  acid.  If  some 
water  is  added  with  the  hydrochloric  acid  so  that  the  distilled  acetic  acid  is 
more  dilute  it  tends  to  give  a  purer  product,  as  the  liberated  acetic  acid  can- 
not decompose  any  of  the  calcium  chloride  before  coming  over.  A  good 
proportion  is  said  to  be  one  hundred  parts  of  acetate  of  lime,  ninety  tc 
ninety-five  of  hydrochloric  acid  of  1.160  specific  gravity,  and  twenty-five 
parts  of  water.  The  acetic  acid  so  obtained  has  a  slight  empyreumatic  odor. 
It  may  be  freed  from  this  by  distilling  with  from  two  to  three  per  cent,  of 
potassium  bichromate,  or  by  filtration  through  freshly  ignited  wood  charcoal. 

The  brown  acetate  of  lime  usually  contains  about  sixty-eight  to  sixty- 
nine  per  cent,  of  pure  acetate,  whiie  the  gray  acetate  contains  from  eighty- 
five  to  eighty-six  per  cent,  of  true  acetate. 

In  recent  years  it  has  been  found  practicable  to  prepare  pure  acetic  acid 
from  the  crude  pyroligneous  acid  l>y  making  the  sodium  salt  instead  of  the 
lime  salt.  The  sodium  salt  allows  of  purifying  by  recrystallization,  and 
can  also  be  fused  without  decomposition.  Glacial  acetic  acid  is  generally 
made  by  distilling  the  anhydrous  and  fused  sodium  acetate  with  concentrated 
sulphuric  acid. 

Rohrmann  has  recently  developed  a  process  by  which  it  is  possible  to 
make  ninety  per  cent,  or  even  glacial  acetic  acid  direct  from  the  crude  acetate 
of  lime  in  one  operation.  He*  uses  a  column  still  provided  with  Lunge- 
Rohrmann  plates,  over  which  concentrated  sulphuric  acid  is  made  to  trickle. 
Tins  meets  the  ascending  acetic  vapors  and  dehydrates  them.  They  pass 
over  into  a  condenser,  while  the  empyreumatic  vapors  are  drawn  off  by  a 
warm-air  current  which  connects  with  the  column.  When  hydrochloric 
acid  is  used  to  decompose  the  acetate  the  resulting  acetic  acid  can  be  brought 
to  eighty  per  cent. ;  when  sulphuric  acid  is  used,  one  hundred  per  cent,  acid 
can  be  obtained. 

3.  PURIFICATION  OF  THE  CRUDE  WOOD-SPIRIT. — The  wood-spirit 
forms  the  first  fraction  when  the  crude  pyroligneous  acid  is  distilled,  and 
amounts  to  perhaps  one-sixth  of  the  latter  in  bulk.  It  is  usual  to  collect, 
however,  until  the  hydrometer  reading  of  the  distillate,  which  begins  at 
about  .900,  has  risen  to  1.000  or  a  little  beyond.  This  distillate  forms  a 
greenish-yellow  liquid  of  unpleasant  odor  and  contains  many  impurities 

23 


354      INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

besides  the  acetone  and  methyl  acetate,  the  chief  substances  which  are  pres- 
ent with  the  methyl  alcohol.  Milk  of  lime  is  first  added  and  allowed  to 
stand  with  the  liquid  for  several  hours.  The  mixture  heats  up  quite  dis- 
tinctly as  the  lime  combines  with  any  free  acid  and  begins  to  decompose  the 
methyl  acetate  and  other  ethereal  compounds  of  acetic  acid,  small  quantities 
of  ammonia  often  being  given  off.  It  is  then  distilled  by  connecting  it  with 
a  column  rectifying  apparatus.  (See  p.  220.)  The  distillate  thus  obtained, 
of  about  .816  specific  gravity,  is  colorless  at  first  but  gradually  darkens  in 
color,  and  if  diluted  with  water  becomes  milky  from  separated  oily  hydro- 
carbons and  ketones.  It  is  therefore  diluted  down  with  water  to  about  .935 
specific  gravity  and  allowed  to  stand  until  this  oily  impurity  rises  to  the  top 
in  a  distinct  layer.  The  diluted  spirit  is  again  distilled  over  lime  once  or 
twice  with  a  rectifying  column  and  so  brought  to  ninety-eight  or  ninety-nine 
per  cent,  strength.  The  acetone  impurity,  however,  is  not  removed  by  any 
of  these  rectifications,  as  the  boiling-point  of  acetone  (56.4°  C.)  and  methyl 
alcohol  (55.1°  C.)  do  not  allow  of  their  separation  in  this  way.  To  re- 
move the  acetone  a  number  of  methods  have  been  proposed.  The  methyl 
alcohol  may  be  converted  into  the  solid  chloride  of  calcium  compound,  or 
the  oxalate  of  methyl  and  the  acetone  having  been  removed  by  careful  heat- 
ing, the  methyl  compound  is  decomposed  by  water  or  alkali.  Or  the  methyl 
alcohol  is  distilled  over  chloride  of  lime,  which  reacts  with  the  acetone  to 
form  chloroform.  The  passing  in  of  chlorine  in  order  to  convert  the  acetone 
into  high-boiling  chloracetones,  which  are  then  separated  from  the  methyl 
alcohol  by  distillation,  has  also  been  proposed. 

4.  TREATMENT  OF  THE  WOOD-TAR. — The  tar  which  has  separated  from 
the  crude  pyroligneous  acid  by  settling,  and  that  which  has  risen  and  been 
skimmed  off  in  the  neutralizing  of  the  acid,  are  united  and  submitted  to  dis- 
tillation in  horizontally-placed  iron  retorts,  which  are  set  at  a  slight  inclina- 
tion. At  first  acid-water  comes  over,  then  light  oils,  and  finally  heavy  oils 
until  no  more  will  distil.  The  pitchy  residue  is  run  out  while  hot,  so  that 
it  does  not  adhere  to  the  walls  of  the  retort.  The  relative  amounts  of  the 
several  fractions  from  the  tar  depend  upon  the  nature  of  the  wood  used  in 
the  original  distillation  and  upon  the  way  that  distillation  has  been  carried 
out.  Hard  woods  usually  give  a  tar  which,  according  to  Vincent,  when 
redistilled  yields  as  follows  : 

Aqueous  distillate  (wood-spirit  and  pyroligneous  acid)  .    .  10  to  20  per  cent. 
Lighter  oily  distillate  (specific  gravity  .966  to  .977)    .    .    .  10  to  15    "      " 
Heavy  oily  distillate  (specific  gravity  1.014  to  1.021)  ...  16    "" 

Pitch 50  to  65    "      " 

The  oily  distillates  are  washed  with  weak  soda  to  remove  adhering  acid 
and  then  carefully  rectified,  when  the  oils  coming  over  under  150°  C.  are  col- 
lected for  solvent  and  varnish-making  purposes,  those  between  150°  and  250° 
C.  collected  as  creosote  oils,  and  those  above  250°  C.  used  for  burning  oils. 

The  creosote  oil,  which  is  the  most  valuable  part,  is  thoroughly  agitated 
with  strong  caustic  soda  solution,  the  aqueous  layer  drawn  off,  mixed  with 
sulphuric  acid,  and  allowed  to  stand  for  a  time  at  rest,  when  the  creosote 
oil  separates  out.  This  is  best  driven  off  by  steam  distillation  and  again 
rectified  finally  from  glass  retorts. 

Stockholm  tar,  so  largely  used  in  ship-building,  is  the  product  of  a  rude 
distillation  of  the  resinous  wood  of  the  pine. 

North  Carolina  pine-tar  is  also  the  product  of  a  distillation  of  the  pine. 
The  billets  of  pine-wood  are  piled  in  heaps  like  a  charcoal-burner's  mound, 


PRODUCTS.  355 

though  not  so  large,  covered  in  with  clay  and  turf,  and  lighted  from  the 
top.  The  resin  or  tar  distils  downward  and  runs  off  through  inclined 
troughs  previously  fixed  for  it.  It  is  obvious  that  the  composition  of  both 
the  Stockholm  and  the  North  Carolina  tar  differs  notably  from  that  of 
wood-tar  distilled  in  retorts  from  hard  woods.  This  composition  will  be 
referred  to  later. 

in.   Products. 

1.  PYROLIGNEOUS  ACID  AND  PRODUCTS  THEREFROM. — The  crude  acid 
as  obtained  in  the  distillation  is  a  clear  liquid  of  reddish-brown  color  and 
strong  acid  taste,  with  a  peculiar  penetrating  odor  described  as  empyreu- 
matic,  and  now  known  to  be  due  largely  to  the  furfurol  it  contains.     It 
possesses  a  specific  gravity  of  from  1.018  to  1.030  and  contains  from  four 
to  seven  per  cent,  of  real  acetic  acid.     Pyrolignite  of  iron  (iron  or  black 
liquor)  is  a  solution  of  ferrous  acetate  with  some  ferric  acetate,  prepared  by 
acting  upon  scrap-iron  with  crude  pyroligneous  acid.     It  forms  a  deep- 
black  liquid,  and  is  concentrated  by  boiling  to  1.120  specific  gravity,  when 
it  contains  about  ten  per  cent,  of  iron.     It  is  extensively  used  by  calico-- 
printers.    Brown  and  gray  acetate  of  lime  have  been  already  referred  to. 
Other  technically  important  acetates  are  lead  acetate  (sugar  of  lead),  used  in 
the  preparation  of  the  alum  mordants  and  the  lead  pigments  ;  copper  acetate, 
the  basic  salt  of  which  is  known  as  "  verdigris ;"    aluminum  acetate,  the 
solution  of  which  is  used  in  calico-printing  under  the  name  of  "  red  liquor/' 

Pure  acetic  acid  is  a  colorless  acid  liquid  with  pungent  smell  and  tastei 
It  crystallizes  when  chilled  in  large  transparent  tablets,  melting  at  16.7°  C.J, 
whence  the  name  "glacial  acetic  acid."  Its  specific  gravity  at  15°  C.  is 
1.0553,  and  it  boils  under  normal  pressure  at  119°  C. 

2.  METHYL  ALCOHOL  AND  WOOD-SPIRIT. — As  before  stated,  crude 
tvood-spirit  is  a  complex  liquid  and  contains  many  impurities.     The  per- 
centage of  real  methyl  alcohol  may  rise  to  ninety-five  per  cent.,  but  more 
generally  ranges  from  seventy-five  to  ninety  per  cent.     Some  impure  wood- 
naphthas  go  much  lower,  however,  than  this.      A  large  percentage  of 
acetone  does  not  interfere  with  its  use  as  a  solvent  for  resins  and  for  var- 
nish-making, but  does  interfere  with  its  use  in  the  aniline-color  industry  > 
where  a  very  pure  methyl  alcohol  is  needed  for  the  manufacture  of  dimethyl 
aniline.     The  methods  of  freeing  methyl  alcohol  from  the  two  chief  im{ 
purities,  methyl  acetate  and  acetone,  have  already  been  referred  to.     Pure| 
methyl  alcohol  has  a  purely  spiritous  odor,  a  specific  gravity  of  .7995  at 
15°  C.,  and  boils  at  55.1°  C.     It  is  misbible  in  all  proportions  with  water^ 
ordinary  alcohol,  and  ether. 

3.  ACETONE. — This  substance  is  of  interest  as  always  produced  in  the 
distillation  of   wood,  and  hence  present  in,  the  crude  wood-spirit.     Th$ 
acetates  yield  it  as  the  chief  product  when  submitted  to  dry  distillation,  and 
the  vapors  of  acetic  acid  distilled  over  porous  baryta  at  a  temperature  of 
from  350°  C.  to  400°  C.,  it  has  been  found  by  Dr.  Squibb,  will  also  readily 
yield  acetone.     One  hundred  kilos,  of  forty  per  cent,  acid  will  give  from 
twelve  to  thirteen  kilos,  of  acetone.     At  present  it  is  made  on  a  large  scale 
by  distilling  the  gray  acetate  of  lime  in  iron  stills  provided  with  mechanical 
agitation  at  a  temperature  of  about  290°  C.     When  purified,  it  is  a  color-^ 
less  liquid  of  peculiar  ethereal  odor  and  burning  taste,  and,  like  methyl 
alcohol,  is  miscible  in  all  proportions  with  ether,  alcohol,  and  water.     It  is 
an  excellent  solvent  for  resins,  gums,  camphor,  fats,  and  pyroxylin,  or  gun- 


356     INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 


cotton.  It  does  not  form  a  compound  with  dry  calcium  chloride,  and  can 
thus  he  separated  from  methyl  alcohol  when  in  admixture  with  this  latter. 
Chlorine  and  iodine  in  the  presence  of  an  alkali  react  with  acetone  to  Ibrm 
chloroform  and  iodoform. 

4.  CREOSOTE. — Wood-tar  creosote  is  a  strongly  refracting  liquid,  which 
is  colorless  when  freshly  distilled  but  gradually  acquires  a  yellow  or  brown 
color.     It  has  a  smoky  aromatic  odor,  which  is  very  persistent  and  is  quite 
distinct  from  that  of  carbolic;  acid.     It  has  a  specific  gravity  ranging  from 
1.030  to  1.080,  and  boils  between  205°  and  220°  C.     It  is  a  powerful 
antiseptic,  and  is  largely  used  to  preserve  meats,  etc.     It  differs  from  coal- 
tar  creosote  in  containing  relatively  little  common  phenol  (carbolic  acid) 
and  relatively  large  amounts  of  higher  phenols,  such  as  phlorol,  C8H9.OH, 
guaiacol,  C7H7O.OH,  and  creosol,  C8H9O.OH. 

5.  PARAFFINE. — This  mixture  of  solid  hydrocarbons,  as  already  said, 
occurs  in  the  higher  boiling  distillate  gotten  from  wood.     It  is  of  interest 
to  recall  that  paraffine  was  first  discovered  by  Reichenbach  in  beech-wood 
tar.     At  present,  however,  the  extraction  of  paraffine  from  wood-tar  is  not 
to  be  thought  of  because  of  the  cheapness  of  its  production  from  petroleum 
and  bituminous  shales.     It  has  been  already  described  under  the  chapter  on 
Petroleum.     (Seep.  31.) 

6.  CHARCOAL. — We  have  already  shown  in  the  table  of  results  of  slow 
and  rapid  distillation  of  wood  (see  p.  350)  that  the  relative  amount  of  char- 
coal depends  upon  the  manner  of  heating,  being  larger  with  gradual  appli- 
cation of  heat  and  smaller  with  rapid  heating.     The  properties  and  chemical 
composition  of  the  charcoal  are  similarly  dependent  upon  the  tempeiature 
to  which  the  wood  is  heated.     Wood  is  stated  to  become  brown  at  220°  C., 
at  280°  C.  it  becomes  a  deep  brownish-black  and  begins  to  be  friable,  and  at 
310°  C.  forms  an  easily  friable  black  mass  taking  fire  easily.     That  prepared 
at  higher  temperatures  is  harder  and  less  readily  ignited,  and  it  eventually 
becomes  graphitic  and  rings  with  a  metallic  sound  when  struck.     The  accom- 
panying table  from  Yiolette  shows  the  gradual  change  in  the  composition 
of  charcoal  prepared  at  different  temperatures  from  the  same  kind  of  wood 
(buckthorn) : 


Heated  to 

Carbon, 
per  cent. 

Hydrogen, 
per  cent. 

Oxygen,  nitro- 
gen, and  loss. 

Ash, 
per  cent. 

Dry  wood  

150°  C. 

47.51 

6.12 

46.29 

008 

Charred  wood 

260°  C 

67  85 

504 

26  49 

0  56 

lifd  charcoal  .           .   . 

280°  0 

72  64 

4  70 

22.10 

0.57 

Brown  charcoal    .... 

820°  O. 

73.57 

4.88 

21.09 

0.52 

Dull  black  charcoal  .    .    . 

340°  C. 

75.20 

4.41 

19.96 

0.48 

Lustrous  black  charcoal  . 

432°  C. 

81.64 

1.96 

15.25 

1.16 

Extreme  white  heat     .    . 

1500°  C. 

96.52 

0.62 

0.94 

1.95 

IV.  Analytical  Tests  and  Methods. 

1.  ASSAY  OF  PYROLIGNEOUS  ACID  AND  CRUDE  ACETATES. — The 
crude  pyroligneous  acid,  as  before  stated,  contains  from  four  to  seven  per 
cent,  of  real  acetic  acid.  Its  strength  may  be  ascertained  by  titration  with 
standard  alkali,  using  phenol-phthalein  as  an  indicator.  If  the  liquid  is 
too  dark  to  allow  of  the  end  reaction  being  readily  seen,  it  can  be  diluted 
sufficiently,  as  the  reaction  will  still  be  sufficiently  delicate.  In  the  absence 


ANALYTICAL  TESTS  AND  METHODS.  357 

of  sulphates  in  the  sample,  the  acetic  acid  can  be  determined  by  adding 
excess  of  pure  precipitated  barium  carbonate  to  the  solution,  filtering,  and 
determining  the  barium  in  the  filtrate  by  the  aid  of  sulphuric  acid. 

As  the  pyroligneous  acid  is  largely  converted  into  calcium  acetate  in  the 
process  of  purifying,  the  analysis  of  the  brown  or  gray  acetate  of  lime  as  a 
common  commercial  product  becomes  of  some  importance.  This  commercial 
acetate  may  contain  from  sixty-five  to  eighty  per  cent,  of  true  acetate  of  lime, 
with  carbonate  of  lime,  so-called  "  tar-lime,"  and  empyreumatic  matter  as 
chief  impurities.  The  acetic  acid  determination  may  be  made  by  different 
methods,  but  the  most  accurate  according  to  the  experience  of  the  author  is 
the  distillation  method,  as  suggested  by  Stillwell  and  Gladding.  One  gramme 
of  the  sample  of  acetate  of  lime  is  placed  in  a  small  distillation  bulb  or  flask 
with  a  long  neck,  a  little  distilled  water  added,  and  then  a  solution  of  five 
grammes  of  glacial  phosphoric  acid  dissolved  in  ten  cubic  centimetres  of 
water.  The  flask  is  then  heated  to  distil  off  the  acetic  acid,  care  being  taken 
to  avoid  spurting  and  mechanical  carrying  over  of  any  of  the  phosphoric 
acid.  When  the  contents  have  nearly  gone  to  dryness,  some  twenty-five 
cubic  centimetres  of  distilled  water  are  introduced  and  the  distillation  re- 
peated. If  this  is  done  some  three  or  four  times,  the  distillate  will  be  found 
to  be  free  from  acid  reaction.  The  combined  distillate  is  then  brought  to 
definite  volume  and  titrated  with  decinormal  soda  solution,  using  phenol- 
phthalein  as  indicator. 

2.  DETERMINATION  OP  METHYL  ALCOHOL  IN  COMMERCIAL  WOOD- 
SPIRIT. — But  one  method,  and  that  not  capable  of  the  most  accurate  working, 
is  at  present  available.     Five  cubic  centimetres  of  the  sample  of  wood-spirit 
are  allowed  to  drop  slowly  upon  fifteen  grammes  of  phosphorous  di-iodide 
placed  in  a  small  flask  of  some  thirty  cubic  centimetres  capacity.    This  is  con- 
nected with  an  inverted  condenser  and  cooled  externally  while  the  reaction 
takes  place.     Five  cubic  centimetres  of  a  solution  of  one  part  iodine  in  one 
part  of  hydrogen  iodide  of  1.7  specific  gravity  is  then  added  and  the  mixture 
gently  digested  for  a  quarter  of  an  hour,  when  the  condenser  having  been 
turned  downward  the  iodide  of  methyl  formed  is  distilled  off.     It  is  col- 
lected in  a  graduated  tube  divided  into  one-tenth  cubic  centimetres,  washed 
with  some  fifteen  cubic  centimetres  of  water  with  vigorous  agitation,  allowed  to 
settle,  and  the  volume  read  off.    Five  cubic  centimetres  of  pure  and  perfectly 
dry  methyl  alcohol  should  give  7.45  cubic  centimetres  of  iodide  of  methyl. 

3.  DETERMINATION  OF  THE  ACETONE  IN  COMMERCIAL  WOOD-SPIRIT. 
— This  may  be  done  by  either  the  Kraemer  and  Grodzki  gravimetric  method 
or  the  Messinger  volumetric  method,  both  of  which  depend  upon  its  quanti- 
tative conversion  in  the  presence  of  iodine  and  caustic  alkali  into  iodoform. 
In  the  former  case,  one  cubic  centimetre  of  the  sample  of  wood-spirit  is 
mixed  with  ten  cubic  centimetres  of  a  double  normal  solution  of  caustic 
soda  (eighty  grammes  to  the  litre),  and  to  the  mixture,  after  thorough  agita- 
tion, is  added  five  cubic  centimetres  of  a  solution  containing  two  hundred 
and  fifty-four  grammes  of  iodine  and  three  hundred  and  thirty-two  grammes 
of  potassium  iodide  to  the  litre.     The  iodoform  which  separates  pn  agitation 
is  dissolved  by  the  addition  of  ten  cubic  centimetres  of  ether  free  from 
alcohol.     An  aliquot  portion  of  the  ethereal  layer  is  then  pipetted  off  into 
a  tared  watch-crystal,  and  the  iodoform  remaining  after  evaporation    is 
weighed.     Three  hundred  and  ninety-four  parts  of  iodoform  correspond  to 
fifty-eight  parts  of  acetone.     More  accurate  is  the  Messinger  volumetric 
process.     In  this,  twenty  cubic  centimetres  (or  thirty  cubic  centimetres  in 


358     INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

Samples  rich  in  acetone)  of  normal  potash  solution  and  one  or  two  cubic 
centimetres  of  the  wood-spirit  in  question  are  shaken  together  in  a  stop- 
pered 250-cubic-centimetre  flask  and  a  known  quantity  (twenty  or  thirty 
cubic  centimetres)  of  a  one-fifth  normal  iodine  solution  added.  The  mixture 
is  shaken  until  the  supernatant  liquid  clears  perfectly  on  momentary  stand- 
ing, hydrochloric  acid  of  1.025  specific  gravity  is  added  in  amount  equal  to 
the  potash  solution  before  used,  and  excess  of  decinormal  sodium  thio- 
sulphate  run  in.  Starch  paste  is  then  added,  and  the  excess  of  sodium 
thiosulphate  titrated  with  one-fifth  normal  iodine  solution.  If  r  be  the 
volume  in  cubic  centimetres  of  the  iodine  solution  required  to  combine  with 
the  acetone,  and  n  the  volume  in  cubic  centimetres  of  the  methyl  alcohol 
taken,  then  the  quantity  of  acetone  by  weight  in  one  hundred  cubic  centime- 

f  4.1.            i    •           i  *     r  X  -1^3345 
tres  of  the  sample  is  equal  to 

<•  4.  QUALITATIVE  TESTS  FOR  WOOD-TAR  CREOSOTE. — Allen  *  enumer- 
ates the  following  tests  as  characteristic  of  wood-tar  creosote  or  as  sufficing 
to  distinguish  it  from  coal-tar  creosote  :  (1)  An  alcoholic  solution  of  wood- 
creosote  should  not  give  any  coloration  whatever  (neither  blue  nor  reddish) 
with  baryta-water;  (2)  wood-tar  creosote  is  practically  insoluble  in  strong 
ammonia  ;  (3)  wood-tar  creosote  is  also  distinguished  from  the  coal-tar  acids 
by  its  reaction  with  an  ethereal  solution  of  nitrocellulose.  Shaken  with 
half  its  measure  of  collodion  solution  carbolic  acid  coagulates  the  gun-cotton 
to  a  transparent  jelly.  Creosote  does  not  precipitate  the  nitrocellulose  from 
collodion  but  mixes  perfectly  with  the  ethereal  solution  ;  (4)  wood-tar  creo- 
sote is  sharply  distinguished  from  the  coal-tar  acids  by  its  insolubility  in 
absolute  glycerine  (specific  gravity  1.26),  whether  one,  two,  or  three  times 
its  volume  of  that  liquid  be  employed. 

B.  DESTRUCTIVE  DISTILLATION  OF  COAL. 

]:  I.  Raw  Materials. 

Probably  the  most  important  industry  involving  the  destructive  distilla- 
tion of  coal  is  the  manufacture  of  illuminating  gas.  The  classes  of  coals  em- 
-ployed  for  the  purpose  are  confined  to  those  varieties  which  are  bituminous 
in  their  nature,  yielding  when  distilled  volatile  hydrocarbons  in  varying  quan- 
tity. The  uncombined  or  "  fixed  carbon,"  with  the  mineral  constituents 
originally  present  in  the  coal,  remaining  after  the  distillation  comprise  coke. 

Bituminous  Coals  have  the  property,  not  possessed  by  the  anthracites, 
of  softening  and  apparently  fusing  when  subjected  to  a  temperature  below 
that  at  which  combustion  would  take  place.  This  fusion  indicates  the  com- 
mencement of  destructive  distillation,  when  both  solid,  liquid,  and  gaseous 
carbon  compounds  are  formed.  Bituminous  coal  is  essentially  a  coking  coal, 
and  as  such  is,  to  a  very  great  extent,  employed  in  the  coking  regions  of 
:Western  Pennsylvania.  It  is  black  or  grayish-black  in  color,  of  a  resinous 
lustre,  and  somewhat  friable,  being  easily  broken  into  cubical  fragments  of 
more  or  less  regularity ;  upon  ignition  it  burns  with  a  yellow  flame.  When 
it  is  heated  to  bright  redness  in  retorts  or  ovens,  free  from  the  access  of  air, 
the  volatile  matter,  before  mentioned,  carbon  compounds  of  hydrogen  and 
of  oxygen,  with  water,  pass  off.  Coals  having  a  large  percentage  of  hydro- 
gen will  yield  more  volatile  substances  at  the  temperature  of  distillation 

i  *  Commercial  Organic  Analysis,  2d  ed.,  vol.  ii.  p.  568. 


RAW  MATERIALS. 


359 


and  less  carbonaceous  residue  than  others  which  may  contain  less  hydrogen 
and  more  carbon, — approaching  anthracite  in  composition. 

Coking  and  Non-coking  Coals  are  quite  similar  in  chemical  composition ; 
the  coking  varieties  contain  less  volatile  matter,  however,  than  the  non- 
coking  ;  the  latter  do  not  possess  the  property  of  fusing  to  a  compact 
"  coky"  mass,  but  retain  their  original  form,  and  yield  a  coke  which  has  no 
commercial  value  unless  it  is  obtained  from  large  pieces  of  the  coal. 

Oannel  Coal  is  much  more  compact  than  gas  or  coking  coals,  duller  in 
appearance,  possessing  a  grayish-black  to  brown  color,  and  burning  with  a 
clean  candle-like  flame.  It  does  not  soil  the  hands,  and  is  not  readily  frac- 
tured. It  is  capable  of  taking  a  high  polish,  and  can  be  cut  or  turned  into 
articles  for  use  or  ornamentation.  Cannel  coal  occurs  in  large  quantities 
in  West  Virginia,  and  near  Glasgow,  Scotland,  in  Lancashire,  England,  and 
at  other  localities.  Destructively  distilled,  it  yields  a  larger  amount  of 
volatile  matter  and  ash,  with  much  less  coke,  than  the  bituminous  coals. 

Brown  Coal,  or  Lignite,  appears  to  occupy  an  intermediate  position  be- 
tween the  bituminous  coals  and  wood.  It  retains  the  ligneous  structure  of 
the  material  from  which  it  is  formed, — hence  the  name  Lignite.  The  vege- 
table remains  in  a  great  many  cases  are  quite  distinct.  The  color  varies  from 
yellowish-brown  in  the  earthy,  to  black  in  the  more  compact,  coal-like 
varieties.  The  percentage  of  carbon  contained  is  low,  fifty  to  eighty  per 
cent.,  though  rarely  exceeding  seventy  per  cent.,  while  the  hydrogen  is  from 
4  to  6.85  per  cent.  Oxygen  and  nitrogen  are  present  in  variable  quan- 
tities from  7.59  to  36.1  per  cent.  The  ash  in  good  qualities  is  low,  in 
earthy  specimens  is  high,  in  many  cases  exceeding  fifty  per  cent.  Lignite 
does  not  yield  coke.  Aside  from  being  utilized  as  fuel  in  the  several  local- 
ities where  it  is  found,  for  both  domestic  and  industrial  purposes,  it  has 
been  distilled  for  volatile  constituents  in  Saxony. 

Peat,  or  Turf,  occurring  in  large  areas  in  Ireland  and  in  some  parts  of 
Europe,  consists  of  the  decayed  remains  of  certain  forms  of  plants.  It  has 
been,  according  to  Mills,  destructively  distilled  for  tarry  products,  the  in- 
dustry, however,  being  no  longer  profitable. 

The  following  tables,  taken  from  the  Reports  of  the  Second  Geological 
Survey  of  Pennsylvania,  show  the  analyses  of  some  of  the  more  important 
varieties  of  American  gas  coals,  coking  coals,  and  non-coking,  or  block 
coals. 

/.   Gas  Coals. 


WESTMORELAND  COAL  COMPANY. 

PENNSYLVANIA  GAS  COAL  COMPANY. 

South  Side 
Mine. 

Foster 
Mine. 

Larrimer, 
No.  2. 

Irwin, 
No.  1. 

Irwin, 
No.  2. 

Sewickley. 

Water  at  225°  .  . 
Volatile  matter  . 
Fixed  carbon.  . 
Sulphur  .... 
Ash 

1.410 
37.655 
54.439 
0.636 
5.860 

1.310 
37.100 
55.004 
0.636 
5.950 

1.560 
39.185 
54.352 
0.643 
4.260 

1.780 
35.360 
59.290 
0.680 
2.890 

1.280 
38.105 
54.383 
0.792 
5.440 

1.490 
37.153 
58.193 
0.658 
2.506 

Total  .... 

100.000 

100.000 

100.000 

100.000 

100.000 

100.000 

Coke,  per  cent.  . 
Fuel  ratio  .  .  . 

60.935 
1:1.47 
McCreath. 

61.590 
1:1.48 
McCreath. 

59.255 
1:1.38 
McCreath. 

62.860 
1  :  1.67 
McCreath. 

60.615 
1  :  1.42 
McCreath. 

61.357 
1:1.56 
McCreath. 

360     INDUSTRIES  BASED  UPON   DESTRUCTIVE   DISTILLATION. 


//.    Coking  Coals. 


Oonnells- 
ville, 
Frick  &  Co. 

Bennington, 
Cambria 
In.n 
Company. 

Broad  Top, 
Baruet. 

Broad  Top, 
Kelley. 

Cumber- 
land. 

Huntingdon 
County, 
Alloway 
Colliery. 

Moisture  .... 
Volatile  matter. 
Fixed  carbon  . 
Sulphur  .... 
Ash 

1.260 
30.107 
59.616 
0.784 
8233 

1.400 
27._25 
61.843 
2.602 
6930 

1600 
7465 
1.85 
7  50 

19.68 
71.12 
1.70 
750 

1.10 
15.30 
73.28 
1.23 
908 

0.2-r'0 
14.510 
77.042 
1338 
6860 

Total.  .  .  . 

100.000 

100.000 

100.00 

100.00 

lOd.OO 

100.000 

Coke,  per  cent.  . 
Fuel  ratio  .  .  . 

68.63 
1:1.98 
Mcdeath. 

71.37. 
1  :  2.27 
McCieath. 

81.00 
T.T.Morrell. 

71.00 
T.T.Morrell. 

83.59 
1  :  4.78 
McCreath. 

85.24 
1  :  5.30 
McCreath. 

///.    Non-coking  Coals  (Block  Coal). 


Mercer 
County,  Pa., 
Sharon  Coal. 

Younpstown, 
Ohio. 

Mercer 
County,  Pa. 

Straitsville, 
Ohio. 

Brazil,  Ind. 

Moisture     .... 
Volatile  matter  .    . 
Fixed  carbon     .    . 
Sulphur  

3.79 
35.30 
53.875 
0  675 

3.60 
32.58 
62.66 
(0  8-Vl 

3.80 
25.49 
68.03 
1  04 

36.50 
55.60 
0.96 

io!  15 
57.20 
0.75 

Ash      

6.36 

1.16 

1.70 

6.94 

1.90 

Total  .... 

100.000 

100.00 

100.06 

100.00 

10000 

Coke,  per  cent.  .    . 

60.91 
McCreath. 

Wormley. 

Jno.  Fulton. 

61  00 
Wormley. 

58.00 
Prof.  Cox. 

Effects  of  High  or  Low  Temperature  in  the  Distillation  of  Coal. — Coal 
when  distilled  at  a  low  temperature  yields  products  of  a  very  different 
nature  from  those  obtained  if  the  temperature  employed  had  been  high. 
On  this  subject  Professor  Edmund  T.  Mills,  of  Glasgow,  in  his  little  man- 
ual on  "  Destructive  Distillation"  (3d  ed.,  p.  9),  states  that  "at  a  very  high 
temperature  the  products  from  coal  and  shales  are  carbon  and  carbonized 
gases  of  low  illuminating  power,  with  but  little  liquid  distillate ;  at  a  low 
temperature  there  is  much  liquid  product  and  gas  of  high  illuminating 
power.  The  greatest  amount  of  liquid  product  of  low  boiling-point  is  found 
in  American  and  Russian  petroleums,  which  have  probably  been  produced 
by  the  long-continued  application  of  a  very  gentle  natural  heat. 

"  When  coal  is  slowly  heated  (as  must  be  to  a  great  extent  the  case  when 
it  is  broken  fine,  or  when  a  large  retort  is  used),  its  oxygen  is  chiefly  con- 
verted into  water ;  when  rapidly  heated,  the  oxygen  is  expelled  as  carbonic 
oxides." 

To  show  the  verification  of  these  principles  in  practice,  the  results  of 
high  and  low  temperature  d:st!llation  upon  three  different  coals  may  be 
quoted  from  the  same  authority  : 


"1 


lo 


. 


,        1 

DI  AC 

Showing  the  most  important  of  the  products  derived  from 

manufact 


The  direct  products  which  can  be  separated  as  they  come  over  from  the  still,  by  filtra- 
tion or  other  simple  processes,  are  marked  thus,  | 1       Those  substances  which  are 

prepared  by  further  chemical  treatment  are  marked 


E 


1 

COAL  GAS'. 

GAS-LIQUOR. 

C 

Liquid 
Ammonia 

Sulphate 
of 
Ammonia. 

Chloride 
of 
Ammonia. 

Carbon- 
ate <  »f 
Ammonia. 

Oils  lighter  than  water  or 
Crude  Naphtha. 


Oils  heavier  than  v 
or  tar,  comm  « 


BENZOL. 


TOLUOL. 


Nitrb- 
Benzvl. 


XYLOL. 


Wtro- 
ToluoL 


ANILINE. 


TOLUI- 

DINE. 


CUMOL. 


Nitro- 
Xylol. 


PYRIDINE. 


CARBOLIC 
ACID. 


CRESYLIC 
ACID. 


CARBOLIC 
ACID. 


CRESYLIt 

ACID. 


Picric 
Acid. 

Aurine. 

Nitro- 
Cumol. 


XYLIDINE. 


CUMIDINE 


For  the  manufacture  of  pure  carbolic, 
cresylic,  and  other  tar  acids,  further  and 
elaborate  treatment  is  required. 


Ewcastle  Coal  when  carbonized  by  the  usual  method  for  the 
of  coke. 


The  direct  products  of  the  dead  oils  are  arranged  as  nearly  as  possible  according  to 
their  respective  volatilities;  and  to  the  order-  in  which  they  come  over  from  the  still. 


1 

1  otherwise  dead  oil                                                                    v,+., 
I  .lied  Creosote.                                                                           PitCH. 

~  GREEN  OILS,  distilling  from  550°  to  730°  P    *: 

Quinoline 
NAPHTHA       Series,—        Phenan-       rOPKn~i        ANTHRA- 
LENE.         e.g.,  Cryp-        threne,        ^arbazoi.         CFNE 
tidine. 

Acridine.       Pyrene        Chrysene.      Bln"Sie." 

Nitro-                                Phenan-                               AV,+V.«» 
Naphtha-                               threnc 
lene                                Quinone.                            QU1DC 

Pyrene         Chryso- 
Qyindne.       Quinone. 

Anthra- 
Naphthyl-                           Diphenic                             quinone 
amine.                                  Acid.                               Sulphonic 
Acid 

p     ' 

1                                          1 

I     APH- 
I     HOU 

PHTHALIC                                               ALIZA 
ACID.                                                   RINE. 

PURPU- 

RINE. 

RAW  MATERIALS. 


361 


Yield  of  Gas,  Oil,  etc.,  from  Shales  and  Coals  at  High  and  Low  Heats. 


GOOD  SHALES. 

BOGHEAD  COAL. 

GAS  COAL. 

High  heats. 

Low  heats. 

High  heats. 

Low  beats. 

High  heats. 

Low  heats. 

«  .    f  Gas  
zz  o)    1  Ammonia-water  .  . 
tag  \  Tar  or  oil    
"c  a       Sulphur    
>  *    [  Water  at  212°  .... 

(  Fixed  carbon     .  . 
Coke  \  Sulphur 

13.65 
3.65 
11.04 
099 

2.82 

2.54 
6.47 
17.65 

~  26.66 
10.81 

62.53 

3732 
2.43 
20.65 
018 
0.80 

~~  61.38 
9.01 
0.06   - 
29.55 

4.83 
3.23 
50.29 

20.49 
3.09 
17.08 
0.29 
4.15 

~~  45.10 
45.00 
0.34 
9.56 

6.49 

7.24 
26.45 

40.18 
49.93 

'9.89 

32.15 
4.16 
1.05 
62.64 

58.35 
1240 

29.26 

(  Ash          

Coke  (dry)  per  ton  of  shale 
or  coal  

67.85 

73.34 

38.62 

41.65 

54.90 

59.82 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

1,520  Ibs. 

LI 

1,642.2  Ibs. 
18 

865  Ibs. 
t! 

934  Ibs. 
24 

1,230  Ibs. 
1.5 

1,340  Ibs. 
96 

Specific  gravity  of  shale  or 
coal 

NOTE.— The  low  heat  results  were  gotten  by  distilling  the  sample  in 
furnace. 


two -inch  iron  tube  in  a  gas- 


Lunge  (Coal-Tar  and  Ammonia,  2d  ed.,  p.  17)  states  that  "The  quan- 
tity, and  to  a  much  greater  extent  the  quality,  of  the  tar  are  influenced  by 
the  temperature  at  which  the  decomposition  of  the  case  is  carried  on.  Low 
temperatures,  with  nine  thousand  cubic  feet  of  gas  per  ton  of  coal,  will 
yield,  with  some  coals,  sixteen  gallons  of  tar ;  whilst  at  high  temperatures 
the  yield  will  be  but  nine  gallons,  with  about  eleven  thousand  cubic  feet  of 
gas,  from  the  same  coal."*  If  the  temperature  being  a  comparatively  low 
one,  mostly  such  hydrocarbons  are  formed  as  belong  to  a  paraffin  (methane) 
series,  having  the  general  formula  CnH2n  +  2,  along  with  the  olefjns,  CnH2n. 
The  lower  members  of  this  series  are  liquid,  and,  furnished  in  the  pure 
state,  are  lighting  and  lubricating  oils  ;  the  higher  ones  are  solid  and  form 
commercial  paraffine.  They  are  always  accompanied  by  oxygenized  deriva- 
tives of  the  benzene  series  (phenols) ;  but  of  these  the  more  complicated 
ones  predominate,  in  some  of  which  methyl  occurs  in  the  benzene  nucleus,  in 
others  replacing  the  hydrogen  of  hydroxyl, — e.g.,  cresol,  C6H4(CH3)(OH) ; 
guaiacol,  C6H4(OH)(OCH3) ;  creosol,  C6H3(CH3)(OH)(OCH3),  etc.  Liquid 
products  prevail ;  and  among  the  watery  ones  acetic  acid  (which  is  again 
a  compound  of  the  fatty  series)  is  paramount.  Of  course  also  permanent 
gases  are  always  given  off,  though  in  comparatively  small  quantity. 

If,  on  the  other  hand,  the  coal  has  been  decomposed  at  a  very  high 
temperature,  the  molecules  are  grouped  quite  differently.  Whilst  the 
olefins  and  members  of  the  acetylene  series  still  occur  more  or  less,  the 
hydrocarbons  of  the  paraffin  series  disappear  almost  entirely ;  and  from 
them  are  formed  on  the  one  hand  compounds  much  richer  in  carbon,  on  the 
other  hand  more  hydrogenized  bodies.  The  latter  always  occur  in  the  gas- 
eous state  ;  hence  the  gas  so  produced  contains  methane,  or  marsh-gas,  CH4, 
and  free  from  hydrogen  as  principal  constituents,  and  is  very  much  increased 
in  quantity.  The  carbon  thus  set  free  is  partly  deposited  in  the  retorts 
themselves,  and  then  occurs  in  a  very  compact  graph itoidal  form ;  another 

*  Davis,  Journ.  See.  Chem.  Ind.,  1886,  p.  5. 


362     INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

portion  of  the  free  carbon  occurs  in  a  state  of  extremely  fine  division  in 
the  tar,  and  forms  a  constituent  of  the  pitch  or  coke  remaining  behind  from 
tar-distilling ;  another  portion  contributes  to  the  formation  of  compounds 
richer  in  carbon,  belonging  to  the  "  aromatic"  series,  all  of  which  are  de- 
rived from  benzene,  C6H6.  At  the  same  time  the  action  of  heat  effects 
further  molecular  "  condensations/7  usually  with  separation  of  hydrogen, 
by  which  process  compounds  of  a  higher  molecular  weight  are  formed,  as 
naphthalene,  anthracene,  phenanthrene,  chrysene,  etc.  The  never  absent 
oxygen  must  also  in  this  case  cause  the  formation  of  phenols ;  but  here 
phenol  proper,  or  carbolic  acid,  C6H6(OH),  predominates,  whilst  cresol  and 
the  other  homologues  are  diminished  in  quantity,  and  the  dioxy-benzenes, 
as  well  as  their  methylated  derivatives,  disappear  altogether.  The  above 
will  be  better  illustrated  by  the  statement  (from  Stohmann-KerPs  "  Chemie," 
3d  ed.,  vi.  p.  1162)  that  Zwickau  glance  coal  yielded  the  following  quite 
different  products,  according  to  whether  it  was  put  into  a  cold  retort  and 
gradually  brought  to  a  red  heat  (a),  or  distilled  quickly  from  a  very  hot 
retort  (6) : 

a.  b. 

Coke .    60.0  50.0 

Water 10.7  7.7 

Tar. 12.0  10.0 

Gas  and  loss 17.1  32.1 

The  tar  from  (a)  consisted  of  photogen,  paraffine  oil,  lubricating  oil, 
paraffine,  and  creosote ;  that  from  (6),  of  benzene,  toluene,  naphthalene,  an- 
thracene (together  with  heavy  oils  corresponding  to  the  paraffine  and  lubri- 
cating oil),  and  much  creosote. 

The  annexed  diagram,  constructed  by  S.  B.  Boulton,  and  published  in 
the  Society  of  Chem.  Ind.  Journal,  1885,  p.  471,  represents  the  whole  pro- 
cess of  the  destructive  distillation  of  coal,  including  the  subsequent  treat- 
ment of  the  main  fractions,  and  exhibits  in  their  proper  order  the  various 
products  obtained  therefrom. 

n.  Processes  of  Treatment. 

1.  GAS-RETORT  DISTILLATIONS  OF  COAL. — The  distillation  of  coal  as 
carried  out  in  retorts  differs  from  distillations  of  other  substances  mainly  in 
the  apparatus  employed  and  in  the  nature  of  the  substances  to  be  recovered. 
For  gas  purposes,  retorts,  wherein  the  decomposition  of  the  coal  used  takes 
place,  are  made  use  of,  which  were  originally  constructed  of  cast  iron,  about 
one  inch  in  thickness,  twelve  to  fifteen  inches  in  width,  and  about  seven  feet 
in  length,  closed  at  the  rear  end,  and  provided  at  the  front  or  mouth  with 
a  heavy  shoulder  or  rim  supplied  with  studs  to  which  is  attached  a  cast-iron 
extension,  technically  termed  the  "  neck,"  which  carries  on  its  upper  side  a 
flange  to  which  is  secured  upright  pipes  serving  to  lead  the  gases  generated 
away  from  the  retort.  The  front  of  the  neck  is  provided  with  a  screw- 
clamp  to  retain  the  lid  or  cap  of  the  retort  in  position.  Iron  retorts  are 
destroyed  with  great  rapidity ;  the  destruction  being  caused  by  the  heat  of 
combustion  of  the  fuel  used,  the  sulphur  in  the  gas  coal  (an  impurity  always 
present  in  more  or  less  quantity),  which  acts,  forming  sulphide  of  iron,  and 
the  carbon,  which,  as  a  carbide  of  iron,  graphitic  in  appearance,  forms  layers 
within  the  retort  from  one  to  two  inches  in  thickness.  The  oxygen  of  the 
air  also  has  a  very  deleterious  influence,  especially  upon  retorts  when  heated 
to  redness. 


PROCESSES  OF  TREATMENT.  363 

In  later  years  fire-clay  retorts  have  been  substituted  for  those  made  of 
cast  iron,  for  the  reason  that  they  are  more  durable.  These  retorts  are  made 
of  a  mixture  of  clay  and  sand,  and  are  furnished  to  the  gas-works  in  several 
shapes,  the  semi-cylindrical  being  the  one  most  generally  employed.  The 
sizes  vary,  six  to  nine  feet  in  length,  fifteen  to  twenty  inches  in  width,  and 
from  ten  to  fifteen  inches  in  height  being  the  average,  and  take  a  charge 
of  one  hundred  and  fifty  to  two  hundred  pounds  of  coal.  Hetorts  have 
been  made  up  to  nineteen  feet  in  length,  being  charged  from  both  ends. 

The  retorts,  varying  in  number  from  five  to  seven,  or  even  nine  and  more, 
are  mounted  in  brick  furnaces  of  special  construction,  in  such  a  manner  that 
the  gases  of  combustion  of  the  coal  will  pass  around  and  over  the  retorts 
and  out  through  a  main  flue  leading  to  the  chimney.  The  fuel  employed 
can  be  either  coal,  coke,  or  a  mixture  of  both.  Gas  as  a  means  of  firing 
has  been  used  for  the  purpose,  the  method  being  based  upon  the  well-known 
regenerative  system  of  Sir  William  Siemens. 

The  retorts  are  charged  by  hand,  care  being  taken  to  evenly  distribute 
the  coal  over  the  sole,  or  bottom,  and  to  close  it  quickly.  Various  attempts 
have  been  made  to  perform  this  laborious  work  with  mechanical  means,  but 
at  present  no  entirely  satisfactory  substitute  has  been  found. 

The  products  of  distillation  pass  from  the  retorts  proper  through  the 
neck,  and  upward  through  cast-iron  stand-pipes,  which  are  provided  with 
goose-neck  outlets,  dipping  below  the  surface  of  water  in  what  is  termed  the 
hydraulic  main. 

It  is  in  this  part  of  the  process  that  the  main  bulk  of  the  tar  is  ob- 
tained, together  with  the  ammonia-liquor.  The  hydraulic  main  is  provided 
with  an  overflow-pipe  through  which  all  the  tarry  matters  pass.  This 
overflow-pipe  leads  to  the  tar- well,  wherein  the  liquid  products  collect. 

The  gas  having  been  freed  from  the  tarry  matters,  etc.,  contained,  passes 
from  the  hydraulic  main  with  a  considerably  elevated  temperature,  carrying 
in  a  vaporized  state  hydrocarbons  that  would  separate  as  its  temperature  is 
lowered.  It  is  necessarily  very  important  to  remove  these  volatile  and  con- 
densable products,  which  is  effected  by  causing  the  gas  to  pass  through  a 
series  of  pipes,  which  reduces  its  temperature  very  close  to  that  of  the  atmos- 
phere. The  older  form  of  condenser  was  a  series  of  pipes  completely  cov- 
ered with  water,  similar  to  the  worms  as  at  present  employed  in  connection 
with  spirit  and  other  distillations.  This  arrangement  was  replaced,  however, 
by  the  forms  now  universally  employed,  and  known  as  the  atmospheric 
condensers,  consisting  of  vertical  pipes  connected  in  pairs  near  the  top  by 
straight  or  curved  pieces ;  the  lower  end  of  the  upright  pipes  being  con- 
nected to  a  box  or  trough  containing  water,  divided  by  partitions,  causing 
the  gas  to  pass  up  and  down  alternately,  as  shown  in  Figs.  103  and  104. 
Tarry  matters  and  more  ammoniacal  liquor  are  again  obtained,  which  finds 
its  way  to  the  tar-well. 

The  gas  after  circulating  through  the  condensers  still  contains  impuri- 
ties, which  are  removed  by  passing  it  through  an  apparatus  known  as  the 
scrubber,  consisting  essentially  of  cylindrical  wrought-iron  towers  filled  with 
coke,  over  and  through  which  trickles  a  light  flow  of  water,  or  better,  weak 
ammoniacal  liquor ;  the  gas  passing  upward,  meets  this  downward  flow  of 
liquid,  and  to  it  gives  up  the  hydrogen  sulphide  contained,  with  the  forma- 
tion of  ammonium  sulphide,  etc.  Tarry  matters  again  are  separated,  and 
in  time  cause  the  coke  to  become  somewhat  clogged.  This  apparent  draw- 
back has  led  to  the  introduction  of  perforated  iron  plates  in  place  of  the 


364     INDUSTRIES  BASED   UPON  DESTRUCTIVE  DISTILLATION. 


FIG.  103. 


coke,  or,  what  has  also  proved  equally  efficient,  wooden  lattice  screens. 
Anderson's  rotating  scrubber  consists  of  brushes,  which  while  rotating  dip 
into  a  trough  of  ammoniacal  liquor,  and  thereby  perform  functions  similar  to 
the  means  above  mentioned.  Another  form  of  scrubber  consists  of  a  tower 
containing  cast-iron  plates  provided  with  perforations, 
through  which  ammoniacal  liquor  passes  in  its  down- 
ward course,  meeting  the  gas.  The  liquid  is  contin- 
uously pumped  to  the  top,  when  it  again  passes 
down,  coming  in  contact  with  fresh  gas.  This  is 
repeated  until  the  liquor  has  taken  up  sufficient  am- 
monia to  make  it  available  to  the  ammonia  sulphate 
manufacturer.  From  the  scrubber  the  gas  passes  on 
to  the  purifiers,  where  the  hydrogen  sulphide  still 
remaining,  carbon-disulphide  vapor,  and  the  carbonic 
acid  are  removed.  The  purifiers  ordinarily  used  con- 
sist of  a  large  shallow  box,  constructed  of  cast  iron 
in  sections,  and  bolted  together,  or  of  wrought-iron 
plates,  provided  with  a  cover,  the  edge  of  which 
dips  in  water  contained  in  a  channel  provided  at  the 
top  of  the  box,  acting  as  a  seal  and  preventing  the 
escape  of  gas  at  that  point,  as  shown  in  Fig.  1 05.  The 
purifying  agent  generally  employed  is  slaked  lime, 
which  is  spread  upon  wood  screens,  within  the  box, 
from  four  to  six  in  number,  one  above  the  other,  and 
supported  by  ledges.  Hydrogen  sulphide  and  carbon 
dioxide  are  absorbed  by  the  lime,  while  compounds 
of  cyanogen  are  at  the  same  time  decomposed. 

Four  purifiers  are  generally  used,  three  being  in 
service,  while  the  fourth  is  reserved  charged  with 
fresh  lime.  Gas  enters  the  one  containing  the  oldest 
lime,  and  when  it  is  noticed  that  lead-acetate  paper 
is  discolored  by  some  of  the  gas  acting  upon  it,  it  is 
known  that  the  purifying  material  is  saturated ;  this 
purifier  is  discontinued,  and  the  freshly-charged  one 
placed  in  service.  In  this  manner  they  are  con- 
tinually rotated. 

Ferric  hydrate  (hydrated  ferric  oxide)  is  also  largely  employed  in  gas  puri- 
fication,— Laming  process.  Gas  charged  with  hydrogen  sulphide  coming  in 
contact  with  the  above  causes  a  reduction  to  ferrous  sulphide,  at  the  same 

FIG.  104. 


time  some  sulphur  is  deposited,  with  the  formation  of  water.  This  process 
does  not  absorb  the  carbon  dioxide  from  the  gas;  for  this  purpose  lime 
is  mixed  with  the  ferric  hydrate,  together  with  some  cinders  or  sawdust,  in 
order  that  the  whole  may  be  porous,  and  resist  as  little  as  possible  the  pas- 
sage of  the  gas.  When  the  purifying  action  has  ceased,  simply  exposing 


PROCESSES  OF  TREATMENT. 


365 


the  inert  mixture  to  the  action  of  the  air  for  a  while  restores  its  properties, 
until  after  repeated  use  it  becomes  so  charged  with  separated  sulphur  that 
it  is  no  longer  available. 

The  introduction  of  free  oxygen  into  the  gas,  previous  to  it  entering  the 
purifiers,  has  been  found  to  lengthen  the  time  during  which  the  oxide  of 
iron  can  remain  without  being  changed,  thereby  saving  much  handling.  It 


FIG.  105. 


has  also  improved  the  illuminating  power  of  the  gas.  (Journ.  Soc.  Chem. 
Ind.,  vol.  viii.  pp.  84  and  694.) 

From  the  purifiers  the  gas  passes  through  the  meter  of  the  works, 
where  the  volume  is  registered,  then  on  to  the  gas-holders,  where  it  is  stored 
and  from  which  it  is  distributed. 

The  following  table  illustrates  the  composition  of  illuminating  gas 
taken  from  various  stages  of  manufacture : 


Entering 
the  air  con- 
denser. 

Entering 
the 
scrubber. 

Entering 
the 
Laming's 
purifier. 

Entering 
the  lime- 
purifier. 

Entering 
the  gas- 
holder. 

Hydrogen    

37.97 

37  97 

37.97 

37.97 

37.97 

Marsh-<j;as  

39.78 

38.81 

38.48 

40/29 

39.37 

Carbonic  oxide 

7  21 

7  15 

7  11 

3  93 

3  97 

Heavy  hydrocarbons     .    . 

4  19 

4  06 

446 

4  66 

429 

4.81 

4  99 

6  89 

7  86 

9  99 

Oxygen    

0.31 

047 

0  15 

048 

0  ')! 

Carbon  dioxide      

3.72 

3  87 

3  39 

3  33 

041 

Hydrogen  sulphide    . 

1.06 

1.47 

0  56 

0  36 

Ammonia    ,    .    . 

095 

0  54 

2.  COKE-OVEN  DISTILLATION  OF  COAL. — The  burning  of  coke  in  pits, 
"  meilers,"  or  mounds,  represents  the  first  rough  and  wasteful  method  of 
converting  bituminous  coal  into  coke;  involving,  at  the  same  time,  the 
total  loss  of  all  the  volatile  matter  of  the  coal.  It  allows,  however,  of  the 
smothering  the  finished  coke  with  fine  dust,  instead  of  requiring  it  to  be 
quenched  with  water,  as  in  other  methods.  The  so-called  "  bee-hive"  ovens 
allow  of  the  volatilizing  of  a  much  greater  amount  of  sulphur  in  the  coal, 
and  give  a  decidedly  increased  yield  of  coke  over  the  pit-burning  method. 


366      INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

The  charge  can  be  run  through,  too,  in  less  than  half  the  time.  Some  air  is 
admitted  in  both  cases,  with  consequent  loss  of  coke,  and  no  attempt  is 
made  to  save  the  residuals  in  either  case. 

The  distillation  of  coal  in  ovens  diifers  materially  from  the  older  methods 
of  production  in  piles  or  kilns  in  that  the  inflammable  gases  given  off  are 
to  some  extent  utilized. 

The  AppoWs  oven  consists  of  a  series  of  vertical  retorts  built,  generally, 
in  two  rows,  enclosed  by  brick  walls.  Each  retort  is  surrounded  by  air- 
spaces which  are  in  communication  one  with  the  other,  and  with  the  inside  of 
each  retort.  It  is  within  this  air-space  that  combustion  of  the  gases  gener- 
ated by  the  decomposition  of  the  coal  occurs ;  air  having  been  permitted 
to  enter  through  openings  for  the  purpose.  The  bottom  of  each  retort  is 
provided  with  a  large  door,  which  is  opened  to  permit  the  charge  of  finished 
coke  to  fall  into  a  pit  built  for  the  purpose. 

The  Coppee's  oven  is  mainly  employed  in  the  coking  of  finely-divided  coal. 
The  shape  of  each  chamber  is  long,  slightly  tapering,  to  facilitate  the  re- 
moval of  the  coke,  narrow,  and  of  a  height  equal  to  about  three  times  the 
width.  The  gaseous  products  pass  from  the  oven  through  vertical  flues, 
built  in  the  walls  dividing  the  ovens,  which  open  into  horizontal  flues  under 
each  chamber,  thereby  thoroughly  distributing  the  heat.  The  waste  gases 
are  either  led  under  steam-boilers,  or  are  allowed  to  pass  directly  to  the 
open  air. 

The  Simon-Carves'  oven,  illustrated  in  Fig.  106,  is  similar  in  construction 
to  the  Coppe"e  oven,  but  provision  is  made  for  the  recovery  and  utilization  of 
the  by-products.  Mr.  Henry  Simon,  C.E.,  in  an  address  before  the  British 
Iron  and  Steel  Institute  (Journ.  Iron  and  Steel  Inst.,  No.  1,  1880),  states : 
"  According  to  our  system,  the  coal  is  rapidly  carbonized  by  subjecting  a 
comparatively  thin  layer  of  it  to  a  high  temperature  in  a  closed  and  retort- 
like  vessel,  and,  whilst  in  the  bee-hive  ovens  the  volatile  products  are 
burned  inside,  we  burn  them  around  and  outside  of  this  retort-like  vessel, 
and  only  after  they  are  deprived  of  the  tar  and  ammoniacal  liquor.  Each 
oven  is  in  the  form  of  a  long,  high,  narrow  chamber  of  brick-work,  and  a 
number  of  these  are  built  side  by  side,  with  partition-walls  between  them 
sufficiently  thick  to  contain  horizontal  flues.  Flues  are  also  formed  under 
the  floor  of  each  oven,  and  at  one  end  of  these  is  a  small  fireplace,  consist- 
ing of  a  fire-grate  and  ash-pit,  with  suitable  door,  the  fire-door  having 
fitted  above  it  a  nozzle,  through  which  gas  produced  from  the  coking  is 
admitted  to  form  a  flame  over  some  fuel  burning  on  the  grate.  Only  a 
very  trifling  amount  of  such  fuel,  consisting  exclusively  of  the  small  refuse 
coke,  is  used  here,  its  function  being  really  more  that  of  igniting  the  gas 
than  that  of  giving  off  heat.  These  grates  are  not  charged  with  fuel  more 
than  twice  in  each  twenty-four  hours  when  in  regular  work.  The  products 
of  combustion  pass  from  the  fireplace  along  a  flue  under  the  oven  floor  to 
the  end  farthest  from  the  fire.  They  return  along  another  flue  under  the 
floor  to  the  fire  end ;  they  then  ascend  by  a  flue  in  the  partition- wall  to  the 
uppermost  of  several  horizontal  flues  formed  therein,  and  descend  in  a  zig- 
zag direction  along  these  flues,  finally  passing  into  a  horizontal  channel 
leading  to  a  chimney.  The  oven  in  consequence  is  evenly  heated  at  the 
bottom  and  sides,  and  the  coal  contained  is  rapidly  and  completely  coked. 
No  air  enters  the  chambers,  the  only  openings  being  for  the  escape  of  the 
volatile  products.  The  improved  ovens  are  fed  with  coal  by  openings  in 
the  roof,  over  which  coal-trucks  are  run  on  rails ;  and  the  coal  is  evenly 


PROCESSES  OF  TREATMENT. 
FIG.  106. 


367 


368     INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

distributed  by  rakes  introduced  at  end  openings,  provided  with  doors  faced 
with  refractory  material,  which  doors  are  closed  and  kept  tightly  luted 
while  the  oven  is  in  operation.  The  feed-holes  in  the  roof  are  also  provided 
with  covers.  Through  the  middle  of  the  roof  rises  a  gas-pipe  provided 
with  a  hydraulic  valve,  which  closes  the  passage  by  a  lip  projecting  down 
from  it  into  an  annular  cavity  surrounding  its  seating,  in  which  it  is  im- 
mersed in  a  quantity  of  tar  and  ammoniacal  liquor,  lodged  there  during 
previous  distillations.  The  volatile  products  of  the  coal  distillation  rise  by 
the  gas-pipe,  and  are  led  through  a  range  of  pipes  kept  cool  by  external 
wetting,  so  that  the  tar  and  ammoniacal  liquor  become  condensed  and  sepa- 
rated from  the  combustible  gas."  When  the  charge  of  coal  has  been  con- 
verted to  coke,  it  is  removed  from  the  ovens  by  means  of  a  piston  worked 
by  an  engine  traversing  rails  in  front  of  the  battery.  The  yield  of  coke 
has  been  stated  to  be  from  seventy-five  to  seventy-seven  per  cent,  of  the 
coal.  During  a  run  of  two  hundred  and  fifteen  days,  the  yield  of  residuals 
averaged  27.70  gallons  of  ammoniacal  liquors  per  ton  of  coal  carbonized, 
and  6.12  gallons  of  tar  per  ton  of  coal  carbonized. 

The  yield  of  residuals  in  the  Coppee-Otto  oven  has  been  found  to 
average  25.44  pounds  of  sulphate  of  ammonia  and  60.84  pounds  of  tar 
per  ton  of  coal  used. 

The  Jameson  oven,  structurally  considered,  is  but  a  simple  modification 
of  the  common  bee-hive  oven,  and  is  made  by  introducing  channels  in  the 
floor  of  the  oven  radiating  from  the  centre.  These  channels  are  covered 
with  perforated  tiles,  and  are,  from  the  centre  of  the  oven  (where  the  chan- 
nels are  lowest),  connected  by  means  of  pipes  which  lead  to  an  exhausting 
apparatus,  and  also  for  the  discharge  of  the  products  of  distillation.  In 
this  process  the  products  are  removed  as  soon  as  they  are  formed,  being 
drawn  down  by  means  of  the  suction  applied  through  the  mass  of  cooler 
coal  than  that  from  which  they  were  generated. 

Considerable  difference  exists  between  the  tars  obtained  from  the  Simon- 
Carve's  and  the  Jameson  coking  processes.  The  first-mentioned  tar  has  a 
specific  gravity  of  1.106,  and  closely  resembles,  chemically,  the  tars  pro- 
duced in  the  illuminating  (retort)  gas  process,  both  being  obtained  at  a  high 
temperature.  The  Simon-Carve's  tar  is  rich  in  naphthalene  and  anthracene, 
but  low  in  naphtha,  benzene,  phenols,  etc.  The  Jameson  tar  is  a  low  tem- 
perature tar,  with  a  specific  gravity  varying  from  .960  to  .994,  and  contain- 
ing no  benzene,  but  trifling  amounts  of  toluene  and  xylene,  while  a  consid- 
erable proportion  of  phenoloid  bodies  are  found,  containing,  at  the  most,  a 
very  small  quantity  of  carbolic  acid.* 

3.  FRACTIONAL  SEPARATION  OF  CRUDE  COAL-TAR. — Following  gas 
retort  distillation,  in  point  of  technical  importance  is  certainly  the  distilla- 
tion of  the  coal-tar  obtained  from  the  former  processes  and  the  separation 
therefrom  of  certain  constituents  which  have  a  wide  application  in  several 
industries.  The  same  general  mechanical  arrangement,  though  somewhat 
simplified,  is  employed,  consisting  of  a  still,  a  condenser,  and  a  receiver. 
The  still  should  be  constructed  entirely  of  wrought  iron,  and  can  be  either 
horizontal  or  vertical.  Horizontal  stills  are,  according  to  Lunge,  far  less 
economical  than  the  vertical.  Fig.  107  is  a  vertical  section  of  a  tar-still 
showing  the  construction  and  fittings.  The  heat  from  the  fire  on  the  grate  6 

*  Consult  Journ.  Soc.  Chcm.  Ind.,  1883,  p.  495,  for  tables  of  analyses  of  Simon-Carve'i 
and  Jameson  tars. 


PROCESSES  OF  TREATMENT. 


369 


is  prevented  from  impinging  against  the  concave  bottom  of  the  still  by  means 
of  the  arch  g,  but  passes  through  the  openings  h  in  the  circular  wall  k  into 
vertical  flues  i,  from  which  it  enters  the  annular  space  I  and  through  flues  in 
the  front  of  the  still  to  the  upper  space  n,  finally  entering  the  flue  p,  which 
leads  to  the  chimney.  The  supply-pipe  r  is  for  feeding  the  still,  the  pipe  .9 
is  an  overflow,  and  serves  to  indicate  when  the  tank  is  full.  The  cock  a  is 
for  drawing  off  the  pitch.  The  still-head  t  is  for  conducting  the  vapors,  and 

FIG.  107. 


is  connected  with  the  condenser.  The  svstem  of  pipes  x  y  z  indicated  is  for 
conducting  superheated  steam  into  the  still  for  finishing  the  distillation  ;  the 
pipes  conforming  to  the  shape  of  the  bottom,  are  provided  with  a  number 
of  jets  for  a  more  equal  distribution  of  the  steam.  The  remaining  attach- 
ments require  no  further  mention. 

The  condenser  consists  of  a  coil  of  pipe  immersed  in  water  contained  in 
an  iron  tank.     In  England,  the  pipe  used  is  from  six  to  nine  feet  in  length, 


370    INDUSTEIES  BASED  UPON  DESTEUCTIVE  DISTILLATION. 


and  from  four  to  six  inches  in  diameter ;  the  total  length  for  one  still  is 
calculated  at  from  one  hundred  and  forty  to  two  hundred  feet.  In  Ger- 
many, preference  is  given  to  worms  of  iron  (or  lead,  in  which  case  the  pipe 
from  the  still  must  be  continued  below  the  surface  of  the  water  in  the  con- 
denser and  join  the  worm  there,  in  order  to  obviate  the  possibility  of  it 
being  melted),  made  of  two-inch  pipe,  and  mounted  in  circular  tanks  pro- 
vided with  a  steam-pipe  for  heating  the  water,  and  also  with  a  small  pipe 
connected  with  the  worm  for  blowing  in  steam  whenever  it  is  necessary 
to  clean  it. 

Connected  with  the  condenser,  and  located  at  a  safe  distance  from  the 
still,  is  the  receiver,  which  can  be  of  any  convenient  shape,  and  of  such  a 
size  as  to  contain  the  whole  of  one  fraction  ;  or  a  number  can  be  employed, 
each  acting  as  a  store-tank  and  receiver.  For  the  receivers  to  contain  the 
volatile  fractions,  tight-closing  covers  must  be  supplied  to  guard  against 
evaporation  and  fire,  and  the  one  containing  the  first  fraction  to  have  means 
for  separating  the  oily  from  the  watery  layer.  The  receivers  for  the  oils 
which  deposit  crystalline  matter  to  be  so  arranged  that  they  can  be  easily 
cleaned. 

"  Coal-tar  (Allen,  Commercial  Organic  Analysis,  3d  ed.,  vol.  ii.,  Part  ii. 
p.  47),  as  obtained  as  a  by-product  in  the  manufacture  of  illuminating 
gas,  is  a  black  viscid  fluid  of  a  characteristic  and  disagreeable  odor.  The 
specific  gravity  ranges  from  1.10  to  1.20,  being  usually  between  1.12 
and  1.15. 

"  As  coal-tar  is  always  more  or  less  mixed  with  ammoniacal  liquor,  the 
constituents  of  the  latter  liquid  are  present  in  addition  to  those  of  the  tar 
proper,  and  the  constituents  of  the  illuminating  gas  itself  are  also  present 
in  a  state  of  solution. 

"  The  first  treatment  of  coal-tar  on  a  large  scale  consists  in  distilling  it 
in  iron  retorts  and  collecting  the  distillate  in  three  or  four  fractions.  The 
temperatures  at  which  the  receivers  are  changed  vary  considerably  with  the 
practice  of  different  works,  and  hence  the  products  are  far  from  being 
strictly  parallel." 

The  annexed  table  indicates  the  three  most  important  methods  of  frac- 
tionation : 


A. 

B. 

C. 

Product. 

Distilling- 
point  °  C. 

Product. 

Distilling- 
point  °  C. 

Product. 

Distil]  ing- 
point  °C. 

Crude  naphtha, 
or  light  oils    . 
Heavy  oils,  dead 
oils,    or    creo- 
sote oils  .    .    . 
Anthracene  oils 

0  to  170 

170  to  270 
above  270 

First  runnings, 
or  first  light 
oils     .... 
Second  light  oils 
Carbolic  oils     . 
Creosote  oils 

0  to  110 
110  to  210 
210  to  240 
240  to  270 

Light  naphtha 
Light  oils  .    .    . 
Carbolic  oils     . 
Creosote  oils     . 
Anthracene  oils 
Pitch             .    . 

Oto  110 
110  to  170 
170  to  225 
225  to  270 
270  to  360 

Pitch  . 

A  nthracene  oils 

above  270 

Pitch 

The  principal  constituents  of  coal-tar  are  separated,  one  from  the  other, 
by  means  of  fractional  distillation,  a  process  depending  upon  the  fact  that, 
if  a  mixture  of  liauids,  each  having  a  different  boiling-point,  be  heated, 
the  one  having  the  lowest  will  pass  over  first,  and  if  the  temperature  is  not 


PROCESSES   OF  TREATMENT.  371 

increased  beyond  that  point  at  which  the  distillation  of  this  fraction  takes 
place,  no  other  constituent  will  come  over ;  if  the  temperature  be  gradually 
increased  the  others  will  follow  in  the  order  of  their  boiling-points.  In 
cases  where  the  boiling-points  are  close,  and  even  in  others  where  they  are 
widely  differing,  the  action  of  one  substance  upon  another  often  prevents 
exact  separations. 

The  hot  stills  (from  the  previous  working)  are  charged  wfth-fresh  tar, 
all  the  openings  are  then  closed,  and  the  fire  carefully  watched  in  order  that 
no  undue  rise  in  temperature,  and  consequent  boiling  over  of  the  contents, 
may  take  place.  Gases,  ammonia-liquor,  and  light  oils  distil  over  at  170°, 
the  whole  being  designated  "first  runnings."  This  fraction  is  collected 
and  allowed  to  stand,  when  the  watery  portion  separates  more  or  less  com- 
pletely from  the  oils,  which  are  redistilled,  yielding  ammonia  boiling  under 
70°,  crude  benzol  at  140°,  which  is  subsequently  purified  with  sulphuric 
acid  and  distilled,  naphtha,  140°  to  170°,  treated  as  the  benzol,  yielding 
"  solvent  naphtha."  This  whole  fraction  has  a  specific  gravity  nearly  equal 
to  that  of  water.  The  second  fraction — "  middle  oil,"  or  "  carbolic  oil" — 
distils  over  from  170°  to  230°,  and  contains  the  impure  phenols  or  carbolic 
acid  and  naphthalene.  It  is  crystallized  and  pressed ;  the  mother-liquor  is 
agitated  with  caustic  soda  in  an  iron  tank,  the  alkaline  liquor  (carbolate  of 
soda)  decomposed  with  sulphuric  acid  separating  crude  carbolic  acid,  which  is 
distilled  and  crystallized,  yielding  liquid  and  pure  carbolic  acid  in  crystals. 
The  unchanged  oil  from  the  soda  treatment  is  returned  to  the  second  frac- 
tion for  re- working.  The  press-cake  from  the  first  treatment  of  this  frac- 
tion is  purified  with  sulphuric  acid,  distilled,  and  yields  naphthalene.  The 
third  fraction  constitutes  the  heavy  or  dead  oil,  so  called  from  the  fact  that 
the  specific  gravity  is  greater  than  water,  and  boils  from  230°  to  270°> 
occupying  a  position  between  middle  oil  and  the  anthracene  fraction.  It 
is  subjected  to  no  further  treatment,  but  is;  employed  chiefly  for  preserving- 
timber,  varnish  manufacture,  burning  for  lamp-black,  etc.  The  fourth  frac- 
tion, or  anthracene  oil,  boiling  over  270°,  constitutes  the  green  oil  or  green 
grease,  from  which,  upon  subsequent  treatment,  the  commercial  anthracene 
is  obtained.  This  fraction  is  allowed  to  stand  for  some  time,  in  order  to 
cool  and  to  separate  the  crystallizable  substances,  when  the  mass  is  drained 
from  the  excess  of  oil  and  pressed.  The  press-cake  is  crude  anthracene,  which 
is  dissolved  in  naphtha  and  known  as  fifty  per  cent,  anthracene.  The 
mother-liquor  from  the  first  pressing  with  the  drainings  are  redistilled,  crys- 
tallized and  pressed,  yielding  crude  anthracene,  treated  as  above,  and  an- 
thracene oil.  The  residue  in  the  still  constitutes  pitch,  which  is  withdrawn 
and  employed  for  making  pavements,  varnishes,  etc. 

The  annexed  diagram  from  Ost's  "  Lehrbuch  der  Technischen  Cbemie" 
graphically  represents  the  preceding  outline  of  the  tar  distillation  process. 

4.  TREATMENT  OF  AMMONIACAL,  LIQUOR. — The  ammoniacal  liquor  of 
the  gas-works  is  that  which  passes  out  continuously  from  the  scrubbers  and 
other  parts  of  the  process,  and  is  the  chief  source  of  nearly  all  the  am- 
monia of  commerce.  According  to  Lunge,  ordinary  gas-liquor  contains 
the  following ; 

(a)  Volatile  at  ordinary  temperatures. 

Ammonium  carbonates  (mono-,  sesqui-,  and  bi-). 
Ammonium  sulphide  (NH4)2S. 
Ammonium  hydrosulphide,  NH4.HS. 


372     INDUSTRIES   BASED   UPON   DESTRUCTIVE   DISTILLATION. 


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PROCESSES  OF  TREATMENT.  373 

Ammonium  cyanide. 
Ammonium  acetate  (?). 
Free  ammonia. 

(6)  Fixed  at  ordinary  temperatures. 
Ammonium  sulphate. 
Ammonium  sulphite. 
Ammonium  thiosulphate  (hyposulphite). 
Ammonium  thiocarbonate. 
Ammonium  chloride. 
Ammonium  thiocyanate  (sulphocyanide). 
Ammonium  ferrocyanide. 

The  salts  of  ammonia  that  are  volatile  are  readily  removed  from  the 
gas-1'quor  upon  simply  boiling,  or  by  the  aid  of  steam.  The  fixed  ammonia 
salts  require  the  addition  of  chemical  agents — e.g.,  lime — to  break  up  the 
combination  and  liberate  the  ammonia  which  is  eventually  recovered.  The 
greater  the  amount  of  volatile  ammonia  and  less  the  amount  of  the  non- 
volatile compounds,  the  greater  the  value  the  liquor  has  for  treatment. 

The  method  of  recovering  ammonia  at  a  London  works,  where  one  hun- 
dred thousand  gallons  of  liquor  are  treated  daily,  is  briefly  outlined  as  fol- 
lows :  The  liquor  is  pumped  into  a  large  settling-tank,  where,  after  remain- 
ing for  a  day  or  more,  it  is  pumped  into  a  "  Coffey"  still,  thirty  feet  high, 
into  which  steam  at  two  atmospheres  pressure  is  blown.  By  this  treatment 
the  volatile  ammonium  compounds  are  separated  from  the  water  and  the 
non-volatile  compounds.  Carried  along  with  the  steam,  the  volatile  com- 
pounds pass  from  the  still  through  a  worm,  provided  with  half-inch  holes, 
into  a  sheet-lead  saturator  filled  two-thirds  with  140°  Twaddle  sulphuric 
acid  and  water.  This  water  so  dilutes  the  acid  that  it  prevents  the  ammo- 
nium sulphate  from  crystallizing  within  the  saturator.  After  saturation, 
steam  is  blown  through  the  solution  to  remove  hydrogen  sulphide,  which, 
after  poss'ng  through  a  condenser,  is  burned  ;  the  heat  generated  being 
partly  utilized  in  the  production  of  steam  for  the  operation.  The  saturated 
liquid  is  run  off  into  leaden  pans  placed  over  a  fire,  and  evaporated  to  such 
a  point  that  the  sulphate  will  crystallize  out.  The  residual  mother-liquor  is 
made  use  of  in  the  dilution  of  the  sulphuric  acid  in  the  saturator. 

Without  going  into  the  details  of  construction  of  the  many  improve- 
ments made  in  the  apparatus  employed  for  the  recovery  of  ammnn'a,  it  may 
be  well  to  mention  the  apparatus  of  Gruneberg  and  Blum,  Fig.  108.  A  is 
the  column,  B  the  economizer  through  which  the  gas-liquor  j  asses  before 
entering  the  still,  and  is  heated  by  means  of  steam  or  waste  gases.  C  *s  the 
pump  which  introduces  the  lime  into  the  lime-vessel  F.  D  is  the  acid-tank 
or  satnrator.  The  gas-liquor  enters  the  still  at  the  top  and  descends  from 
chamber  to  chamber,  meeting  the  upward  current  of  steam,  till  it  reaches  the 
lime-d^composition-tank  F,  and  finally  the  boiler  G.  In  this  is  a  peculiar 
truncated  cone,  /,  over  which  flows  the  liquor  from  step  to  step,  and  owing  to 
the  increased  area  of  each  step  the  liquor  becomes  thinner  and  thinner,  per- 
mitt:nir  the  steam  to  act  very  thoroughly.  The  ammonia  generated  passes 
from  the  st:ll  through  the  pipe  P  to  the  saturator  D.  Waste  gases  collect  in 
the  bell  <?,  from  which  they  are  led  to  the  economizer  B,  and  finally  burned. 

Feldmann'%  apparatus  is  a  steam  still,  capable  of  recovering  both  the 
volatile  and  fixed  ammon:a,  and  occupies  very  little  space.  It  consists  of  a 
chambered  column,  lime-tank,  and  an  auxiliary  column,  in  connection  with 


374     INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

feed-tanks,  economizer,  lime-pump,  and  saturator.  The  liquor  flows  from 
the  feed-tanks  through  the  economizer,  where  it  is  heated,  to  the  top  of  the 
main  column,  down  which  it  flows  successively  through  the  chambers  in 
which  it  is  boiled  into  the  decomposing-tank,  which  contains  lime,  where  it 
is  thoroughly  agitated  with  steam.  The  liquor  flows  from  this  tank  to  the 
auxiliary  column,  similar  to  the  first  one,  where  the  little  ammonia  found  is 
driven  out.  The  spent  liquor  collects  in  the  lower  compartment,  from  which 
it  constantly  flows  away.  Lunge  states  that  an  apparatus  to  distil  from 


eight  to  ten  tons  of  ammoniacal  liquor  daily  occupies  a  space  of  seventeen 
feet  by  thirteen  feet  by  ten  feet. 

The  sulphate  of  ammonia  as  it  is  fished  from  the  saturators  is  allowed 
to  drain,  sometimes  slightly  washed  with  water,  and  sold  without  drying. 

m.  Products. 

Under  this  head  will  be  considered  the  more  important  products  that 
are  obtained  by  the  subsequent  treatment  of  the  main  fractions  of  the  dis- 
tillation process  as  indicated  on  previous  pages. 

1.  FIRST  LIGHT  OIL  is  the  fraction  distilling  at  a  temperature  up  to 
1 70°  C.  It  includes  a  small  percentage  of  ammonia-liquor  which  is  mechani- 
cally contained  in  the  tar,  and  is  separated  from  the  tar  oils  by  being  al- 
lowed to  stand  and  settle  out  when  it  is  drawn  oif.  The  specific  gravity  of 
the  fraction  is  about  .975,  and  is  made  up  of  benzene,  toluene,  and  higher 
homologues,  with  phenol,  cresol,  naphthalene,  etc.  The  products  obtained 
from  it  are  separated  by  redistilling  the  whole  fraction  in  a  small  still  of 


PRODUCTS.  375 

the  same  general  type  as  the  large  tar-still.     The  separate  distillates  are  gen- 
erally as  follows : 

First  Light  Oil  up  to  170°  yields 

(a)  To  110° "90  per  cent,  benzol." 

(b)  110°  to  140° "  50  per  cent,  benzol." 

(c)  140°  to  170° solvent  naphtha. 

The  fraction  obtained  up  to  110°  is  chemically  washed,  being-  agitated 
with  sulphuric  acid  of  1.84  specific  gravity  in  the  proportion  of  one  pound 
to  one  gallon  of  oil,  which  combines  with  the  bases,  dissolves  resins,  etc. 
The  agitation  is  carried  out  in  cast-iron  or  lead-lined  wooden  tanks  securely 
covered  to  prevent  loss  of  the  volatile  bodies,  and  provided  with  mechanical 
means  for  mixing.  This  is  completed  in  ten  or  fifteen  minutes,  when  the 
whole  is  allowed  to  stand  at  rest  for  an  hour  or  mure,  and  then  the  spent 
acid  is  completely  removed.  The  oil  is  now  thoroughly  washed  four  or 
five  times  with  water,  until  no  color  is  imparted  to  the  washings,  which 
should  have  but  a  slight  acid  reaction.  Agitation  is  again  continued,  but 
with  a  ten  per  cent,  caustic  soda  solution,  afterwards  allowed  to  separate, 
when  the  alkaline  solution  is  removed,  when  the  oil  is  finally  washed  with 
water  and  distilled,  either  by  means  of  fire  or  steam. 

(a)  "Ninety  per  Cent.  Benzol." — The  product  coming  over  at  110°  is  desig- 
nated "  ninety  per  cent,  benzol,"  from  the  fact  that  ninety  per  cent,  by  vol- 
ume of  it  distils  before  the  thermometer  rises  above  100°  C.     A.  H.  Allen 
(Commercial  Organic  Analysis,  2d  ed.,  p.  489)  states :  "  A  good  sample 
should  not  begin  to  distil  under  80°  C.,  and  should  not  yield  more  than 
twenty  to  thirty  per  cent,  at  85°,  or  much  more  than  ninety  per  cent,  at 
100°.     It  should  wholly  distil  below  120°.  ...  The  actual  percentage 
composition  of  a  ninety  per  cent,  benzol  of  good  quality  is  about  seventy 
per  cent,  benzene,  twenty-four  per  cent,  toluene,  including  a  little  xylene,  and 
four  to  six  per  cent,  of  bisulphide  of  carbon  and  light  hydrocarbons.     The 
proportion  of  real  benzene  may  fall  as  low  as  sixty  or  rise  as  high  as 
seventy  per  cent.     Ninety  per  cent,  benzol  should  be  free  from  opalescence 
and  colorless  ('  water  white').     The  specific  gravity  is  between  .88  and  .888 
at  15.5°  C.  (=  60°  F.),  but  this  is  not  a  true  guide  as  to  the  quality,  from  the 
fact  that  bisulphide  of  carbon  (specific  gravity  1.27)  and  light  hydrocarbons 
(specific  gravity  .86)  sensibly  affect  the  specific  gravity  of  the  benzol." 

(b)  "  Fifty  per  Cent.  Benzol"  is  a  product  of  the  fraction  boiling  from 
110°  C.  up  to  140°  C.,  and  is  subjected  to  the  same  treatment  as  the  previ- 
ous one.     The  specific  gravity  of  this  benzol  varies  from  .867  to  .872  in 
the  Scotch,  to  .878  to  .88  in  the  English,  samples.     Is  nearly  free  from 
bisulphide  of  carbon,  and  contains  little  hydrocarbons,  while  the  per  cent, 
of  toluene  and  xylene  are  greater  than  in  the  ninety  per  cent,  benzol. 

The  benzols  as  such  are  not  employed  in  the  arts  to  a  very  great  extent, 
but  when  nitrated,  nitrobenzene  (mirbane  oil)  is  obtained,  which  is  used  as 
such  for  scenting  soaps  and  pomades ;  and  when  this  nitrobenzene  is  reduced 
by  iron  turnings,  etc.,  aniline  oil  is  produced,  which  enters  largely  into  the 
manufacture  of  many  of  the  artificial  coloring  matters. 

(c)  Solvent  Naphtha — so  called  from  the  use  to  which  it  is  put, — dissolv- 
ing caoutchouc  in  the  manufacture  of  water-proof  materials,  etc., — follows 
the  benzols,  boiling  over  140°,  and  consists  of  xylene,  pseudocumene,  and 
mesitylene.     In  some  works  the  distillation  of  this  fraction  is  not  driven  to 
the  end,  but  stopped  when  the  product  yields  ninety  per  cent,  at  150°,  the 
residue  being  distilled  as  burning  naphtha  with  a  specific  gravity  of  .90. 


376     INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

Lunge  states:  "From  the  product  distilled  up  to  140°  may  be  extracted 
sixty  or  seventy  per  cent,  of  fifty  per  cent,  benzol,  twenty  to  twenty-five 
per  cent,  of  carburetting  and  solvent  naphtha,  five  to  eight  per  cent,  of 
burning  naphtha.  The  product  distilled  between  140°  and  170°  yields 
twenty-five  to  fifty  per  cent,  best  naphtha,  fifty  to  twenty-five  per  cent, 
burning  naphtha,  and  twenty-five  per  cent,  residue  in  the  still."  The 

FIG.  109. 


separation  of  the  preceding  into  benzene,  toluene,  xylene,  etc.,  for  the  use 
of  the  color  manufacturer,  is  not  ordinarily  carried  out  in  the  tar-distillery, 
but  at  the  color-works,  in  especially  constructed  column  stills.  The  appear- 
ance of  such  a  benzene  rectification  -till  is  shown  in  Fig.  109.  For  details 
of  construction  ot  such  a  column  still,  see  Chapter  VI.  p.  222. 

The  following  table  (Lunge,  "Coal  Tar  and  Ammonia,"  2d  ed.,  p.  476) 
shows  the  yield  in  percentage  volumes  of  the  products  from  the  light  tar  oils  : 


PRODUCTS. 


377 


Initial 

or 

or 

Op 

Op 

Op 

Op 

Op 

op 

COMMERCIAL  PRODUCTS. 

boiling 
points. 

88. 

93. 

100. 

110. 

120. 

130. 

138. 

149. 

160. 

171. 

"  Ninety  percent,  benzol" 
"  Fifty  per  cent,  benzol" 
Toluol 

82 
88 
100 

30 

65 
13 

90 
54 

74 
56 

90 
90 

Carburetting  naphtha  .  . 
Solvent  naphtha 

108 
110 

•    • 

1 

35 
17 

71 

57 

84 
71 

97 
90 

Burning  naphtha  .... 

138 

30 

71.6 

89 

2.  MIDDLE  OIL. — This  constitutes  the  second  main  fraction  in  the  tar 
distillation  process,  and  is  collected  between  170°  and  230°  C.,  yielding  upon 
further  treatment  two  very  important  and  valuable  products :  liquid  and 
solid  carbolic  acid  and  naphthalene,  both  of  which  find  their  widest  applica- 
tion in  the  artificial-color  industry,  although  large  quantities  are  employed 
for  many  other  purposes. 

While  this  fraction  is  coming  over  from  the  still,  no  cold  water  is  allowed 
to  run  into  the  condensing-tank,  for  the  reason  that  a  reduction  of  tempera- 
ture to  the  point  at  which  solid  naphthalene  would  form  in  the  condenser  is 
to  be  avoided  ;  a  steam-pipe  is  generally  led  into  the  tank,  and  the  water 
brought  to  50°  or  60°,  thereby  keeping  crystallizable  matter  in  a  fluid  con- 
dition and  continually  flowing. 

This  distillate  is  allowed  to  become  cold,  when  nearly  all  of  the  naph- 
thalene separates  in  leaflets,  which  are  dia'ntd  and  pressed  to  expel  the 
remaining  portions  of  the  non-crystallizable  oil,  which  is  the  source  of 
the  carbolic  acid. 

1.  Carbolic  Acid. — The  above  oils  are  thoroughly  mixed  with  a  solu- 
tion of  caustic  soda  (specific  gravity  1.26)  in  a  tank  provided  with  mechan- 
ical agitators,  or  with  means  for  forcing  air  through  the  liquids.  The 
mixing  is  performed  at  a  temperature  of  from  40°  to  50°,  and  is  com- 
pleted in  one  to  one  and  a  half  hours,  when,  after  standing  to  allow  the 
alkaline  liquors  to  subside,  they  are  drawn  off  and  cautiously  decomposed 
by  adding  sulphuric  acid  till  the  liquor  has  an  acid  reaction,  when  it  is  at 
once  removed  to  avoid  the  crystals  of  sodium  sulphate  forming  in  the  tank  ; 
the  carbolic  acid  is  allowed  to  stand  for  a  few  days  in  order  that  any  sodium 
sulphate  solution  remaining  may  separate  out,  when  it  is  washed  with  water 
and  finally  distilled  in  small  retorts,  yielding,  in  the  first  fraction,  water  and 
oil ;  in  the  second,  crystallizable  oil,  from  which  is  obtained  the  crystal  car- 
bolic acid  of  commerce ;  and  in  the  third  fraction,  the  non-cry  staUizable 
phenols,  or  liquid  carbolic  acid. 

That  part  of  the  mother-liquor  from  the  naphthalene  which  is  not  acted 
upon  by  the  caustic  soda  solution  added  to  remove  the  phenols  is  returned 
to  the  main  middle-oil  fraction  and  again  re-worked. 

Carbolic  Acid,  or  Phenol,  C6H6O  (or  C6H5OH). — All  compounds  contain- 
ing the  group  OH  in  place  of  one  or  more  of  the  hydrogen  atoms  of  ben- 
zene (C6H6)  or  its  homologues,  are  designated  Phenols.  Carbolic  acid  has 
a  very  peculiar  and  characteristic  odor,  burning  taste,  is  poisonous,  and  has 
preservative  properties ;  the  odor,  however,  is  not  so  pronounced  in  pure  as 
in  impure  specimens.  The  specific  gravity  at  0°  is  1.084.  crystall'zes  in 
colorless  rhombic  needles  which  melt  at  41°,  boiling  at  182°,  and  is  not 
decomposed  upon  distillation.  At  ordinary  temperature  it  dissolves  in 


378     INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 


FIG.  110. 


water  with  difficulty  (1  : 15),  but  is  soluble  in  alcohol,  ether,  glacial  acetic 
acid,  and  glycerine  in  all  proportions.  Upon  exposure  to  light  and  air  it 
deliquesces,  and  acquires  a  pinkish  color.  The  most  extensive  use  made  of 
it  is  as  a  raw  material  in  the  manufacture  of  many  of  the  artificial  color- 
ing matters, — picric  acid,  used  as  a  yellow  dye,  and  which  finds  considerable 
application  in  the  manufacture  of  a  number  of  high  explosives.  Large 
quantities  of  various  qualities  of  carbolic  acid  are  consumed  annually  for 
antiseptic  purposes,  both  for  domestic  use  and  in  surgery. 

2.  Naphthalene. — The  crude  crystals  which  were   obtained  when   the 
middle-oil  fraction  was  allowed  to  cool,  and  also  from  the  treatment  by  dis- 
tillation of  the  unchanged  oil  from  the  carbolic  acid  separation,  are  purified 
by  fusing  and  mixing  thoroughly  with  caustic  alkali,  if  impure,  followed  by 
a  washing  with  hot  water,  and  afterwards  with  sulphuric  acid ;  if  the  naph- 
thalene operated  upon  is  of  a  better  quality,  the  alkaline  treatment  may  be 
dispensed  with,  and  the  refining  commenced  with  the  acid,  which  is  of  1.453 
specific  gravity ;  Lunge  states,  however,  that  this  is  too  weak,  and  recom- 
mends an  acid  of  1.70  specific  gravity,  1.84   specific  gravity  being  still 
better.     The  amount  of  acid  used  varies  from  five  to  ten  per  cent. ;  the 
mixing  being  performed  in  lead-lined  tanks,  after  which  it  is  washed  with 

water  several  times,  and  to  remove 
the  remaining  traces  of  acid  weak 
caustic  liquor  is  used.  The  naph- 
thalene thus  purified  is  sublimed  in 
barrels  hung  over  melting-pots  suita- 
bly mounted,  or  in  frame  or  brick 
chambers  connected  by  proper  open- 
ings with  an  iron  melting-pan,  the 
general  construction  of  which  is 
shown  in  Fig.  110.  The  best 
naphthalene  is  produced  by  distil- 
lation from  stills,  which  are  made 
shallow,  with  a  very  high  dome.  Larger  quantities  are  handled  by  this 
method  than  by  subliming. 

Naphthalene,  C10H8,  is  one  of  the  principal  constituents  of  coal-tar,  occur- 
ring in  it  in  various  proportions  from  five  to  ten  per  cent. ;  it  is  also  formed 
when  the  vapors  of  organic  substances  are  passed  through  tubes  heated  to 
redness.  The  specific  gravity  of  naphthalene  when  solid  is  1.158,  at  its 
melting  point  (79.2°)  it  is  0.978  ;  it  boils  at  216.6°  C.  The  odor  is  pleasant, 
though  characteristic ;  volatilizes  to  some  extent  at  ordinary  temperature, 
but  readily  in  the  vapor  of  boiling  water.  Crystallizes  in  large,  silvery-bril- 
liant, thin  rhombic  plates,  which  are  faintly  soluble  in  hot,  but  insoluble  in 
cold,  water,  though  easily  in  methyl  and  ethyl  alcohols,  chloroform,  ether, 
benzene,  etc.  The  commercially  sublimed  naphthalene  is  from  seventy  to 
ninety-nine  per  cent.  pure.  Industrially,  it  is  employed  in  the  manufacture  of 
a  large  series  of  coloring  matters ;  as  an  enricher  ("  carburetter")  of  illumi- 
nating gas ;  and  when  specially  refined,  as  a  substitute  for  ordinary  cam- 
phor in  preventing  the  ravages  of  insects,  etc.,  in  woollen  goods. 

3.  CREOSOTE  OIL,  OR  HEAVY  OIL,  constitutes  the  third  main  fraction, 
and  is  generally  collected  from  230°  to  270°  C.,  or  until  it  is  noticed  that 
solid  matters  begin  to  crystallize,  which  indicates  that  the  anthracene  is  com- 
mencing to  distil.     In  order  to  prevent  any  cresols  from  contaminating  the 
phenol  and  naphthalene  of  the  previous  fraction,  that  fraction  is  not  driven 


PKODUCTS.  379 

to  completeness,  which  precludes  the  possibility  of  any  of  the  heavy  oil 
passing  over.  Any  naphthalene  contained  in  this  fraction  is  recovered  by 
crystallizing  and  pressing,  the  residual  oil  not  being  subjected  to  further 
treatment  is  employed  directly. 

The  oil  has  a  greenish-yellow  color,  and  is  very  fluorescent,  which  in- 
creases in  intensity  upon  exposure  to  light  and  air.  By  transmitted  light 
it  is  dark  red,  and  by  reflected  light  the  appearance  is  bottle-green.  The 
odor  is  unpleasant  and  extremely  characteristic.  It  is  heavier  than  water, 
the  last  portion  coming  from  the  still  being  as  high  in  specific  gravity  as 
1.10.  Creosote  oil  has  been  found  to  contain  naphthalene,  anthracene, 
phenanthrene,  phenol,  cresol,  etc.,  with  many  other  bodies  but  little  known. 
It  finds  its  widest  application  in  the  creosoting  or  preservation  of  timber; 
although,  to  a  limited  extent,  it  has  been  employed  as  a  fuel,  and  for  the 
production  of  illuminating  gas,  softening  hard  pitch,  as  a  lubricant,  for 
lamp-black  production,  etc. 

The  process  of  impregnating  timber  with  coal-tar  oils,  with  the  view  of 
preserving  it  against  decay,  dates  from  1838,  when  a  patent  was  granted  to 
John  Bethell.  This  process  consists  essentially  of  exhausting  the  already 
seasoned  timber  of  air  and  moisture  in  a  vacuum  maintained  by  means  of 
an  air-pump ;  when  the  exhaustion  is  complete,  the  tar  oil  is  allowed  to 
enter  the  vessel,  when  it  is  at  once  absorbed  by  the  pores  of  the  wood. 
Various  processes  have  been  suggested  from  time  to  time,  but  those  which 
have  given  the  most  complete  satisfaction  are  nearly  all  based  upon  the  one 
above  mentioned.  S.  B.  Boulton's  process  is  suited  to  the  treatment  of  raw 
timber,  and  is  similar  in  some  respects  to  BethelPs ;  the  vacuum  is  con- 
tinued after  the  creosote  oil  (having  been  previously  heated  to  100°  C.)  has 
entered  the  vessel,  the  oil  penetrating  the  pores  of  the  wood  very  thoroughly. 

4.  ANTHRACENE  OIL. — The  fraction  distilling  from  270°  C.  and  over 
consists  of  that  portion  of  the  tar  which  is  made  up  of  bodies  possessing 
the  highest  boiling  points,  and  is  distinguished  from  the  heavy  oil  fraction 
by  a  separation,  on  cooling,  of  solid  matters.  In  it  has  been  found  naph- 
thalene, methyl-naphthalene,  anthracene,  phenanthrene,  methyl-anthracene, 
pyrene,  carbazol,  etc.  With  the  exception  of  methyl-naphthalene,  which  is 
a  liquid,  all  the  others  are  solids  at  ordinary  temperature,  but  which  have 
high  melting  points. 

The  separation  of  the  crude  anthracene  from  the  distillate  is  accom- 
plished by  cooling  or  crystallizing,  and  pressing.  The  cooling  takes  place 
in  large,  shallow  iron  pans,  either  spontaneously  or  by  refrigeration,  when 
the  semi-solid  mass  is  transferred  to  bag  filters,  closed  at  the  lower  end, 
and  connected  by  means  of  nipples  at  the  upper  end  to  a  pipe  for  conduct- 
ing compressed  air,  which  acts  in  driving  the  liquid  or  non-solidifying  por- 
tion out,  and  leaving  the  mass  nearly  dry.  By  using  filter-presses  instead 
of  the  above,  a  larger  and  better  yield  can  be  obtained  in  a  shorter  time. 
The  crude  anthracene  is  placed  in  cloths  and  subjected  to  a  gradually- 
increasing  pressure  in  a  vertical  or  horizontal  hydraulic  press,  the  plates 
of  which  being  so  constructed  as  to  be  heated  by  steam,  or  the  whole  press 
may  be  enclosed  in  a  chest  to  which  steam  can  be  admitted.  Fig.  Ill 
illustrates  the  general  arrangement  of  a  press  suited  to  the  purpose.  The 
use  of  heat  in  the  pressing  is  to  cause  those  bodies  which  have  a  lower 
melting  point  than  that  of  the  anthracene  to  be  easily  removed.  The  yield 
of  anthracene  by  hot-pressing  only  comes  up  to  about  thirty  to  thirty-two 
per  cent,  of  the  oil  in  winter,  and  thirty-three  to  thirty-six  per  cent,  in 


380      INDUSTRIES  BASED  UPON   DESTRUCTIVE   DISTILLATION. 


FIG.  111. 


summer  (Lunge).  The  pressed  anthracene  is  ground  to  a  fine  po\vder,  and 
washed  with  solvent  naphtha  (which  removes  the  coal-tar  oils)  in  either  a 
horizontal  or  vertical  air-tight  boiler,  fitted  with  a 
steam  coil,  and  provided  with  a  mechanical  agitator. 
The  mixing  requires  several  hours  with  gentle  heat, 
when  the  whole  is  forced  by  compressed  air  to  a 
closed  filter,  which  separates  the  now  washed  anthra- 
cene from  the  naphtha. 

A  still  purer  anthracene  is  obtained  by  submit- 
ting this  product  to  sublimation  with  the  aid  of 
steam.  For  this  purpose  the  apparatus  shown  in 
Fig.  112  is  employed.  The  anthracene  is  melted 
in  an  iron  pan,  and  over  the  surface  of  the  melted 
mass  superheated  steam  is  blown.  The  anthracene 
vapors  are  carried  by  the  steam  into  a  cooling  cham- 
ber, where  they  are  condensed  by  coming  in  contact 
with  a  spray  of  cold  water. 

The  anthracene  oils  from  the  first  draining  of 
crude  material  are  usually  re-distilled  in  order  that 
the  anthracene  contained  in  them  may  be  recovered. 
Graham's  process  (Chem.  News,  xxxiii.  pp.  99, 168) 
for  this  is  to  distil  about  fifteen  hundred  gallons  of 
the  filtered  oils  from  a  clean  tar-still  until  crystals 
of  anthracene  are  noticed,  when  a  sample  of  the  dis- 
tillate is  allowed  to  cool,  at  which  point  the  operation 
is  stopped,  and  the  residue  in  the  still  is  run  out 
and  allowed  to  become  cold,  when  the  product  sepa- 
rates out.  This  is  filtered  and  pressed  in  the  manner  above  described  for 
the  first  crystallization. 

The  oils  which  yield  no  more  "anthracene  when  subjected  to  further 

treatment  are  added  to  the  creosote  oils,  or  else  employed  to  soften  pitch,  etc. 

Anthracene,  C14H10,  is  found  under  similar  conditions  to  those  giving 

rise  to  naphthalene,  and  was  discovered  in  1832  by  Dumas  and  Laurent, 

while  Fritzsche  was  the  first  to  find  it  in  coal-tar,  in  which  it  occurs  as  a 

FIG.  112. 


characteristic  constituent.  When  pure,  it  crystallizes  in  white,  lustrous, 
rhombic  plates,  which  exhibit  a  beautiful  violet  fluorescence.  Melts  from 
210°  to  213°  C.,  subliming  at  about  the  same  temperature  in  small  scales. 
It  is  insoluble  in  water,  sparingly  in  alcohol,  while  benzene,  essential  oils, 


ANALYTICAL  TESTS   AND   METHODS.  381 

light  tar  oils,  and  hot  alcohol  dissolve  varying  quantities.  When  oxidized 
it  yields  anthraquinone,  which  is  further  treated  in  the  processes  for  the  pro- 
duction of  the  valuable  alizarine  and  other  coal-tar  colors,  and  which  forms 
practically  the  only  utilization  for  anthracene. 

5.  PITCH. — By  pitch  is  understood  the  residue  remaining  in  the  still 
after  nearly  all  the  volatile  constituents  have  been  driven  off.  Formerly, 
what  remained  in  the  still  after  the  light  oils  were  distilled  was  called 
asphalt,  and  was  equivalent  to  about  eighty  per  cent,  of  the  tar,  consequently 
it  contained  those  constituents  mentioned  in  the  middle  oil  and  creosote  oil 
fractions,  with  the  anthracene.  This  method  of  fractionation,  however,  is 
not  followed,  but  the  distillation  is  generally  carried  to  that  point  when  the 
distillate  shows  a  specific  gravity  of  1.09,  when  soft  pitch  will  result.  If 
the  distillation  is  carried  further,  or  until  it  has  a  specific  gravity  of  1.12, 
hard  pitch  is  obtained.  In  some  cases  the  distillation  is  pushed  as  far  as 
the  still  will  stand  with  safety,  in  which  case  no  more  volatile  bodies  remain 
and  a  coke  virtually  remains.  As  a  rule,  a  moderately  hard  pitch  is  made, 
which  is  run  into  casks  or  barrels  directly  from  the  still. 

The  utilization  of  the  pitch  is  carried  out  in  several  ways  :  in  the  manu- 
facture of  patent  fuel  (briquettes)  when  incorporated  with  coal-dust  or  coke- 
refuse.  This  industry  has  but  little,  if  any,  importance  in  the  United  States, 
but  is  quite  extensive  in  Europe.  Briquettes  contain  from  five  to  eight  per 
cent,  of  pitch,  according  to  the  amount  of  pressure  employed  in  their  manu- 
facture. Good  grades  have  ten  per  cent,  more  heating  effect  than  ordinary 
steam  coals,  are  more  cleanly  and  economical. 

The  pitch  mixed  with  creosote  oil  to  the  consistency  of  paint  is  much 
employed  as  such  on  iron-  and  wood-work  where  a  black  coating  is  desir- 
able ;  various  other  substances  are  used  as  solvents  and  softeners,  notably 
carbon  bisulphide,  which  has  given  excellent  results.  In  street-paving,  the 
employment  of  the  pitch  has  superseded  the  use  of  the  natural  asphalt  to 
advantage.  Considerable  quantities  are  annually  consumed  in  the  manu- 
facture of  roofing-paper,  etc. 

IV.  Analytical  Tests  and  Methods. 

1.  VALUATION  OF  TAR  SAMPLES. — Practically,  the  most  efficient 
method  to  follow  for  the  determination  of  the  value  of  tar  samples  is  to 
distil  twenty  or  thirty  gallons  from  a  small  still,  in  the  same  manner  and 
under,  as  far  as  possible,  the  same  conditions  as  is  practised  in  the  distilla- 
tion of  tar  on  a  large  scale.  The  products  are  weighed  and  measured. 
When  a  small  still  is  not  accessible,  recourse  must  be  had,  for  laboratory 
purposes,  to  the  following  method,  which  gives  excellent  results  if  carefully 
attended  :*  "  Two  hundred  and  fifty  cubic  centimetres,  or  ten  ounces  meas- 
ure, of  the  tar  is  placed  in  a  retort  which  it  only  one-third  fills,  so  as  not 
to  spoil  the  distillate  if  there  is  much  frothing  during  distillation.  The 
retort  should  be  supported  on  a  cup-shaped  piece  of  coarse  wire  gauze, 
placed  in  an  aperture  in  a  sheet-iron  plate.  Over  the  retort  is  placed  a 
dome,  made  by  removing  the  bottom  from  a  tin  can  or  bottle,  and  cutting 
out  a  piece  of  the  side  to  allow  the  neck  of  the  retort  to  pass  through. 
This  contrivance  confines  the  heat,  and  prevents  the  distillate  or  heavy 
vapor  from  falling  back."  ..."  The  products  obtained  by  the  distillation 
are:  (1)  Ammoniacal  liquor;  (2)  total  light  oils;  (3)  creosote  oil;  (4)  an- 

*  A.  H.  Allen,  Commercial  Organic  Analysis,  3d  ed.,  vol.  ii.,  Part  ii.  p.  52. 


382     INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

thracene  oils ;  and  (5)  pitch.  In  obtaining  these  fractions,  the  character  of 
the  distillate  is  amply  sufficient  to  indicate  the  point  at  which  the  receiver 
should  be  changed.  No  thermometer  is  necessary,  nor  any  condensing  ar- 
rangement be  attached  to  the  retort.  The  lamp  being  lighted  (a  powerful 
Bunsen),  the  ammoniacal  liquor  and  naphtha  are  collected  together  in  a 
graduated  cylinder,  which  is  changed  when  a  drop  of  the  distillate — collected 
in  a  test-tube  of  water — begins  to  sink.  After  standing,  to  allow  perfect  sepa- 
ration of  the  ammoniacal  liquor  and  light  oils,  the  volume  of  each  is  observed, 
and,  if  desired,  the  strength  of  the  former  can  be  ascertained  in  the  usual 
way  by  distillation  with  lime  and  titration  of  the  distillate.  The  quantity  of 
light  oils  is  too  small  to  allow  of  any  further  fractionation  for  benzols,  etc. 

"  The  next  fraction  of  the  distillate  consists  of  creosote  oil.  At  first  it 
will  contain  much  naphthalene,  and  will  probably  solidify  in  white  crystals 
on  cooling,  but  afterwards  a  more  fluid  distillate  is  obtained.  At  a  still 
later  stage,  a  drop  of  the  distillate  collected  on  a  cold  steel  spatula  will  be 
found  to  deposit  amorphous  solid  matter  of  a  yellow  or  greenish-yellow 
color,  when  the  receiver  is  again  changed,  the  fraction  measured,  and,  if 
desired,  assayed  for  carbolic  acid  and  naphthalene. 

"  The  next  fraction  of  the  distillate  is  rich  in  anthracene,  and  not  un- 
frequently  condenses  in  the  neck  of  the  retort  as  a  yellow,  waxy  substance, 
which  may  be  melted  out  by  the  local  application  of  a  small  Bunsen  flame. 

"  The  collection  of  anthracene  oil  is  complete  when  no  more  distillate 
can  be  obtained,  and  the  pitch  intumesces  and  gives  oif  heavy  yellow  fumes. 
The  distilled  fraction  is  then  measured  and  cooled  thoroughly,  and  the 
resultant  pasty  mass  pressed  between  folds  of  blotting-paper,  weighed,  and 
assayed  for  real  anthracene  by  the  anthraquinone  test.  The  result  is 
calculated  into  crude  anthracene  at  thirty  per  cent.,  a  standard  .which  is 
generally  adopted  by  the  manufacturers. 

"  When  the  distillation  for  anthracene  oil  is  complete,  the  retort  may  be 
allowed  to  cool,  and  when  almost  cold  its  body  should  be  plunged  into  cold 
water.  This  produces  a  rapid  surface-cooling  and  shrinking  of  the  pitch 
from  the  glass,  which  may  then  be  broken  away  and  removed  by  gentle 
tapping,  leaving  the  cake  of  pitch  clean  and  ready  for  weighing." 

2.  SPECIAL  TESTS  FOR  TAR  CONSTITUENTS. — (a)  Benzol. — The  follow- 
ing method,  from  Allen,*  is  the  most  convenient  for  testing  benzol,  and 
is  reasonably  accurate.  One  hundred  cubic  centimetres  of  the  benzol  to  be 
tested  is  measured  in  an  accurately  graduated  cylinder,  and  poured  thence 
into  a  tubulated  retort,  of  such  a  size  as  to  be  capable  of  retaining  two  hun- 
dred cubic  centimetres,  or  eight  fluidounces,  when  placed  in  the  ordinary 
position  for  distillation.  A  delicate  thermometer  is  fitted  in  the  tubulure 
of  the  retort  by  a  cork,  so  that  it  may  be  vertical  and  the  lower  end  of  the 
bulb  be  three-eighths  of  an  inch  distance  from  the  bottom  of  the  retort.  The 
neck  of  the  retort  is  then  inserted  into  the  inner  tube  of  a  Liebig's  con- 
denser, and  pushed  down  as  far  as  it  will  go.  The  condenser  should  be  from 
fifteen  to  eighteen  inches  in  length,  and  well  supplied  with  cold  water.  The 
neck  of  the  retort  should  not  project  too  far  into  the  condenser ;  if  neces- 
sary it  should  be  cut  short.  No  cork  or  other  connection  is  necessary  be- 
tween the  retort-neck  and  condenser-tube.  Before  use,  the  tube  of  the  con- 
denser should  be  rinsed  with  a  little  of  the  sample,  and  allowed  to  drain,  or 
some  of  the  benzol  may  be  sprayed  through  it.  The  graduated  cylinder 

*  Commercial  Organic  Analysis,  3d  ed.,  vol.  ii.,  Part  ii.  p.  185. 


ANALYTICAL   TESTS   AND   METHODS.  383 

employed  for  measuring  out  the  sample  is  next  placed  under  the  farther  end 
of  the  condenser-tube  in  such  a  manner  as  to  catch  all  the  distillate,  while 
allowing  it  to  drop  freely.  The  retort  is  then  heated  by  the  naked  flame 
of  a  Bunsen  burner  (which  can  be  conveniently  placed  in  a  tin  basin  con- 
taining sand  or  sawdust,  in  order  to  absorb  the  benzol  in  the  event  of  the 
retort  cracking).  The  flame  should  be  small,  about  the  size  and  shape  of  a 
filbert,  and  when  the  distillation  of  the  benzol  commences  mustl)e~so  regu- 
lated that  the  condensed  liquid  shall  fall  rapidly  in  distinct  drops,  not  in  a 
trickle  or  a  continuous  stream. 

When  the  distillation  commences  the  flame  is  regulated,  if  necessary,  and 
the  rise  of  the  thermometer  carefully  watched.  The  moment  it  registers  a 
temperature  of  85°  C.  the  flame  is  extinguished.  Four  or  five  minutes  are 
allowed  for  the  liquid  in  the  condenser  to  drain  into  the  measuring  cylinder, 
and  then  the  volume  of  the  distillate  is  carefully  read  off  and  recorded.  The 
lamp  is  then  relighted  and  the  distillation  continued  till  the  thermometer 
rises  to  100°  C.,  when  the  gas  is  turned  oif  as  before,  and  the  volume  of  the 
distillate  read  off,  after  allowing  time  for  drainage.  The  residual  liquid  in 
the  retort  is  allowed  to  cool,  and  is  then  poured,  to  the  last  drop,  into  the 
measuring  cylinder.  A  deficiency  from  the  one  hundred  cubic  centimetres 
originally  taken  will  generally  be  observed.  The  difference  between  the 
collective  volume  after  distillation  and  that  of  the  original  sample  is  to  be 
added  to  the  measure  of  the  distillate  collected  at  each  temperature,  and  the 
corrected  volumes  reported  as  the  "  strength"  of  the  benzol  examined.  As 
a  matter  of  fact,  the  loss  of  volume  by  distillation  is  due  far  more  to  expul- 
sion of  acetylene  and  other  gases  than  to  actual  loss  of  benzol.  Lunge  in 
"  Coal-Tar  and  Ammonia"  (2d  edition,  1887)  gives  much  practical  informa- 
tion bearing  upon  this  subject,  which,  in  matters  relating  to  the  production 
and  sale  of  benzols,  etc.,  in  Europe,  has  received  considerable  attention. 

(6)  Phenols. — The  detection  of  phenol  is  in  many  cases  of  consider- 
able importance,  and  several  reactions  have  been  proposed ;  the  following 
are  taken  from  Allen,  who  has  personally  verified  them.  Upon  adding  a 
drop  of  a  dilute  aqueous  solution  of  phenol  to  a  small  quantity  of  a  solu- 
tion made  up  of  one  gramme  of  molybdic  acid  in  ten  cubic  centimetres  sul- 
phuric acid,  a  yellow-brown  coloration  is  produced  which  changes  to  a  per- 
manent purple  tint.  Many  substances  interfere  with  this  reaction  owing  to 
the  fact  that  it  depends  upon  the  reduction  of  the  molybdic  acid. 

Ferric  chloride  gives  a  fine  violet  color,  by  which  one  part  of  phenol  is 
detected  in  three  thousand  of  water.  Resorcin  and  hydroquinone  give  sim- 
ilar reactions.  Sodium  chloride,  nitre,  or  boric  acid  are  unobjectionable,  but 
most  mineral  and  organic  acids,  acetates,  borax,  sodium  phosphate,  glycerine, 
alcohol,  and  ether,  hinder  the  reaction.  If  an  aqueous  solution  of  phenol 
is  warmed  with  ammonic  hydrate  and  a  solution  of  sodium  hypochlorite  a 
permanent  deep-blue  color  is  obtained,  which  is  turned  red  upon  addition  of 
acids.  One  part  of  phenol  in  five  thousand  of  water  will  react  if  twenty 
cubic  centimetres  are  used,  weaker  solutions  also,  after  a  time.  A  modifi- 
cation of  the  above  is  to  add  to  fifty  cubic  centimetres  of  the  phenol  solu- 
tion five  cubic  centimetres  dilute  ammonia,  and  then  slowly,  fresh  and 
dilute  bromine-water,  when  a  fine  blue  tint  is  produced  which  is  permanent. 
Bromine  vapors  will  answer  instead  of  bromine- water. 

If  to  a  solution  of  phenol  a  drop  of  aniline  be  added,  and  then  a  solu- 
tion of  sodium  hypochlorite,  yellow  striae  are  produced  which  change  to 
blue.  This  is  very  delicate. 


384     INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

Upon  the  gradual  addition  of  bromine  to  a  solution  of  phenol  a  white 
turbidity  (mono-brom-phenol,  C6H4BrOH)  is  formed.  If  the  solution  is 
dilute  no  precipitate  occurs,  but  upon  the  addition  of  more  bromine,  di- 
brom-phenol  (C6H3B2OH)  is  formed ;  upon  further  addition  of  bromine  a 
very  bulky  precipitate  is  produced,  which  is  separated  as  the  insoluble  and 
characteristic  tri-brom-phenol  (C6H2Br3OH).  This  determination  of  phenol 
was  first  suggested  by  Landolt,  though  brought  to  perfection  and  used  as 
a  volumetric  method  by  Koppeschaar  (Z.  a.  Chemie,  xvi.  233). 

For  the  assay  of  carbolic  acid  the  specific  gravity  is  always  noted,  which 
ranges  between  1.04  and  1.065;  the  lower  figure  indicates  a  suspicious 
sample,  and  represents  light  tar  oils.  Water  is  estimated  by  agitating  the 
sample  with  half  its  volume  of  a  saturated  solution  of  salt,  the  loss  of 
volume  indicates  the  amount  of  water  originally  present.  To  ascertain  the 
quality  of  crude  carbolic  acid  and  probable  yield  of  crystallized  phenol,  the 
following  method  of  Lowe  (Allen,  Corn.  Org.  Anal.,  3d  ed.,  vol.  ii.,  Part  ii. 
p.  252)  is  used.  One  hundred  cubic  centimetres  are  distil ;ed,  and  the  dis- 
tillate collected  in  graduated  tubes.  Water  first  distils,  and  is  followed  by 
an  oily  fluid  ;  this  is  allowed  to  stand,  when  the  volume  of  water  is  read  off. 
If  the  oily  liquid  floats  on  the  water,  it  contains  light  oil  of  tar.  It  should 
be  heavier  than  water,  in  which  case  it  may  be  regarded  as  hydrated  acid 
containing  about  fifty  per  cent,  of  real  carbolic  acid.  The  next  portion  of 
the  distillate  consists  of  anhydrous  acid,  and  when  it  measures  62.5  per  cent, 
the  receiver  is  again  changed.  The  residue  in  the  retort  consists  wholly  of 
cresylic  acid  and  still  higher  homologues  of  carbolic  acid.  The  62.5  per 
cent,  of  anhydrous  acid  contains  variable  proportions  of  carbolic  and  cresylic 
acid.  These  may  be  approximately  determined  by  ascertaining  the  solidi- 
fying point,  which  should  be  between  15.5°  and  24°  C.,  and  by  making, 
with  known  proportions  of  carbolic  and  cresylic  acids,  a  standard  sample 
that  will  have  the  same  solidifying  point. 

(c)  Naphthalene. — The  assay  of  this  substance  generally  consists  in  sub- 
mitting about  twenty-five  grammes,  wrapped  in  several  folds  of  filter  or 
bibulous  paper,  to  pressure  in  a  copying-press  until  the  exudation  of  any 
oil  ceases,  when  the  cake  is  again  weighed,  and  if  desirable,  distilled  from 
a  small  retort.      Good  samples  should  not  distil  below  210°,  and  should 
yield  ninety  per  cent,  of  distillate  before  the  temperature  exceeds  225°  C. 
Upon  warming  sublimed  naphthalene  with  pure  sulphuric  acid  in  a  test- 
tube,  the  solution  should  remain  colorless.     If  one  per  cent,  of  impurity  is 
present,  a  decided  pinkish  tint  is  observed,  which  is  darker  the  greater  the 
amount.     The  determination  of  the  specific  gravity,  the  melting  point  (79° 
C.),  and  the  boiling  point  (216°  to  218°  C.)  are  made  by  the  usual  methods. 

(d)  Creosote  Oils. — The  characteristics  of  this  fraction  were  previously 
indicated.     The  specific  gravity  is  determined  either  by  the  bottle  or  hy- 
drometer ;  in  cases  where  the  sample  contains  much  naphthalene,  the  specific 
gravity  bottle  is  filled  and  the  contents  allowed  to  become  solid,  when  the 
stopper  is  worked  in.     A  sample  should  become  quite  clear  upon  warming 
to  about  38°  C.,  and  ought  not  become  turbid  till  cooled  to  32°  C.     The 
liquefying  point  is  determined  by  transferring  a  sample  of  the  oil  to  a  test- 
tube  immersing  a  thermometer,  and  warming  gently  till  it  becomes  liquid. 
The  point  of  turbidity  is  similarly  observed,  by  allowing  the  tube  to  cool 
spontaneously.     For  the  determination  of  the  naphthalene,  one  hundred 
grammes  are  chilled  to  45°  C.  in  a  small  beaker,  when  it  is  transferred  to  a 
cloth  filter,  placed  in  a  funnel  provided  with  means  for  cooling  to  4.5°  dur- 


ANALYTICAL  TESTS  AND  METHODS.  385 

ing  filtration.  The  filter  and  contents  are  removed  and  quickly  pressed 
between  bibulous  paper  in  a  copying-press,  when  the  cake  is  pressed  and 
weighed. 

(e)  Anthracene. — Commercial  anthracene  contains  a  very  variable  per- 
centage of  real  anthracene,  the  usual  proportions  being  from  thirty  to  forty 
per  cent.,  though  formerly  fifteen  per  cent,  was  common,  and  special  lots 
now  assay  over  eighty  per  cent.  The  value  of  anthracene  does- not  entirely 
depend  upon  the  amount  of  real  anthracene  alone,  but  also  upon  the  freedom 
from  objectionable  impurities.  In  testing  for  paraffine,  ten  grammes  of  the 
sample  are  taken  and  treated  with  two  hundred  grammes  of  concentrated 
sulphuric  acid,  heated  on  a  water-bath  for  about  ten  minutes,  or  until  the 
anthracene  is  dissolved,  when  any  paraffine  will  rise  to  the  surface  in  oily 
globules.  The  solution  is  now  poured  cautiously  into  a  tall  beaker  contain- 
ing five  hundred  cubic  centimetres  of  water,  stirred,  and  cooled,  when  the 
paraffine  rises  and  solidifies  on  the  surface ;  it  is  washed  with  water,  dried 
between  filter-paper,  and  weighed. 

By  the  conversion  of  anthracene  into  anthraquinone  the  most  satisfactory 
method  of  assaying  is  obtained.  (See  Allen,  Com.  Org.  Anal.,  3d  ed.,  vol.  ii., 
Part  ii,  p.  230.)  One  gramme  of  the  carefully  sampled  specimen  is  placed 
in  a  flask  holding  five  hundred  cubic  centimetres,  forty-five  cubic  centimetres 
of  the  very  strongest  glacial  acetic  acid  is  added,  and  an  inverted  condenser,  or 
long  glass  tube  adapted  to  the  flask.  The  liquid  is  then  brought  to  the  boiling 
point,  and,  while  boiling,  the  chromic  acid  solution  is  added  to  it  gradually, 
drop  by  drop,  by  means  of  a  tapped  funnel  passing  through  the  india-rubber 
stopper  in  the  flask,  or  inserted  in  the  top  of  the  vertical  condenser.  The 
chromic  acid  solution  is  prepared  by  dissolving  fifteen  grammes  of  crystallized 
chromic  anhydride  in  ten  cubic  centimetres  of  water  and  ten  of  glacial  acetic 
acid.  The  addition  of  the  oxidizing  agent  should  occupy  two  hours,  and 
the  contents  of  the  flask  should  be  kept  in  constant  ebullition  for  two  hours 
longer.  The  flask  is  then  left  for  twelve  hours,  when  the  contents  should 
be  diluted  with  four  hundred  cubic  centimetres  of  cold  water,  and  allowed 
to  rest  for  three  hours  longer.  The  precipitated  anthraquinone  is  filtered 
off,  and  well  washed  on  the  filter  with  cold  water,  and  with  a  boiling  one 
per  cent,  solution  of  caustic  soda  and  again  with  water.  The  anthraquinone 
is  rinsed  from  the  filter  into  a  small  dish,  the  water  evaporated  oif,  the 
residue  dried  at  100°  C.,  and  weighed.  The  following  after-treatment  is 
now  universally  employed  :  to  the  weighed  residue  ten  times  its  weight  of 
fuming  sulphuric  acid  is  added,  and  the  whole  heated  to  100°  C.  on  a  water- 
bath  for  ten  minutes,  after  which  it  is  left  in  a  damp  place  for  twelve  hours 
to  absorb  water,  when  two  hundred  cubic  centimetres  of  water  are  added ;  the 
precipitated  anthraquinone  filtered  off,  washed  with  water,  and  then  with 
one  hundred  cubic  centimetres  of  a  one  per  cent,  boiling  solution  of  caustic 
soda,  and  finally  with  boiling  water,  transferred  to  a  dish,  any  water  being 
evaporated  oif,  and  the  whole  dried  at  100°  C.  and  weighed.  The  weight 
of  the  anthraquinone  multiplied  by  the  factor,  .856,  gives  the  real  anthra- 
cene in  the  weight  of  the  sample. 

Anthracene  in  Tar  and  Pitch. — Nicol  (Z.  a.  Chemie,  xiv.  p.  318)  treats 
twenty  grammes  in  a  small  retort,  receiving  the  vapors  in  a  U  tube  kept  at 
200°  C.  The  more  volatile  products  do  not  condense,  but  the  anthracene 
and  other  hydrocarbons  do.  When  coking  has  taken  place,  the  process  is 
stopped,  and  the  neck  cut  off,  pounded,  and  the  powder  added  to  the  dis- 
tillate. The  whole  is  then  dissolved  in  glacial  acetic  acid  and  subjected  to 

25 


386     INDUSTRIES  BASED  UPON   DESTRUCTIVE  DISTILLATION. 

oxidation  with  chromic  acid  as  above  described.  Watson  Smith  does  not 
recommend  the  use  of  such  a  small  quantity  (twenty  grammes) ;  he  employs 
a  similar  method,  but  operates  upon,  at  least,  a  litre,  rejecting  the  portion 
distilling  just  before  the  coking.  The  anthracene  oil  is  well  mixed  and  an 
aliquot  part  employed. 

(/)  Pitch. — The  uses  to  which  this  residue  is  put  are  such  that  an 
elaborate  method  of  valuation  is  unnecessary,  although  the  method  for 
asphalt  is  applicable.  To  distinguish  between  the  two,  one  gramme  of  the 
sample  is  treated  with  five  cubic  centimetres  of  petroleum-spirit,  and  rapidly 
shaken.  The  mixture  is  filtered,  and  five  to  six  drops  of  the  filtrate  diluted 
to  five  cubic  centimetres  with  petroleum-spirit,  when  a  greenish  fluorescence 
will  be  noticed  in  the  case  of  tar.  Five  cubic  centimetres  of  rectified  spirit 
should  then  be  added,  the  mixture  shaken  and  allowed  to  stand.  The 
upper  layer  will  consist  of  strongly-colored  petroleum-spirit,  while  the 
lower  layer  of  alcohol  will  have  a  golden-yellow  color  if  coal-tar  is  present. 
In  the  case  of  mineral  asphalt,  the  alcohol  is  faintly  straw-yellow  and  often 
colorless. 

3.  VALUATION  OF  AMMONIA-LIQUOR. — Ordinarily,  the  Twaddle  hy- 
drometer is  employed  to  determine  the  strength  of  ammonia-liquor ;  every 
degree  of  the  instrument  is  taken  to  represent  such  an  amount  of  ammonia 
in  the  liquor  so  tested  that  one  gallon  will  require  two  ounces  of  concen- 
trated oil  of  vitriol  to  saturate  it ;  by  this  means  a  liquor  of  5°  Tw.  would 
be  known  as  "  Ten-ounce,"  4°  Tw.  would  be  "  Eight-ounce,"  etc.     These 
results  are  fallacious,  owing  to  the  presence  of  substances  which  cause  a 
false  strength  to  be  indicated. 

The  most  accurate  and  practical  method  consists  in  decomposing  ten 
cubic  centimetres  of  the  gas-liquor  to  be  assayed  in  a  flask  by  means  of  a 
solution  of  caustic  soda,  applying  heat,  and  collecting  the  vapors  of  am- 
monia evolved  in  a  known  quantity  of  normal  sulphuric  acid  contained  in 
another  flask  suitably  connected  ;  the  ammonia  vapors  neutralize  part  of 
this  acid,  and  that  which  remains  uncombined  is  exactly  neutralized  in  the 
presence  of  litmus  solution  with  normal  ammonia,  when  the  percentage  of 
ammonia  is  at  once  determined. 

4.  ANALYSIS  OF  ILLUMINATING  GAS. — The  analysis  of  illuminating 
gas  can  be  most  conveniently  carried  out  for  technical  purposes  with  the 
absorption  apparatus  devised  by  Hempel,  although  there  are  several  other 
forms  in  use  which  give  results  equally,  and  in  some  cases  more,  accurate. 
Hempel  employs,  for  measuring  the  gas  under  examination,  a  cylindrical 
tube,  similar  to  an  ordinary  burette,  graduated  to  one  hundred  cubic  centi- 
metres in  one-fifths,  and  mounted  in  an  iron  base.     This  burette  is  open  at 
the  top,  and  at  the  bottom  by  means  of  a  side-tube.     Another  tube  similar 
to  the  first,  but  without  graduations,  is  used  as  a  "  level-tube,"  and  is  con- 
nected to  the  burette  by  a  caoutchouc  tube  of  sufficient  length  that  the 
level-tube  can  be  raised  to  the  height  of  the  former  without  inconvenience. 
There  are  also  used  pipettes,  the  ordinary  form  of  which  consists  of  two 
glass   bulbs,  connected   by  means  of  capillary  tubes,   and  fastened  to  a 
board  provided  with  openings  to  accommodate  the  bulbs,  and  mounted  upon 
a  foot.     From  one  of  the  bulbs  a  siphon-shaped  tube  extends,  which  pro- 
jects a  short  distance  beyond  the  stand,  and  to  which  is  attached  a  caout- 
chouc tube  connecting  it  with  the  top  of  the  burette.     The  pipettes  contain 
the  several  liquids  and  solid  reagents  necessary  to  absorb  the  constituents 
of  the  gas.    Besides  the  simple  form  above  mentioned,  there  is  a  "  tubulated 


BIBLIOGRAPHY  AND  STATISTICS.  387 

absorption  pipette,"  so  made  as  to  allow  the  introduction  of  solids,  and 
which  can  be  readily  altered  to  a  pipette  for  the  generation  and  retention 
of  gases,  as  hydrogen  and  carbon  dioxide,  by  the  means  of  zinc  or  calcite 
respectively,  the  acid  required  for  the  liberation  of  the  gas  being  contained 
in  the  second  bulb. 

Another  form  is  the  "  compound  absorption  pipette,"  which  js  employed 
for  containing  the  reagents  readily  decomposed  upon  exposure  to  the  atmos- 
phere, or  which  give  off  noxious  vapors. 

The  method  of  operating  is  as  follows  :  The  level-tube,  previously  filled 
with  water,  is  raised  until  the  gas-burette  is  completely  filled,  when  it  is 
connected  by  means  of  a  caoutchouc  tube  to  the  "  aspirating-tube,"  or 
source  of  the  gas,  when  the  level-tube  is  lowered,  and  the  water  flows  out, 
causing  the  gas  to  take  its  place  in  the  burette ;  one  hundred  cubic  centi- 
metres are  obtained,  which  is  noticed  by  causing  the  water-level  in  each 
tube  to  coincide  with  the  100-cubic-centimetre  mark  on  the  lower  end  of 
the  burette.  The  absorption  of  the  several  constituents  takes  place  by  con- 
necting the  top  of  the  burette  to  the  end  of  the  siphon-shaped  tube  before 
mentioned,  when  the  level-tube  is  raised,  and  the  gas  is  forced  from  the 
burette  into  the  bulb  of  the  pipette,  the  absorbent  in  which  has  been  forced 
into  the  second  bulb.  When  all  the  gas  has  passed  over,  compressors  are 
applied  and  the  pipette  detached,  and  very  gently  agitated  from  two  to  five 
minutes,  in  which  time  the  absorption  will  be  complete ;  the  pipette  is  again 
attached,  the  level-tube  lowered,  when  the  remainder  of  the  gas  is  drawn 
back  to  the  burette,  which  is  closed,  the  water-level  in  each  brought  to  co- 
incide, and  the  reading  taken.  The  difference  between  this  reading  and  the 
original  volume  of  gas  taken  is  the  volume  absorbed.  One  constituent 
after  another  is  in  this  way  withdrawn  by  using  pipettes  containing  solu- 
tions having  affinity  for  the  several  gas  components,  as  indicated  below : 

Carbon  dioxide  (CO2).         Solution  of  potassic  hydrate. 

Ethylene  (C2H4).  }  Fuming  sulphuric  acid  or  bromine- water.    After  agitation,  the 

Propylene  (C3H6).  I  vapors  remaining  in  the  gas  are  removed  by  contact  with 

Butylene  (C4H8).    J  potassic  hydrate  solution. 

Benzene  vapor  (C6H6).         Fuming  nitric  acid  may  be  employed,  and  the  nitrous  vapor 

remaining   removed  by   agitation  in  the   potassic    hydrate 

pipette,  or  absolute  alcohol  is  used. 
Oxygen  (O).  An  alkaline  solution  of  pyrogallol,  or  phosphorus  chips  in  the 

presence  of  water,  can  be  used. 

Carbon  monoxide  ( CO) .  A  solution  of  cuprous  chloride  in  hydrochloric  acid  or  ammonia. 
Hydrogen  (H).  ^  Residue,  unabsorbed.  Constituents  determined  by  combustion, 

Methane  (CH^).  >•  mixing  the  residual  gas  with  air,  and  passing  the  mixture 

Nitrogen  (N).      J  over  palladium  sponge. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1867. — Chimie  Industrielle,  A.  Payen,  6me  ed.,  Paris. 

1870.— Das  Naphthalin  und  seine  Derivate,  M.  Ballo,  Braunschweig. 

1873. — Traite  des  Derives  de  la  Houille,  Girard  et  De  Laire,  Paris. 

1877. — Gasometrische  Methoden,  Robert  Bunsen,  2te  Auf.,  Braunschweig. 

1879.— Handbuch   der  Steinkohlengas  Beleuchtung,  2  Bde.,  3te  Auf.,  N.  H.  Schilling, 

Miinchen. 
1880.— Das  Anthracen  und  seine  Derivate,  G.  Auerbach,  2te  Auf.,  Braunschweig. 

Das  Holz  und  seine  Destillations-Producte,  Dr.  G.  Thenius,  Vienna. 
1883. — Die  Verwerthung  des  Holzes  auf  Chemischen  Wege,  J.  Bersch,  Vienna. 

Die  Meiler-  und  Retorten-Verkohlung,  Dr.  G.  Thenius,  Vienna. 
1885. — Conservirung  des  Holzes,  C.  Heinzerling,  Braunschweig. 


388    INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

1885.— Hand-book  of  Technical  Gas  Analysis,   O.   Winkler,  translated  by  G-.   Lunge, 

London. 

1886. — Die  Chemie  des  Steinkohlentheers,  2te  Auf.,  G.  Schultz,  2  Bde.,  Braunschweig. 
1887. — Manufacture  of  Gas  from  Tar,  Oil,  etc.,  W.  Burns,  London  and  New  York. 

Coal-tar  and  Ammonia,  2d  ed.,  G.  Lunge,  London. 

Die  technische  Verwerthung  des  Steinkohlentheers,  G.  Thenius,  Vienna. 

Diechemische  Technologic  der  Brenristoffe,  F.  Fischer,  Braunschweig. 
1889. — Ammoniak  and  Ammoniak  Praeparate,  R.  Arnold,  Berlin. 

Traitement  des  Eaux  Ammoniacales,  etc.,  Weill-Goetz  et  Desor,  Paris. 
1890. — Ammonia  and  Ammonia  Compounds,  Arnolc},  translated  by  Colman,  London. 

A  Practical  Treatise  on  the  Manufacture  of  Coal-Gas,  W.  Richards,  London. 

Dictionary  of  Applied  Chemistry,  T.  E.  Thorpe,  3  vols.,  London. 

L'Ammoniaque  dans  1'Industrie,  C.  Tellier.  Paris. 
1891. — Fabrikation  der  Leuchtgase,  G.  Thenius,  Leipzig. 

Die  Chemie  der  Steinkohlen,  F.  Muck,  2te  Auf.,  Leipzig. 

Engineering  Chemistry,  H.  J.  Phillips,  London. 

The  Chemistry  of  Illuminating  Gas,  Humphreys,  London. 

Carbolsaiire  und  Carbolsaiire  Praeparate,  H.  Kohler,  Berlin. 
1892. — Methods  of  Gas  Analysis,  W.  Hempel,  translated  by  L.  M.  Dennis,  New  York. 

Fuels,  Solid,  Liquid,  and  Gaseous,  Phillips,  London. 

Destructive  Distillation,  Edmund  J.  Mills,  4th  ed.,  London. 

Gas-works,  their  Construction,  etc.,  Hughes  and  Richards,  London. 

1894. Das  Conserviren  des  Holzes,  Louis  E.  Andres,  Wien. 

1895.— A  Treatise  on  the  Manufacture  of  Coke,  etc.,  John  Fulton,  Scranton,  Pa. 
1896.— La  distillation  des  Bois,  E.  Barillot,  Paris. 

The  Chemistry  of  Gas  Manufacture,  W.  J.  Butterfield,  Philadelphia. 

1899. The  Chemistry  of  Coke,  from  the  German  of  O.  Simmersbach,  W.  C.  Anderson, 

Glasgow. 

1900. — Die  Industrie  des  Steinkohlentheers  und  Ammoniak,  G.  Lunge,  3te  Auf.,  2  Bde., 
Braunschweig. 

STATISTICS. 

1.  OF  COAL  CARBONIZED  IN  GAS-MAKING.— Lunge  (Coal-Tar  and 
Ammonia,  2d  ed.,  pp.  12  and  13)  gives  several  estimates  of  the  amount  of 
coal  distilled  for  gas-making  in  Great  Britain  and  Ireland,  varying  from 
nine  million  to  twelve  million  tons  per  annum.     The  annual  distillation 
for  the  same  purpose  in  Germany  is  given  at  two  million  tons.     For  the 
United  States,  no  estimates  of  the  coal  used  in  gas-making  can  be  found. 

2.  OF  COAL  CARBONIZED  IN  COKE-OVENS. — According  to  "  Mineral 
Resources  of  the  United  States  for  1898,"  the  statistics  of  coke-production 
in  recent  years  were  as  follows : 

1896.  1897.  1898. 

Coal  used,  short  tons 18,694,422  20,907,319  25,249,570 

Coke  produced,  short  tons    .    .    .    11,788,773  13,288,984  16,047,209 

Average  percentage  yield     ...           63  63.5  63.6 

Value  of  coke  produced  .    .    .    .$21,660,729  $22,102,514  $25,586,699 

Of  this  amount,  two-thirds  is  produced  in  the  State  of  Pennsylvania, 
while  West  Virginia,  Alabama,  Virginia,  and  Colorado  follow  in  the  order 
named.  The  total  number  of  coke-ovens  in  the  United  States  at  the  end 
of  1898  was  48,447. 

The  present  annual  production  of  coke  in  Great  Britain  is  said  to  be 
21,000,000  tons,  requiring  the  carbonization  of  35,000,000  tons  of  coal. 

3.  BY-PRODUCT  COKE-OVENS  IN  THE  UNITED  STATES. — According  to 
"  Mineral  Resources  of  the  United  States  for  1898,"  there  were  at  the  end 
of  that  year  the  following  number  of  by-product  ovens  completed  and 
building : 

Completed 280  Semet-Solvay  ovens. 

180  Otto-Hoffmann  ovens. 

90  Newton-Chambers  ovens. 

3  Slocum  ovens. 

Building 600  Otto-Hoffmann  ovens. 


BIBLIOGRAPHY  AND   STATISTICS.  389 

4.  OF  COAL-TAR  PRODUCTION. — Gallois*  gives  the  following  as  the 
production  of  gas-tar  in  some  of  the  principal  European  countries  for  the 
year  1883  : 

Number  of  gas-works.  Coal-tar  produced. 

Great  Britain 452  450,000  tons. 

Germany 481  85,000     " 

France 601  75,000-" 

Belgium 50,000     " 

Holland 15,000     " 

Total 675,000    " 

Other  estimates  of  the  production  of  coal-tar  in  Great  Britain  and  Ire- 
land as  quoted  by  Lunge  vary  from  450,000  tons  to  750,000  tons.  That 
of  Mr.  Wilton,  of  the  Beckton  Tar-works,  putting  the  quantity  of  tar  dis- 
tilled in  1885  at  120,000,000  gallons,  averaging  twelve  pounds,  or  about 
643,000  tons,  would  seem  to  be  near  the  mean  of  these  estimates. 

The  same  author,  f  from  information  gathered  by  himself,  puts  the  pro- 
duction of  coal-tar  for  1886  in  Holland  at  20,000  to  22,000  tons,  in  Bel- 
gium at  about  30,000  tons,  and  in  the  United  States  at  120,000  tons,  of 
which  some  60,000  tons  are  distilled,  37,000  tons  are  employed  for  manu- 
facturing roofing-paper,  roof-coating,  etc.,  and  some  23,000  tons  are  used  up 
in  the  raw  state. 

4.  OF  COAL-TAR   DISTILLATION   PRODUCTS. — The   estimate  of  Mr. 
Wilton  of  the  coal-tar  production  of  the  United  Kingdom  for  1885  above 
quoted  includes  the  following  additional  details  : 

Ammoniacal  liquor  from  tar  alone  .    3, 600,000  gallons  =  1200  tons  of  sulphate. 

Carbolic  acid  (crude) 600,000       " 

Creosote  oil 21,600,000       " 

Of  this,  there  was  liquid  creosote  .  10,800,000       " 

Of  this,  there  were  creosote  salts 

(crude  naphthalene,  etc.)  .    .    .         56,620  tons. 

Corresponding  to  pure    naphtha- 
lene             25,310     " 

Green  oil 20,400,000  gallons. 

Benzol  and  toluol 1,500,000      " 

Solvent  naphtha 620,000      " 

Anthracene  (pure) 3,420  tons. 

Pitch 396,000     " 

The  German  importations  of  the  crude  coal-tar  and  coal-tar  products 
during  the  years  1892  and  1893  were : 

1892.  1893. 

Coal-tar,  metric  centners 368,904  397,217 

Value  in  marks 2,029,000  1,787,000 

Coal-tar  pitch,  metric  centners 113,078  877,689 

Value  in  marks 1,583,000  3,888,000 

Light  tar  oils,  metric  centners 56,833  74,726 

Value  in  marks 4,831,000  4,110,000 

Heavy  tar  oils,  metric  centners 29,552  14,819 

Value  in  marks 443,000  296,000 

5.  PRODUCTION  OF  SULPHATE  OF  AMMONIA. — The  production  for 
Great  Britain  and  Ireland  much  exceeds  that  of  all  other  countries  com- 


*  Lunge,  Coal-Tar  and  Ammonia,  2d  ed.,  p.  13. 
f  Ibid.,  p.  15. 


'390    INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

bined.     The  following  table  shows  the  amount  produced  in  recent  years 
and  the  sources  from  which  it  is  obtained : 


From  gas-works,  tons  ....               .    . 

1896. 
127,500 

1897. 
133,000 

1898. 
130,000 

1899. 
133,000 

From  iron-works,  tons     
From  shale-  works,  tons  

16,500 
38,000 

18,000 
37,000 

17,700 
37,300 

18,700 
37,300 

From  coke-  and  carbonizing-  works,  tons  . 

9,000 

10,000 

11,500 

13,000 

Total 191,000      198,000      196,500      202,000 

(Soc.  Chem.  Ind.  Journ.,  1900,  p.  87.) 

Lunge  states  (Coal-Tar  and  Ammonia,  2d  ed.,  p.  667)  that  Germany 
produces  about  10,000  tons  of  sulphate  of  ammonia  per  annum,  France 
produces  about  12,500  tons,  Holland  and  Belgium  about  3,000  tons,  and 
the  United  States  about  11,000  tons  per  annum. 


RAW   MATERIALS.  391 


CHAPTER   XII. 

THE   ARTIFICIAL   COLORING   MATTERS. 

I.  Raw  Materials. 

1.  HYDROCARBONS. — Benzene  Series. — In  the  manufacture  of  the  arti- 
ficial coloring  matters,  the  hydrocarbons  which  find  application  as  raw 
materials  are  limited  mainly  to  benzene,  naphthalene,  and  anthracene,  their 
homologues  and  derivatives ;  of  which,  probably,  benzene  is  the  most  im- 
portant. 

The  benzene  series  is  as  follows  : 

Boiling-point.  Specific  gravity. 

Benzene,  C6H6 80.4°  C.  .884  at  15°  C. 

Toluene,  C6H5.CH3 110°  C.  .869  at  15°  C. 

f  o-Xylene 142°  C.  .893  at  0°  C. 

Xylene,  C6H4.(CH3)J  m-Xylene 139°  C.  .881  at  0°  C. 

[  jo-Xylene 138°  C.  .880  at  0°  C. 

Pseudocumene,  \rTI  /PTT  x  f  169.5°  C.  .895  at  0°  C. 

Mesitylene,  f**&*\va*h \  165°  C.  .865  at  14°  C. 

Durene,  C6H2.(CH3)4.  (Fuses  at  79°-80°  C.) 192°  C.  

Pentamethylbenzene,  C6H.(CH3)5.  (Fuses  at  51.5°  C.)  .  231°  C.  

Hexamethylbenzene,  C6(CH8)6.  (Fuses  at  166°  C. )  .  .  265°  C,  

Of  which  only  the  first  three  are  employed  to  any  extent. 

Benzene  has  been  described  in  a  previous  chapter  (see  Tar  Distillation), 
but  for  the  manufacture  of  colors  an  explanation  is  necessary ;  the  name 
benzene,  chemically  speaking,  does  not  refer  to  the  light  fractions  obtained 
from  petroleum,  but  applies  solely  to  the  substance  distilled  from  coal-tar ; 
boiling  at  80.4°  to  81°  C.,  having  a  specific  gravity  of  .899°  at  0°,  with 
the  definite  composition  C6H6.  The  term  benzol,  on  the  other  hand,  is  not 
given  to  a  definite  compound,  but  to  a  mixture  of  benzene  with  variable 
quantities  of  toluene  and  xylene,  with  other  homologues  of  the  same  series. 
The  quantity  of  these  homologous  bodies  contained  have  an  influence  upon 
the  use  to  which  the  aniline  oil  obtained  (by  subsequent  treatment  of  the 
benzol)  can  be  put. 

The  pure  benzene,  free  from  the  high  boiling  homologues,  is  successively 
converted  through  several  processes  to  dimethylaniline,  which  is  the  base  of 
the  valuable  methyl-violets.  For  the  fuchsine  process,  benzol,  seventy-five 
per  cent,  of  which  distils  between  80°  and  100°  C.  (containing  toluene),  is  em- 
ployed, producing  aniline,  seventy-five  per  cent,  of  which  distils  between  180° 
and  190°  C.  High-boiling  benzol,  115°  to  120°  C.,  yields  aniline,  which 
is  the  starting-point  for  the  production  of  the  beautiful  series  of  xylidine 
scarlets ;  the  introduction,  however,  of  pure  xylene  has  served  to  displace 
the  above.  Allen  states  (Commercial  Organic  Analysis,  2d  ed.,  vol.  ii.  p. 
489),  "  Ninety  per  cent,  benzol  is  a  product  of  which  ninety  per  cent,  by 
volume  distils  before  the  thermometer  rises  above  100°  C.  A  good  sample 
should  not  begin  to  distil  under  80°  C.,  and  should  not  yield  more  than 
twenty  to  thirty  per  cent,  at  85°,  or  much  more  than  ninety  per  cent,  at 


392 


THE   ARTIFICIAL   COLOEING   MATTERS. 


100°  C.  It  should  wholly  distil  below  120°  C.  An  excessive  distillate— 
e.g.,  thirty-five  to  forty  per  cent,  at  85°  C. — indicates  a  larger  proportion  of 
carbon  bisulphide  or  light  hydrocarbons  than  is  desirable. 

"The  actual  percentage  composition  of  a  ninety  per  cent,  benzol  of 
good  quality  is  about  seventy  of  benzene,  twenty-four  of  toluene,  including 
a  little  xylene,  and  four  to  six  of  carbon  bisulphide  and  light  hydrocarbons. 
The  proportion  of  real  benzene  may  fall  as  low  as  sixty  or  rise  as  high  as 
seventy-five  per  cent.  Ninety  per  cent,  benzol  should  be  colorless  and  free 
from  opalescence." 

"Fifty  per  cent,  benzol,  often  called  50/90  benzol,  is  a  product  of  which 
fifty  per  cent,  by  volume  distils  over  at  a  temperature  not  exceeding  100°  C., 
and  forty  per  cent,  more  below  120°.  It  should  wholly  distil  below  130°." 

"  Thirty  per  cent,  benzol  is  a  product  of  which  thirty  per  cent,  distils 
below  100°,  about  sixty  per  cent,  more  passing  over  between  100°  and 
120°.  It  consists  chiefly  of  toluene  and  xylene,  with  small  proportions  of 
benzene,  cumene,  etc." 

The  following  table  from  Schultz  (Steinkohlentheers)  indicates  the  gen- 
eral properties  of  the  three  commercial  benzols  above  desc 
jected  to  distillation : 


described  when  sub- 


Thirty 
per  cent. 

Fifty 
per  cent. 

Ninety 
per  cent. 

To    8  ~>° 

0 

95 

90°  

2 

4 

70 

95°  

12 

26 

83 

100°  

30 

50 

90 

105°  

42 

62 

94 

110°  

70 

71 

97 

115°  

82 

82 

98 

120°  .... 

90 

90 

99 

The  theoretical  quantities  of  commercially  applicable  products  from 
benzol  are : 


For  100  parts,  157.6  parts  nitrobenzol. 
"      "       "       119.2     "     aniline. 
"      "       "       215.3     "     dinitrobenzol. 
"      "       "       155.1     "      dimethylaniline. 
"      diethylaniline. 


155.1 
191.0 


Toluene,  or  Meihylbenzene,  C6H5.CH3,  is  obtained  by  careful  distillation 
of  coal-tar  benzols,  and  can  be  obtained  from  the  balsam  of  tolu  and  other 
sources.  It  is  quite  similar  in  its  properties  to  benzene ;  fluid  at  ordinary 
temperatures,  and  when  pure  boils  between  110°  and  111°  C.  Specific 
gravity  .869.  It  is  employed  for  the  production  of  nitrotoluene,  toluidine, 
benzylchloride,  benzalchloride,  and  benzaldehyde, — the  base  of  a  valuable 
series  of  green  colors.  The  theoretical  yield  of  commercial  products  from 
toluene  are  as  follows  : 

For  100  parts,  148.9  parts  nitrotoluene. 
"      "       "       116.3     "      toluidine. 
"      "       "       115.3     "      benzaldehyde. 

Xykne,  or  Dimethylbenzene,  C6H4.(CH3)2,  exists  under  similar  conditions 


RAW   MATERIALS. 


393 


to  toluene,  and  is  found  in  coal-tar.  There  are  three  xylenes,  the  ortho-, 
meta-,  and  para-,  the  second  being  most  abundantly  obtained.  Owing  to 
the  slight  difference  between  their  respective  boiling-points,  a  commercial 
separation  by  distillation  is  practically  impossible. 

The  annexed  table  gives  the  nature  and  behavior  of  the  three  isomeric 
hydrocarbons  mentioned. 


Ortho-xylene. 

Meta-xylene. 

Para-xyiene. 

Meltir 
Boilin 
Specif 

•jjj 

If- 

S  * 
o 

Sulph 
Sulph 
Meltir 
pho< 
Meltir 
pha 

isr  point  .  . 

Fluid. 
141°  to  142°  C. 

Fluid. 
139°  C. 
.8668  at  19°  C. 
w-Toluic  acid,   melt- 
ing point  160°  C. 

I  Isophthalic  acid. 

Two  sulphonic  adds. 
Two  sulphonic  acids. 

(a)  34°  C.,  (b)  liquid, 
(a)  137°  C.,  (6)96°C. 

15°  C. 
137.5°  to  138°  C. 
.8621  at  19.5°  C. 
jo-Toluic  acid, 
melting  point 
178°  C. 

Terephthalic  acid 

No  change. 
Sulphonic  acid. 

26°  C. 
148°  C. 

cr-point 

c  gravity  . 

'  Dilute  nitric  acid 

Permanganate 
Chromic  acid   .    . 
uric  acid  (66°  Be.) 
uric  acid   (fuming) 
ig  point  of  the  sul- 
ihloride    .... 

o-Toluic  acid, 
melting  point 
102°  C, 
Phthalic  acid. 
Decomposed. 
Sulphonic  acid. 
Sulphonic  acid. 

52°  C. 
144°  C. 

ig  point  of  the  sul- 
rnide  

From  Schultz,  «  Steinkohlentheers. " 

Naphthalene  Series. — Naphthalene,  C10H8,  as  a  raw  material,  enters 
largely  into  the  production  of  the  extensive  series  of  azo-coloring  matters, 
and  for  such  use  it  is  converted  into  intermediary  products,  of  which  the 
alpha-  and  beta-naphthols  are  the  most  familiar.  The  occurrence,  proper- 
ties, and  production  of  naphthalene  are  referred  to  on  page  378. 

Methyl-naphthalene,  C10H7CH3. — Two  isomers  exist  in  coal-tar,  and  can 
be  separated  from  that  fraction  of  the  distillate,  boiling  at  from  220°  to  270°  C. 
The  first  of  these  is  a  liquid  boiling  at  243°  C. ;  specific  gravity  1.0287  at 
11.5°.  The  second  is  a  solid,  looking  like  naphthalene,  melting  at  32.5°  C. 
and  boiling  at  242°  C. 

Ethyl-naphthalene,  C12H12.  —  Two  isomers,  a-  and  £-,  are  known. 
a-Ethyl-naphthalene,  produced  from  a-brom-naphthalene  and  ethyl- 
bromide,  and  distilled  in  vacuum,  boils  at  from  257°  to  259.5°  C.  /9-Ethyl- 
naphthalene,  from  /3-brom-naphthalene,  ethyl  bromide,  and  sodium.  Boils 
at  from  250°  to  251°  C. 

Diphenyl,  C12H10,  has  been  found  in  coal-tar,  and  is  readily  obtained 
when  benzene  vapors  are  passed  through  a  red-hot  tube.  It  is  insoluble  in 
water,  soluble  in  hot  alcohol  and  in  ether.  It  forms  large  colorless  scales, 
melting  at  71°  C.  and  boiling  at  254°  C.  Oxidized  by  chromic  acid,  it 
yields  benzole  acid. 

Stilbene,  C14H12.— This  compound,  which  is  diphenylethylene  (C6H5.- 
CH  =  CH.C6H5),  is  formed  when  toluene  or  dibenzyl  is  led  over  heated 
lead  oxide.  It  crystallizes  in  colorless  scales,  melting  at  125°  C.  Forms 
the  basis  of  numerous  important  dyes. 

Anthracene  Series. — Anthracene,  C14Hlo,  reference  to  which  has  been 
made  in  the  previous  chapter,  is  employed  for  the  production  of  alizarine 
and  allied  bodies,  the  successful  introduction  of  which  caused  a  revolution 
in  the  processes  of  dyeing,  and  made  useless  for  the  time  great  areas  of  land 


394  THE   ARTIFICIAL   COLORING  MATTERS. 

which  were  devoted  to  the  culture  of  madder.  Anthracene,  as  it  occurs  in 
commerce,  is  rarely  pure,  being  made  up  of  a  very  large  number  of  hydro- 
carbons, several  of  which  have  not  been  investigated.  The  following  may 
be  mentioned : 

Methyl-anthracene,  C15H12,  closely  resembles  anthracene.  It  differs  from 
that  body  in  having  a  methyl  group  substituted  for  an  H  atom  of  one  of 
the  benzene  rings.  It  occurs  in  coal-tar  in  small  quantity,  and  owing  to 
the  high  boiling-point,  over  360°  C.,  it  is  found  in  the  anthracene,  Crys- 
tallizes in  pale-yellow  leaflets,  melting  at  199°  to  200°. 

Phenyl-anthracene,  C^H^,  is  formed  when  phenyl-anthranol  or  coeru- 
lei'n  is  heated  with  zinc-dust.  Slightly  soluble  in  hot  alcohol,  ether,  ben- 
zene, carbon  bisulphide,  and  chloroform,  and  upon  cooling,  crystallizes  from 
the  above  solvents  in  yellow  plates,  melting  at  1 52°  to  1 53°  C.  The  solutions 
have  a  blue  fluorescence. 

Fluorene,  or  Diphenylen-methane,  C13H10,  is  found  in  coal-tar,  and  can  be 
obtained  by  passing  diphenylmethane  through  a  combustion-tube  heated  to 
redness ;  it  can  also  be  obtained  by  distilling  diphenyleneketone  over  heated 
zinc-dust,  or  by  heating  the  same  substance  with  hydriodic  acid  aod  phos- 
phorus from  150°  to  160°.  Very  soluble  in  hot  alcohol,  less  in  the  cold ; 
crystallizes  in  colorless  plates  having  a  violet  fluorescence.  Melts  at  113°  C., 
boils  at  295°  C. 

Phenanthrene,  C14H10. — This  hydrocarbon  is  isomeric  with  anthracene,  is 
found  with  it,  and  forms  a  large  part  of,  the  last  fraction  of  coal-tar.  Com- 
pared with  anthracene,  the  melting  point  is  considerably  lower,  while  the 
boiling-points  are  somewhat  closer.  It  is  much  more  soluble  in  alcohol, 
by  which  means  a  separation  is  effected ;  the  low  melting  point  materially 
assisting.  Crystallizes  in  colorless,  shining  plates,  melting  at  100°  and  boil- 
ing at  340°,  insoluble  in  water,  but  soluble  in  fifty  parts  of  alcohol  in  the 
cold,  and  in  ten  parts  on  boiling ;  easily  soluble  in  ether  and  benzene.  It 
imparts  a  blue  fluorescence  when  dissolved.  When  oxidized,  phenanthren- 
quinone  is  formed.  Technically,  but  little  use  is  made  of  it,  being  chiefly 
employed  in  the  oil-baths  for  alkali  melts,  heating  autoclaves,  subliming 
phthalic  anhydride,  etc. 

Fluoranthene,  C15H10,  occurs  in  the  highest  boiling  tar  fractions ;  crystal- 
lizes in  needles ;  melts  at  109°. 

Pseudophenanthrenej  C16H12,  is  found  in  crude  anthracene,  and  crystal- 
lizes in  large  glistening  plates,  which  melt  at  115°.  Pyrene,  C16H10,  Retene, 
C18H18,  Chrysene,  C18H12,  and  Picene,  C22H14,  are  bodies  which  occur  in  the 
highest  fractions  with  fluoranthene,  and  cannot  be  classed  as  raw  materials, 
— no  technical  importance  being  attached  to  them. 

2.  HALOGEN  DERIVATIVES. — From  Benzene. — The  following  table  of 
the  halogen  derivatives  of  benzene  indicates  those  whose  constitution  is 
known.  They  are  produced  by  the  action  of  the  halogens  upon  the  hy- 
drocarbons directly,  or  through  the  action  of  the  halogen  compounds  of 
phosphorus  upon  phenols  and  aromatic  alcohols.  Two  classes  are  produced, 
substitution  and  addition  compounds.  The  former  occur  under  ordinary 
conditions,  while  the  latter  are  formed  when  the  reaction  takes  place  in 
direct  sunlight.  Of  the  two,  the  substitution  products  are  the  more  stable, 
the  addition  products  being  easily  decomposed. 

The  following  table  gives  the  formulas  of  the  several  halogen  deriva- 
tives of  benzene  and  the  boiling-points  of  the  more  important  of  the  several 
isomeric  compounds : 


RAW   MATERIALS. 


395 


Halogen  substitution  products  of  benzene. 

C6H6 
C6H5 

cX 

C6H3 
C6H2 
C6H 

^6 

Cl 

C12 
C13 
Cl 

ci5 
ci 

133° 
179° 
213° 
246° 
276° 
332° 

172° 
208° 
246° 

173° 
218° 

254° 

Br 
Br2 
Br3 
Br4 

Br5 

Br6 

154° 

224° 
276° 
329° 

219° 
278° 

219° 

Jh 

185° 

277° 

-*    i    '___ 

285°' 

: 

From  Toluene. — (1)  Benzyl-chloride  (Chlorbenzyl),  C6H5.CH2.C1,  results 
from  the  action  of  hydrochloric  acid  upon  benzyl  alcohol  (C6H5.CH2.OH), 
or  by  acting  on  boiling  toluene  with  chlorine,  this  method  being  the  one 
most  generally  used  ;  the  product  is  washed  with  water  containing  a  little 
alkali,  when  it  is  freed  from  impurities  by  distillation.  It  is  a  colorless  fluid, 
specific  gravity  1.113,  boils  at  179°,  insoluble  in  water,  but  soluble  in  alco- 
hol and  ether,  and  possesses  an  exceedingly  penetrating  odor,  acting  upon 
the  eyes  and  mucous  membrane  of  the  nose.  Technically,  it  finds  consid- 
erable application  in  the  color  industry. 

(2)  Benzol-chloride  (Benzidene  Dichloride),  C6H5.CH.C12. — Formed  when 
chlorine  acts  upon  boiling  benzyl-chloride,  or  when  phosphorus  penta-chloride 
acts  upon  benzaldehyde.     It  is  a  colorless  liquid,  having  ordinarily  but  little 
odor,  but  upon  the  application  of  heat  gives  off  a  vapor  producing  effects 
similar  to  the  preceding.     Boils  at  206°  to  207° ;  specific  gravity  at  16° 
1.295. 

(3)  Benzo-trichloride,  C6H5.C.C13,  is  obtained  by  acting  with  chlorine 
upon  boiling  toluene  until  no  further  increase  in  weight  takes  place,  when 
it  is  washed  in  water  containing  alkali,  dried,  and  distilled  in  a  vacuum. 
Boils  at  213°  to  214°;  specific  gravity  1.38  at  14°.     It  has  a  penetrating 
odor,  and  is  highly  refractive. 

Bromine  Derivatives  of  Xylene. — These  are  obtained  when  bromine  is 
allowed  to  act  upon  the  hydrocarbon  or  its  isomers,  or  upon  brominated 
compounds  of  the  same,  with  or  without  the  presence  of  iodine.  They 
find  no  application  industrially. 

Halogen  Derivatives  of  Naphthalene. — (1)  Naphthalene  Dichloride, 
C10H8C12,  is  a  liquid,  easily  decomposed ;  produced  as  an  addition  compound 
by  the  action  of  chlorine  gas  upon  naphthalene. 

(2)  Naphthalene  Tetrachloride,  C10H8.C14. — This  substance  is  manufac- 
tured in  large  quantities  by  passing  chlorine  gas  through  the  melted  hydro- 
carbon in  a  suitable  apparatus,  or  by  grinding  the  naphthalene  to  a  paste 
with  water  and  intimately  kneading  therein  sodium  or  potassium  chlorate, 
moulding  into  balls,  and  drying,  after  which  they  are  immersed  in  concen- 
trated hydrochloric  acid.     It  crystallizes  from  chloroform  in  large  rhom- 
bohedra,  melting  at  182°,  and  when  boiled  with  nitric  acid  is  converted  into 
phthalic  acid,  which  is  the  chief  product  obtained  from  it. 

(3)  a-Brom-naphihalene,  C10H7.Br. — Formed  by  the  direct  bromination 
of  the  hydrocarbon,  or  by  the  substitution  of  bromine  for  the  amido  group 
in  brom-a-naphthylamine.     It  is  a  liquid,  boiling  at  277°  ;  specific  gravity 
1.503  at  12°.     Insoluble  in  water,  soluble  in  alcohol  and  ether. 

(4)  p-Naphihyl-chloride,  C10H7.CH2C1,  is  formed  when  chlorine  acts  upon 
/3-methyl-naphthalene  at  a  temperature  of  240°  to  250°.     Melts  at  47°, 
boils  at  168°. 


396  THE   ARTIFICIAL   COLORING   MATTERS. 

(5)  p-Naphthyl-bromide,  C10H7.CH2Br. — Formed  when  the  vapor  of 
bromine  with  CO2  gas  is  brought  in  contact  with  /9-methyl-naphthalene, 
heated  to  240°.  Crystallizes  from  alcohol  in  white  plates,  which  melt  at 
56°. 

Anthracene  Derivatives. — (1)  Monochlor-anthracene,  C14H9.C1. — When 
dichlor-anthracene  is  heated  hydrochloric  acid  is  evolved,  having  the  mono- 
chlor  derivative.  Soluble  in  alcohol,  ether,  carbon  bisulphide,  and  benzene. 
Crystallizes  in  yellow  needles,  melting  at  103°. 

(2)  Divhlor-anthracene,  C14H8.C12,  is  produced  when  anthracene  is  al- 
lowed to  remain  in  contact  with  chlorine,  or  when  the  monochlor  derivative 
is  similarly  treated,  being  maintained  at  a  temperature  of  100°.     Freely 
soluble  in  benzene,  but  not  readily  in  alcohol  or  ether.     Forms  beautiful 
yellow  lustrous  needles,  which  melt  at  209°.     Treated  with  sulphuric  acid 
at  a  low  temperature,  dichlor-anthracene-sulphonic  acid  occurs  in  solution ; 
this,  when  heated,  yields  sulphurous  acid,  hydrochloric  acid,  and  the  an- 
thraquinone-disulphonic  acid,  which  is  the  immediate  base  of  the  artificial 
alizarine. 

(3)  Dibrom-anthracene,  C14HgBr2. — Upon  agitating  bromine  with  a  so- 
lution of  anthracene  in  carbon  bisulphide  this  derivative  is  formed.     Diffi- 
cultly soluble  in  alcohol,  ether,  and  benzene ;  hot  toluene  or  xylene  answer 
best.     Crystallizes  in  gold-yellow  needles,  melting  at  221°,  and  subliming 
without  decomposition. 

3.  NITRO-  DERIVATIVES. — By  the  action  of  nitric  acid  upon  the  hydro- 
carbons nitro-  derivatives  are  obtained,  and  one  of  the  most  important  of 
these — nitrobenzene — is  manufactured  in  very  large  quantities  for  use  in 
the  color  industry. 

(1)  Nitrobenzene,  C6H5.NO2,  was  discovered  by  Mitscherlich,  who  ob- 
tained it  by  heating  benzene  or  benzoic  acid  with  fuming  nitric  acid.     It 
was  first  brought  into  trade,  bearing  the  name  "  oil  of  mirbane"  (artificial 
oil  of  bitter  almonds),  by  Collas,  and  in  1847  a  patent  for  its  manufacture 
from  coal-tar  was  granted  to  Mansfield.     It  is  obtained  by  adding  a  cooled 
mixture  of  concentrated  sulphuric  and  nitric  acid  (150  : 100)  to  the  hydro- 
carbon and  agitating,  taking  care  that  the  temperature  does  not  go  above 
50°  C.     After  the  addition  of  the  acid  is  complete,  heat  is  applied,  and  it  is 
again  agitated.     The  oily  layer  is  removed,  washed  with  dilute  alkali,  dried, 
and  distilled.     Nitrobenzene,  when  pure,  is  a  pale-yellow  fluid,  strongly  re- 
fractive, having  the  odor  of  bitter  almonds,  and  a  sweet,  though  burning, 
taste.     Specific  gravity  1.208  at  15°  ;  boils  at  206°  to  207°,  and  when  the 
temperature  is  reduced  it  crystallizes  in  large  needles,  which  melt  at  -j-3°. 
Nearly  insoluble  in  water,  though  with  alcohol,  ether,  and  benzene  it  is 
readily  soluble.     It  is  exceedingly  stable,  and  even  at  a  boiling  temperature 
it  is  not  acted  upon  by  either  bromine  or  chlorine.     It  is  poisonous,  and, 
according  to  Roscoe  and  Schorlemmer  (vol.  iii.  pt.  iii.),  "especially  when  the 
vapor  is  inhaled ;  it  produces  a  burning  sensation  in  the  mouth,  nausea  and 
giddiness,  also  cyanosis  of  the  lips  and  face,  and  in  serious  cases,  which 
frequently  end  fatally,  symptoms  of  a  general  depression." 

(2)  Dinitrobznzene,  C6H4(NO2)2. — Three  isomers  of  this  derivative  exist, 
being  obtained  when  benzene  is  nitrated  with  the  concentrated  acids,  as  in 
the  preceding  case,  but  instead  of  being  cooled  is  boiled  for  a  short  time, 
when  the  product  is  washed  with  water,  pressed,  dissolved  in  alcohol,  from 
which  the  meta-nitro  body  crystallizes,  followed  upon  standing  by  the  para- 
nitro  compound.     Upon  distilling  the  alcohol  remaining  in  the  mother- 


RAW   MATERIALS.  397 

liquors  from  the  para-  compound  a  further  yield  of  the  meta-  body  is  ob- 
tained, finally  the  ortho-dinitrobenzene,  which  occurs  in  small  quantity, 
crystallizes,  and  is  purified  by  treatment  with  acetic  acid,  from  which  it  is 
deposited  in  needles,  having  a  melting  point  of  117.9°.  The  para-  com- 
pound occurs  in  monoclinic  needles,  melting  at  172°,  and  subliming.  The 
meta-  compound  finds  technical  application  in  the  production  of_chrysoidine 
and  Bismark  brown,  and  is  manufactured  on  a  large  scale  by  adding  a 
mixture  of  one  hundred  kilos,  nitric  acid  (specific  gravity  1.38)  and  one 
hundred  and  fifty-six  kilos,  sulphuric  acid  (specific  gravity  1.84)  to  one 
hundred  kilos,  of  benzene.  When  the  reaction  is  over,  a  separation  of  the 
acids  (which  can  be  used  again)  from  the  product  occurs ;  commercially,  the 
product  is  washed  with  warm  and  cold  water,  further  purification  being 
unnecessary.  It  crystallizes  in  needles  or  rhombic  tables,  which  melt  at 
89.8°,  boiling  at  297°.  Difficultly  soluble  in  warm  water,  easily  in  ether 
and  alcohol. 

Nitrotoluene. — (1)  Nitrotoluene,  C6H4(NO2)CH3,  occurs  in  three  isomers. 
The  ortho-  derivative  is  a  liquid  boiling  at  223°,  and  at  23.5°  has  a  specific 
gravity  of  1.162.  Does  not  become  solid  at  20°.  The  meta-  derivative 
melts  at  16°,  boils  at  230°  to  231°.  Specific  gravity  at  22°  1.168.  Para- 
nitrotoluene,  melting  point  54°,  distilling  unchanged  at  236°,  occurs  in 
colorless  prisms.  Nitrotoluene,  consisting  more  or  less  of  a  mixture  of  the 
above,  is  manufactured  in  large  quantities  and  in  the  same  manner  as  for 
nitrobenzene.  Ten  parts  of  toluene  are  mixed,  and  continually  agitated 
with  eleven  parts  of  nitric  acid  (specific  gravity  1.22)  and  one  part  sul- 
phuric acid  (specific  gravity  1.33).  The  product  is  treated  with  water,  and 
afterwards  with  caustic  alkali ;  distilled  to  remove  uncombined  toluene,  and 
finally  distilled  with  superheated  steam.  When  fractionated,  that  part  pass- 
ing over  at  230°  yields,  when  purified,  para-nitrotoluene,  and  is  employed 
in  the  production  of  toluidine,  tolidine,  and  fuchsine.  The  fraction  between 
222°  and  223°  is  nearly  all  ortho-nitrotoluene. 

(2)  DinitrotolueneSj  C6H3(NO2)2.CH3. — «-  or  ordinary  dinitrotoluene  is 
produced  when  toluene  is  added  to  a  mixture  of  fuming  nitric  and  sul- 
phuric acids  and  boiled ;  ortho-nitrotoluene  is  employed  for  the  manufac- 
ture also.  Crystallizes  in  needles,  which  melt  at  70.5°  ;  insoluble  in  water, 
little  soluble  in  alcohol,  ether,  or  carbon  bisulphide.  /?-dinitrotoluene, 
isomeric  with  the  above,  is  produced  under  similar  conditions  ;  or  it  can  be 
made  by  replacing  the  amido  group  of  dinitroparatoluidine  with  hydrogen. 
Crystallizes  in  golden-yellow  needles;  melting  point  61.5°. 

Trinitrotoluene,  C6H2.(NO2)3CH3. — Produced  by  the  action  of  nitric  and 
sulphuric  acids  upon  toluene,  or  dinotrotoluene,  and  heating  for  several 
days.  a-Trinitrotoluene  is  soluble  in  alcohol,  crystallizing  from  it  in  beau- 
tiful needles,  which  melt  at  82°.  /9-Trinitrotoluene  crystallizes  from  acetone 
in  transparent  prisms,  which  melt  at  112°,  while  from  alcohol  it  forms 
plates  or  flat  white  needles.  ^-Trinitrotoluene  is  deposited  from  acetone  in 
small  hexagonal  crystals,  melting  at  104°. 

Mononitronaphthalene,  C10H7.NO2. — Two  isomers  exist ;  the  «-  compound 
is  produced  when  ten  parts  naphthalene,  eight  parts  nitric  acid  (specific  gravity 
1.4),  and  ten  parts  sulphuric  acid  (specific  gravity  1.84)  are  combined  in  a 
nitrobenzene  apparatus.  The  naphthalene  is  added  in  small  portions  and 
continually  stirred.  The  product  is  washed  with  water,  and  freed  from  acid 
by  treatment  with  alkali.  Insoluble  in  water,  easily  in  benzene,  carbon 
bisulphide,  ether,  and  alcohol.  Crystallizing  in  yellow  needles,  melting  at 


398  THE   ARTIFICIAL   COLORING  MATTERS. 

61°,  boiling  at  304°.  The  £-  compound  is  produced  when  r-nitronaph- 
thylamine  is  melted  with  nitrate  of  potassa.  Soluble  in  alcohol,  ether,  or 
glacial  acetic  acid.  Crystallizes  in  yellow  needles  ;  melts  at  79°. 

a-Dinitronaphthalene,  C10H6(NO2)2,  obtained  in  a  similar  manner  to  the 
above.  Difficultly  soluble  in  cold,  easily  in  warm,  benzol.  From  glacial 
acetic  acid  it  crystallizes  in  needles,  melting  at  217°.  /?-Dinitronaph- 
thalene,  isomeric  with  the  above,  crystallizes  in  rhombic  plates,  melting 
at  170°. 

4.  AMINE  DERIVATIVES. — The  amine  derivatives  of  benzene,  toluene, 
and  xylene  can  be  regarded  as  forming  one  of  the  most  important  groups  of 
raw  materials  from  which  are  obtained  the  basic  coloring  matters,  all  of  which 
contain  nitrogen.  The  structure  of  the  amines  can  readily  be  seen  if  we  em- 
ploy ammonia,  NH3,  as  the  type ;  in  this  case  there  are  three  atoms  of  hydro- 
.gen.  If  one  of  these  be  replaced  by  an  organic  radical  a  primary  amine  is 
produced ;  if  two,  or  all  three  are  replaced,  a  secondary  or  tertiary  amine 
respectively  is  formed. 

Aniline,  or  Amido-benzene,  C6H5.NH2. — This  substance  was  discovered 
by  Unverdorben  in  1826,  who  noticed  its  property  of  combining  with  acids 
to  form  salts.  Eunge,  subsequently,  experimenting  upon  coal-tar,  found  a 
volatile  substance  which,  when  treated  with  a  solution  of  bleaching-powder, 
produced  a  blue  coloration,  giving  rise  to  the  name  kyanol.  It  was  he  who 
noticed  that  when  a  drop  of  the  "  nitrate  of  kyanol"  was  brought  in  contact 
with  dried  cupric  chloride,  a  black  spot  was  formed.  Fritsche,  later,  exam- 
ined the  distillation  products  of  indigo,  and  found  a  body  to  which  he  gave 
the  name  aniline.  Aniline  was  formerly  obtained  in  large  quantities  by  re- 
ducing the  nitrobenzene  with  iron  filings  or  scrapings  and  acetic  acid,  but 
now  it  is  wholly  produced  with  hydrochloric  acid.  The  following  reaction 
showing  the  change  that  occurs  : 

(Nitrobenzene.) 

C6H5.NO2  +  3Fe  +  6HC1  = 

(Aniline.) 

C6H5.NH2  +  3FeCl2  +  2H2O. 

The  quantity  of  acid  represented  by  the  above  equation  is  more  than 
sufficient  for  the  purpose,  from -the  fact  that  ferrous  chloride  (FeCl2),  a 
reducing  agent  itself,  will  act  in  the  reduction  of  a  further  quantity  of 
nitrobenzene : 

C6H5.NO2  +  6FeCl2  +  6HC1  = 
C6H5.NH2  +  3Fe2Cl6+H20. 

Aniline  is  a  liquid,  fluid  at  ordinary  temperatures,  but  when  frozen  melts 
at — 8°;  boils  at  182°  when  pure;  specific  gravity  1.036  ;  colorless  when 
freshly  distilled,  but  becomes  reddish-brown  upon  exposure  to  light  and  air ; 
impurities  hasten  discoloration.  Soluble  in  alcohol,  ether,  and  benzene  in 
all  proportions  ;  in  water  it  is  soluble  to  a  slight  extent,  one  hundred  parts 
of  water  dissolving  three  parts  aniline,  while  it,  in  turn,  dissolves  water  to 
the  extent  of  five  per  cent. 

Aniline  forms  a  series  of  well-crystallized  salts,  among  which  are  the 
hydrochloride, — C6H7.N.C1H, — known  as  "  aniline  salt,"  largely  employed 
in  the  production  of  black  upon  cotton ;  and  the  sulphate, — (C6H7N)2H2SO4, 
- — of  considerable  importance. 

Methylaniline,  C6H5.NH(CH3),  is  obtained  by  heating  aniline  hydro- 


RAW  MATERIALS.  399 

chloride  or  a  mixture  of  aniline  and  hydrochloric  acid  with  rather  more 
than  a  molecule  of  methyl  alcohol  at  200°  C.  The  product  is  then  con- 
verted into  sulphate  and  the  easily  soluble  sulphate  of  methylaniline 
separated  from  the  sparingly  soluble  aniline  sulphate.  The  sulphate  is 
decomposed  by  an  alkali  and  the  free  base  obtained  by  distillation.  The 
commercial  product  contains  from  ninety  to  ninety-five  per  cent,  of  pure 
methylaniline.  It  is  a  colorless  oil,  boiling  at  192°  C.,  and  lias  a  specific 
gravity  0.976  at  15°  C. 

Dimethylaniline,  C6H5.N(CH3)2,  is  obtained  by  heating  a  mixture  of 
aniline  (seventy-five  parts),  aniline  hydrochloride  (twenty-five  parts),  and 
methyl  alcohol,  free  from  acetone  (seventy-five  parts),  in  a  cast-iron  auto- 
clave at  from  230°  to  270°  C.  The  product  is  rectified.  The  yield  is  about 
one  hundred  and  twenty  parts  from  the  above  proportions.  It  is  a  color- 
less oil,  boiling  at  192°  C.,  and  specific  gravity  0.96  at  15°  C.  Solidifies 
at  +5°  C.  to  a  crystalline  solid.  The  commercial  product  is  usually 
nearly  pure. 

Nitraniline,  C6H4(NO2)NH2. — Both  the  m-  and  the  j9-nitraniline  are 
used  technically.  The  former  is  made  by  the  partial  reduction  of  dinitro- 
benzene ;  the  latter  from  acetanilid,  which  is  nitrated  and  then  freed  from 
the  acetyl  group  by  treatment  with  steam. 

Toluidine,  or  Amido- toluene,  C6H4(CH3)NH2,  occurs  in  three  isomers, 
according  to  the  extent  to  which  the  nitration  of  the  toluene  was  originally 
carried.  Ortho-toluidine  is  produced  by  the  reduction  of  ortho-nitro- toluene, 
by  the  same  means  as  was  applied  in  the  case  of  aniline.  It  is  a  fluid,  color- 
less at  first,  but  becoming  brown  upon  exposure.  Specific  gravity  1.000  at 
16°,  boiling  point  197° ;  soluble  to  a  slight  extent  in  water  (2  :,100)  and  in 
alcohol. 

Meta-toluidine,  occurring  similarly  to  the  preceding,  is  a  liquid.  Specific 
gravity  .998,  boiling  at  197°,  little  soluble  in  water,  but  freely  in  alcohol 
and  ether. 

Para-toluidine  is  obtained  in  the  form  of  large  colorless  leaflets,  crystal- 
lizing from  alcohol.  Specific  gravity  1.0017,  melting  point  45°,  and  boil- 
ing at  198°  ;  slightly  soluble .  in  water,  readily  in  alcohol  and  ether.  Com- 
mercial toluidine  consists  chiefly  of  a  mixture  of  the  ortho-  and  para-  bodies, 
and  containing  very  little  aniline ;  it  is  of  considerable  importance  in  the 
color  industry. 

Xylidine,  or  Amido-xylene,  C6H3(CH3)2.NH2,  homologous  with  aniline 
and  toluidine,  is  produced  from  xylene,  as  aniline  is  from  benzene, — nitration 
followed  by  reduction.  Six  isomers  are  obtainable,  but  the  xylidine  indus- 
trially employed  consists  of  a  mixture  of  five.  At  ordinary  temperature  it 
is  a  liquid,  specific  gravity  .9184  at  25°,  boiling-point  212°.  From  this  de- 
rivative the  beautiful  series  of  xylidine  scarlets  are  produced. 

Naphthylamine,  C10H7.NH2. — Two  isomers  exist.  For  a-Naphthylamine, 
naphthalene  is  converted  into  the  nitro-  derivative  as  has  been  described,  and 
equal  parts  of  this  body  and  water  are  heated  to  80°,  incorporated  with  an 
equal  part  of  iron  filings,  and  reduced  with  hydrochloric  acid.  The  product 
is  distilled  with  lime,  and  finally  rectified  by  further  distillation.  Nearly 
insoluble  in  water,  soluble  in  alcohol  and  ether ;  crystallizes  in  colorless 
needles  or  prisms,  which  melt  at  50°  and  boil  at  300°.  Upon  contact  with 
the  air  it  acquires  a  red  color,  and  oxidizing  agents  cause  a  blue  precipitate 
to  form  in  solutions  of  its  salts.  It  finds  extensive  application  in  the  prep- 
aration of  several  colors  of  importance.  /5-Naphthylamine  is  produced  when 


400  THE   ARTIFICIAL   COLORING  MATTERS. 

gaseous  ammonia  combines  with  /9-naphthol  in  the  fused  state  ;  commercially 
it  is  obtained  by  the  action  of  ammonio-chloride  of  calcium,  or  ammonio- 
chloride  of  zinc,  upon  the  same  body,  assisted  by  heat,  and  the  subsequent 
separation  of  by-products.  It  occurs  in  white  or  pearly  leaflets,  odorless, 
difficultly  soluble  in  cold,  freely  in  hot,  water,  and  in  alcohol  and  ether. 
Melting  point  112°,  boiling  at  294°.  Unlike  the  a-naphthylamine,  it  is 
not  acted  upon  by  oxidizing  agents. 

Phenylenediamine,  C6H4(NH2)2.  —  Both  the  m-  and  the  p-  compounds  are 
used  in  practice.  The  former  is  obtained  by  the  reduction  of  m-dinitro- 
benzene  with  iron  and  hydrochloric  acid  ;  the  latter  by  the  reduction  of 
amidoazobenzene  with  zinc-dust  in  aqueous  solution. 

O  H  NH 

Benzidine  (diamido-diphenyl),  |  °  .  —  This  base  is  manufactured 


on  a  large  scale  as  the  basis  of  the  substantive  cotton  dyes  (see  p.  418). 
For  its  preparation  nitrobenzene  is  reduced  by  zinc-dust  and  caustic  soda 
in  the  presence  of  alcohol.  The  hydrazobenzene  so  obtained  is  heated  in 
the  presence  of  hydrochloric  acid  to  boiling  and  the  benzidine  precipitated 
from  the  solution  by  the  addition  of  sulphuric  acid.  It  forms  a  grayish- 
white  crystalline  solid,  fusing  at  122°  C.,  and  rather  difficultly  soluble  in 
Water. 

Diphenylamine,  (C6Fr5)2NH,  is  made  on  a  large  scale  by  heating  aniline 
with  aniline  chlorhydrate  in  autoclaves  to  between  220°  and  230°.  It 
forms  a  white  or  slightly  yellowish  solid,  melting  at  54°,  and  has  a  pleasant 
odor  of  flowers. 

5.  PHENOL  DERIVATIVES'.  —  Phenol,  C6H5OH.  —  The  occurrence  of  this 
body  has  been  mentioned  under  tar  products,  page  359.  It  crystallizes  in 
needles,  which  have  the  well-known  odor  of  "  carbolic  acid."  Specific  gravity 
1.08,  and  melting  at  37.5°,  boiling  at  132°  to  133°  ;  soluble  in  water  (1  :  15) 
and  readily  in  alkalies,  alcohol,  and  ether.  It  finds  extensive  application  in 
the  color  and  other  industries,  large  quantities  being  consumed  in  the  manu- 
facture of  picric  acid. 

Resordn,  or  Dioxy-benzene,  C6H4(OH)2,  is  obtained  from  benzene  by 
fusing  the  sodium  sulphonate  of  the  latter  with  caustic  soda.  (See  page  407.) 
Occurs  in  sweetish,  colorless  crystals,  which,  however,  eventually  become 
dark  colored,  melting  point  110°,  boiling-point,  271°;  readily  soluble  in 
water,  alcohol,  and  ether.  Specific  gravity  1.28. 

Pyrogallol,  or  Trioxy-benzene,  C6H3(OH)3,  is  readily  obtained  from  gallic 
or  tannic  acid  when  the  same  are  heated  to  210°  to  220°.  It  can  be  obtained 
from  benzene,  but  the  above  method  is  more  generally  adopted.  Processes 
for  its  manufacture  are  detailed  on  page  408.  Pyrogallol  occurs  in  white 
leaflets,  which  melt  at  115°  and  boil  at  210°  ;  soluble  in  water,  alcohol,  and 
ether. 

Naphthols,  C10H7.OH.  —  The  two  derivatives  of  naphthalene,  a-  and 
/9-naphthol,  find  extensive  application  in  the  manufacture  of  artificial  color- 
ing matters.  They  are  prepared  from  the  two  isomeric  naphthalene  sul- 
phonic  acids,  «  and  /?,  which  are  discussed  under  Processes,  page  393. 
a-Naphthol  occurs  as  lustrous  needles,  which  melt  at  94°,  boil  at  278°  to 
280°;  specific  gravity  1.224;  sparingly  soluble  in  hot,  insoluble  in  cold, 
water  ;  soluble  in  alcohol,  ether,  benzene,  and  in  solution  of  caustic  alka- 
lies. /9-Naphthol  occurs  in  leaflets,  melting  at  122°,  boiling  from  285°  to 
290°  ;  solubility  same  as  for  the  preceding.  Allen  (Commercial  Organic 


EAW   MATERIALS. 


401 


Analysis,  2d  ed.,  vol.  ii.  p.  511)  gives  the  following  table  of  the  distin- 
guishing characteristics  of  the  two  naphthols  : 


a-Naphthol. 


0-Naphthol. 


Crystallizes  in  small  monoclinic  needles. 
Meltir.g  point  94°  ;  boils  at  278°  to  280°. 
Faint  odor,  resembling  phenol. 
Volatilizes  readily  with  vapor  of  water. 
Aqueous    solution    becomes    dark    violet, 

changing    to   reddish-brown   on   adding 

solution  of  bleaching-powder. 
Aqueous   solution  becomes  red,  and  then 

violet,  on  adding  ferric  chloride. 


Crystallizes  in  rhombic  laminae. 
Melting  point  122°;  boils  at  2&5°~to  290°. 
Almost  odorless. 

Scarcely  volatile  with  vapor  of  water. 
Aqueous  solution  colored  pale  yellow  by 
solution  of  bleaching-powder. 

Aqueous  solution  becomes   pale  green  on 
adding  ferric  chloride. 


6.  STJLPHO-  ACIDS. — This  group  constitutes  an  interesting  and  techni- 
cally valuable  series  of  bodies,  which  are  obtained  by  the  action  of  concen- 
trated sulphuric  acid  upon  the  hydrocarbons,  or  upon  coloring  matters 
already  formed. 

(1)  Benzene-sulphonic  AM,  C6H5.SO3H,  is  readily  obtained  by  heating 
two  parts  benzene  with  three  parts  sulphuric  acid  to  100°  C.,  diluting  with 
water,  saturating  with  carbonate  of  lead,  and  decomposing  with  sulphuric 
acid  to  liberate  the  sulphonic  acid.    The  acid  is  soluble  in  water  and  alcohol, 
and  crystallizes  in  small  plates. 

(2)  Benzene-disulphonic  Acid,  C6H4(SO3H)2,  is  produced  when  benzene  is 
heated  with  fuming  sulphuric  acid  to  275°.     Employed  in  the  production 
of  resorcin. 

(3)  Toluene-sulphonic  Acid,  C6H4(CH3)SO3H. — No  importance. 

(4)  Naphthalene-sulphonic  Acids,   C10H7.SO3H. — Two   isomeric   bodies 
are  obtained  when  naphthalene  is  submitted  to  the  action  of  sulphuric  acid. 
At  temperatures  ranging  from  80°  to  100°  the  a-derivative  is  largely  ob- 
tained, and  at  temperatures  from  160°  to  170°  the  /^-derivative  is  produced. 
Their  separation  is  based  upon  the  different  degrees  of  solubility  of  the 
lead  salts  upon  concentrating  their  aqueous  solutions,  a-naphthalene  sul- 
phonic acid  being  soluble  in  twenty-seven  parts  water,  while  the  /?-  acid 
requires  one  hundred  and  fifteen  parts. 

(5)  Anthracene-sulphonic  Acid,  CUH9.SO3H,  is  produced  similarly  to 
the  above,  or  by  the  reduction  of  sodium  anthraquinone-sulphonate  with 
zinc-dust  and  ammonia. 

Phenol-sulphonic  Acid,  C6H4(OH)SO3H. — Three  isomers  are  known, 
two,  the  ortho-  and  para-,  being  produced  by  the  direct  action  of  sulphuric 
acid  upon  phenol,  while  the  meta-  compound  must  be  produced  by  other 
means.  The  ortho-  acid  is  largely  obtained  when  one  part  of  phenol  is 
slowly  mixed  with  one  part  of  sulphuric  acid,  care  being  taken  to  keep  the 
temperature  from  rising.  The  para-  acid  will  be  obtained  if  the  mixture 
be  heated  to  100°.  These  bodies  are  much  employed  as  antiseptics  under 
various  names ;  the  para-  compound,  also,  in  the  production  of  picric 
acid. 

Naphthol-sulphonic  Acids. — The  two  naphthols  are  easily  converted  into 
mono-sulphonic  acids  upon  being  heated  to  100°  C.  with  concentrated  sul- 
phuric acid  ;  disulphonic  acids  being  produced  if  the  temperature  reaches 
110°  C.  0-naphthol-sulphonic  acid,  C10H,.SO3H.OH.  One  hundred  parts 
of  /9-naphthol  are  added  to  two  hundred  parts  of  sulphuric  acid  (specific 

26 


402  THE   ARTIFICIAL   COLORING   MATTERS. 

gravity  1.84)  and  carefully  heated  to  50°  or  60°,  when  two  acids  result, 
ordinary  @-naphthol-sulphonic  acid  (known  also  as  "  Schqffer's  acid"  or 
"acid  S")  and  fi-naphthol-a-sulphonic  acid  ("Bayer's  acid"  or  "acid  B"). 
When  converted  into  their  sodium  salts  they  can  be  separated  by  treatment 
with  alcohol,  in  which  menstruum  the  latter  acid  is  more  soluble  than  the 
former.  They  are  extensively  used  for  the  production  of  the  crocei'n  scarlets ; 
and  upon  nitration  yield  other  colors  of  importance.  If  the  mixed  acid  and 
naphthol  is  heated  to  about  20°  C.  Bayer's  acid  will  be  formed,  while  the 
employment  of  a  temperature  about  90°  will  cause  the  formation,  as  the 
chief  product,  of  Schaffer's  acid. 

Disulphonic  Acids  of  0-Naphthol,  C10H5(SO3H)2OH,  are  obtained  when 
the  naphthol  is  subjected  to  a  temperature  of  100°  to  110°  with  three  times 
its  weight  of  sulphuric  acid  (specific  gravity  1.84).  Upon  dilution  milk 
of  lime  is  added,  the  precipitated  calcium  sulphate  filtered  off,  carbonate  of 
soda  added,  and  the  whole  evaporated  to  dryness,  and  lixiviated  with  alcohol, 
when  "salt  G"  (yellow  shade)  is  dissolved  from  "salt  R"  (red  shade). 
Ordinarily,  after  the  addition  of  the  carbonate  of  soda,  the  solution  is  used 
without  further  treatment. 

Anthraquinone-sulphonic  Acid,  C6H4(CO)2C6H3.SO3H,  is  formed  when 
anthraquinone  is  treated  with  fuming  sulphuric  acid  to  160°  C.  The  unal- 
tered anthraquinone  is  separated,  the  solution  neutralized  with  soda,  when 
the  white  soda  salt  settles  out.  The  free  acid  occurs  in  yellow  plates,  solu- 
ble in  water  and  in  alcohol.  When  fused  with  either  caustic  soda  or  pot- 
ash alizarin  is  obtained  (when  the  anthraquinone  disulphonic  acid  is  used, 
either  by  itself  or  in  the  melt,  purpurin  is  produced  along  with  alizarin) ; 
anthraquinone-sulphonic  acid  being  employed  directly  for  the  production  of 
this  most  valuable  coloring  matter. 

Sulphanilic  (p-amidobenzene-sulphonic)  Acid,  C0H4(HSO3)NH2,  is  made 
by  the  action  of  sulphuric  acid  upon  aniline  at  about  190°  C.  Is  used 
very  largely  as  basis  of  the  manufacture  of  dye-colors. 

Naphthylamine-sulphomc  Acids  are  prepared  from  naphthylamine  by 
treatment  with  sulphuric  acid  and  the  application  of  heat.  Several  deriva- 
tives are  produced,  which,  however,  find  limited  application,  mainly  in  some 
patented  specialties. 

7.  PYRIDINE  AND  QUINOLINE  BASES. — Pyridine,  C5H5N,  is  regarded 
as  a  benzene  nucleus  (C6H6),  with  one  of  the  CH  groups  replaced  by  an 
atom  of  nitrogen.  It  is  obtained  when  bone  oil  or  other  nitrogen-contain- 
ing organic  bodies  are  distilled.  It  possesses  a  pungent  odor,  is  liquid,  boils 
at  116.7°,  and  is  soluble  in  water;  specific  gravity  .986.  A  large  number 
of  the  pyridine  derivatives  bear  a  relationship  to  the  alkaloids. 

Quinoline  (Chinoline),  C9H7N,  differs  from  pyridine  in  that  naphthalene 
is  the  base,  C10H8,  one  nitrogen  atom  replacing,  as  before,  one  of  the  CH 
groups.  Quinoline  is  readily  prepared  by  carefully  heating  in  a  flask  one 
hundred  and  twenty  grammes  glycerine,  thirty-eight  grammes  aniline, 
twenty-four  grammes  nitrobenzene  (oxidizing  agent),  with  one  hundred 
grammes  concentrated  sulphuric  acid  ;  when  the  reaction  is  over,  boil  for 
two  or  three  hours,  dilute  with  water,  and  remove  the  unchanged  nitroben- 
zene with  steam,  saturate  with  caustic  alkali,  distil,  add  sulphuric  acid  and 
sodium  nitrite  (NaNO2)  to  destroy  any  aniline  present,  make  alkaline,  and 
again  distil.  Quinoline  is  a  colorless  fluid,  having  a  penetrating  odor, 
highly  refractive,  becoming  brown  upon  exposure  to  the  air ;  boils  at  238°  ; 
specific  gravity  1.094  at  20°. 


RAW   MATERIALS.  403 

Quinaldine  (a-Methyl-quinoline),  C9H6(CH3)N. — Obtained  by  the  action 
of  hydrochloric  acid  upon  paraldehyde  and  aniline,  for  several  hours,  with 
the  aid  of  heat.  It  has  a  faint  odor,  is  fluid,  and  boils  at  238°  to  239°. 
Technically  employed,  mainly  for  the  production  of  "  quinoline  yellow," 
cyanine  blue,  quinoline  red,  etc. 

Acridine,  C13H9N. — Anthracene  is  the  base  from  which  this  derivative 
is  obtained  by  a  substitution  of  a  nitrogen  atom  for  one  of  the  CH  groups, 
as  in  the  previous  instances  many  derivatives  of  the  above  bodies  exist, 
which  have  considerable  interest,  but  no  technical  importance  is  attached  to 
them  as  raw  materials. 

8.  DIAZO-  COMPOUNDS. — These  form  the  most  extensive,  and  probably 
the  most  thoroughly  investigated  of  the  several  groups  of  coal-tar  colors. 
They  are  produced  where  nitrous  acid  (obtained  from  starch  and  nitric 
acid)  is  allowed  to  act  upon  the  primary  amines  of  the  aromatic  series,  in 
which  case  the  following  change  is  noted,  assuming  aniline  nitrate  to  be 
acted  upon : 

*  C6H5NH2.HNO3  +  HO.NO  =  C6H6N=N.NO3  +  2H2O. 

(Diazo-benzene  nitrate.) 

Aniline  hydrochloride,  treated  in  the  same  manner,  will  yield  diazo-benzene 
chloride : 

C6H5.NH2.HC1  +  HO.NO  =  C6H5N=N.C1  +  2H2O. 

The  diazo-  compounds  differ  from  those  of  the  azo-  group  in  that  one  of  the 
bonds  of  the  diatomic  nitrogen  group  — N  =  N —  is  satisfied  with  an  hydro- 
carbon radicle,  while  in  the  latter  it  is  saturated  with  an  atom  of  oxygen, 
nitrogen,  bromine,  chlorine,  etc.,  or  with  an  acid  or  basic  group.  The 
annexed  list  of  diazo-  bodies  illustrates  the  above : 

C6H5N  =  NCI Diazo-benzene  chloride, 

(C6H5.N  =  N)2SO4 "  «        sulphate, 

C6H5N  =  N.Br "  "        bromide. 

C6H5N  =  N.NH.C6H5 Diazo-amido-benzene. 

The  azo-  compounds  have  the  two  nitrogen  atoms  ( — N  =  N — )  united, 
each  to  a  hydrocarbon  group ;  mixed  azo-  compounds  result  if  these  hydro- 
carbon groups  are  not  identical. 

(1)  Diazo-benzene  Chloride,  C6H5.N2C1,  is  formed  when  nitrite  of  soda 
(NaNO2)  is  added  to  a  solution  of  aniline  chloride  in  the  presence  of  an 
excess  of  hydrochloric  acid,  the  solution  being  kept  cool  by  means  of  ice. 
The  product  finds  application  in  the  manufacture  of  aniline  yellow  and 
other  colors. 

Diazo-amido  Compounds  result  from  the  action  of  salts  of  the  diazo- 
derivatives  upon  the  primary  and  secondary  amines. 

Diazo-amido-benzene,  C6H5.N2.NH.C6H5,  occurs  when  nitrous  acid  is 
passed  through  a  solution  of  aniline  in  alcohol ;  or  by  adding  a  solution  of 
sodium  nitrite  to  a  mixture  of  aniline  hydrochloride  and  aniline.  Crystal- 
lizes in  golden-yellow  prisms  or  scales,  insoluble  in  water,  easily  in  ether, 
benzene,  and  alcohol ;  melting  point  91°,  exploding  at  a  higher  temperature. 

(2)  Diazo-benzene-sulphonic  Add,  C6H4.N2.SO3  (the  anhydride  of  the 
sulphonic  acid  of  diazo-benzene). — Sulphanilic  acid,  C6H4NH2.SO3H  (see 
p.  402),  is  dissolved  in  water,  and  sodium  nitrite  added,  when  the  whole 
is  poured  into  dilute  sulphuric  acid,  which  causes  a  precipitation  of  the 
crystals. 


404  THE   ARTIFICIAL    COLOEING   MATTERS. 

9.  AROMATIC  ACIDS  AND  ALDEHYDES. — The  aromatic  acids  form  a 
class  of  bodies  of  considerable  importance,  derived  from  benzenes  by  sub- 
stituting the  carboxyl  group  CO.OH  for  hydrogen.     The  simplest  of  the 
series  is  Benzoic  Acid  (Benzene-carboxylic  Acid),  C6H5.CO.OH,  which,  be- 
sides finding  extensive  application  in  medicine,  is  also  used  in  the  color 
manufacture.     It  can  be  prepared  by  a  number  of  methods,  chiefly  by  the 
sublimation  of  gum  benzoin  ;  by  treating  the  urine  of  herbivorous  animals 
with  hydrochloric  acid,  which  causes  the  hippuric  acid  to  break  up,  yield- 
ing the  acid  and  glycocine;  and  from  benzyl-chloride  after  boiling  with 
nitric  acid.     It  crystallizes  in  needles  or  scales,  lustrous,  and  odorless  when 
pure.     Specific  gravity  1.291,  melting  at  121°,  and  boiling  at  249°  ;  solu- 
ble in  alcohol,  ether,  benzene,  etc.,  sparingly  in  water. 

Phthalic  acid  (Benzene-dicarboxylic  Acid),  C6H4.(CO.OH)2. — Three  iso- 
mers  of  the  above  are  known,  but  only  the  ortho-  acid  will  be  considered. 
It  is  obtained  from  naphthalene  tetrachloride  by  heating  with  nitric  acid. 
It  can  also  be  obtained  by  heating  naphthalene  direct  in  the  presence  of 
nitric  acid,  but  this  process  is  not  much  employed.  It  occurs  in  rhombic 
crystals,  specific  gravity  1.585,  and  melting  at  213°  ;  upon  being  heated,  it 
is  liable  to  split  up  into  water  and  the  anhydride ;  soluble  in  hot  water, 
alcohol,  and  ether.  When  a  phenol  is  heated  with  the  phthalic  anhydride 
phthalems  result;  of  these,  the  resorcin  and  pyrogattol-phthaleins  are  the 
most  important,  being  the  basis  of  the  eosins  and  galleins  and  crerulems. 

Gallic  Acid  (Trihydroxybenzoic  Acid),  C6H2(OH)3.CO.OH.— This  acid 
occurs  in  several  vegetable  substances, — chiefly  gallnuts,  sumach,  tea,  etc. 
It  is  ordinarily  prepared  by  heating  gallo-tannic  acid  with  dilute  mineral 
acid,  or  by  allowing  crushed  galls  to  remain  exposed  in  a  moistened  state 
to  the  action  of  the  atmosphere  for  some  time,  when  a  fermentation  takes 
place,  after  which  boiling  with  water  removes  the  gallic  acid.  It  yields 
needle-shaped  crystals,  sometimes  white,  but  mostly  light  brown  in  color. 
Specific  gravity  1.70.  When  heated  to  220°  it  decomposes,  forming  pyro- 
gallol  (Trihydroxybenzene,  C6H3(OH)3)  and  CO2.  Gallic  acid  is  the  chief 
source  of  pyrogallol,  reference  to  the  application  of  which  has  been  made 
under  phthalic  acid. 

Benzaldehyde  (Benzoic  Aldehyde],  C6H5.CO.H. — This  body,  also  known 
as  "  Bitter  Almond  Oil,"  is  a  colorless  liquid,  possessing  an  agreeable  odor, 
and  high  refracting  power.  Specific  gravity  1.063,  boiling  at  180°,  diffi- 
cultly soluble  in  water  (1:300),  easily  in  alcohol  and  ether.  Several 
methods  are  employed  for  the  production  of  this  substance  ;  for  industrial 
purposes,  benzyl-chloride  is  boiled  with  nitrate  of  copper  and  water,  half 
of  the  contents  are  distilled,  when  the  oily  layer  is  separated  from  the  dis- 
tillate and  purified.  Mercuric  oxide  has  been  used  instead  of  the  copper  salt. 
It  finds  extensive  application  in  the  color  industry,  also  for  the  production 
of  cinnamic  and  benzoic  acid,  and  several  derivatives  of  value. 

10.  KETONES  AND  DERIVATIVES,  ANTHRAQUINONE. — The  ketones  are 
closely  related  to  the  aldehydes,  as  will  be  seen  from  their  structure, — 

CH3  —  CO  —  H,  Aldehyde,  CH3  —  CO  —  CH3,  Dimethyl-ketone  (acetone). 

The  CO  group — carbonyl — is  possessed  by  both  classes,  but  in  the  alde- 
hydes is  united,  on  the  one  hand  to  an  alcohol  radical,  and  on  the  other  to 
an  atom  of  hydrogen.  The  ketones,  however,  are  distinguished  by  having 
two  alcohol  radicals  (alkyls)  linked  by  the  CO  group. 

Benzophenone,  C6H5.CO.C6H5,  is  a  ketone  of  the  benzene  series,  and  can 
be  obtained  by  distilling  calcium  benzoate,  or  by  heating  benzoyl  chloride 


PKOCESSES   OF  MANUFACTURE.  405 

with  aluminum  chloride  and  benzene.  It  occurs  in  crystals  having  an 
aromatic  odor,  and  which  melt  at  48°  to  49°,  subliming  at  300°.  Insolu- 
ble in  water,  soluble  in  alcohol  and  ether.  It  is  of  some  importance,  to- 
gether with  the  amido-  and  oxy-  derivatives,  in  the  manufacture  of  certain 
colors. 

Acetophenone  (Phenyl-meihyl-ltetone),  C6H5.CO.CH3.  —  -This  js  a  mixed 
ketone,  and  contains  two  residues  of  Different  hydrocarbons  united  to  the 
carbonyl  group.  Acetophenone  can  be  obtained  by  distilling  a  mixture  of 
the  benzoate  and  acetate  of  calcium.  It  occurs  in  crystalline  plates,  melting 
at  14°  to  15°,  and  boils  at  198°. 

CO 

Anthraquinone,  C6H4<pQ>C6H4.  —  This  substance  is  of  the  utmost  im- 

portance in  the  manufacture  of  alizarine.  It  can  be  obtained  by  several  pro- 
cesses, the  simplest  of  which  is  probably  the  distillation  of  calcium  phthalate, 
or  by  oxidizing  anthracene  (C10H8)  with  bichromate  of  potash  and  sulphuric 
acid.  Anthraquinone  is  very  stable,  oxidizing  agents  having  but  little  effect 
upon  it.  When  heated  it  sublimes,  yielding  yellowish  rhombic  crystals. 
Specific  gravity  1.425,  melting  point  273°  ;  insoluble  in  water,  but  some- 
what in  alcohol  and  ether.  Upon  fusion  with  caustic  alkalies  it  yields  benzoic 
acid.  For  use  in  the  alizarine  process,  it  must  first  be  converted  into  the 
sulphonic  acid,  and  this  fused  with  caustic  alkali,  dissolved  in  water,  and 
the  coloring  matter  precipitated  by  a  mineral  acid,  and  sublimed.  (See 
Processes  of  Manufacture,  p.  409.) 


n.  Processes  of  Manufacture. 

1.  OF  NITROBENZENE  AND  ANILINE.  —  The  commercial  production  of 
nitrobenzene  is  carried  out  essentially  in  the  following  manner,  although  the 
details  may  vary  in  the  different  works.  Sulphuric  acid,  66°  B6.,  and  nitric 
acid,  42°  B6.  (=  seventy  per  cent.  HNO3),  are  mixed  together,  in  the  pro- 
portion of  fifteen  parts  by  weight  of  the  former  to  ten  parts  of  the  latter, 
in  a  lead-lined  wooden  tank  (preferably  situated  above  the  nitrating  appa- 
ratus) and  allowed  to  become  cold.  Three  hundred  pounds  of  this  "  nitrat- 
ing acid"  are  run  into  the  nitrating  apparatus,  either  by  gravity  or  by 
pressure,  when  the  benzene  is  allowed  to  flow  in  in  a  slow,  steady  stream. 
l)uring  the  admission  of  the  benzene  the  temperature,  which  should  be 
maintained  between  80°  C.  and  90°  C.,  is  regulated  by  means  of  water 
kept  at  about  50°  C.  circulating  around  the  vessel,  or  stopping  the  inflow, 
should  the  temperature  give  indication  of  rising,  thereby  producing  the  di- 
nitro-  derivative.  About  one  hundred  pounds  of  benzene  are  used,  although 
this  quantity  is  subject  to  change,  according  to  quality.  After  the  nitration 
is  finished,  the  contents  of  the  vessel  are  emptied  slowly  into  large  tanks, 
the  acid  layer  being  drawn  off  first,  and  the  nitric  acid  recovered  therefrom, 
and  the  nitrobenzene,  insoluble  in  the  acid,  coming  last,  is  immediately 
poured  into  a  tank  containing  water,  and  washed,  followed  by  a  wash  with 
caustic  alkali,  and  finally  agitated  with  water. 

The  quantities  by  weight  of  the  two  acids  to  effectually  nitrate  either 
benzene,  toluene,  or  xylene,  is  shown  below  : 

100  kilos,  benzene  .....  120  kilos,  nitric  acid.     180  kilos,  sulphuric  acid. 
100     "      toluene  .....  105     «          "        "        176    "  "  " 

100     "      xylene   .....    90     "          "        "        160     «  "  « 


406 


THE   ARTIFICIAL   COLORING   MATTERS. 


FIG.  113. 


Or,  of  a  standard  mixture  of  one   hundred  kilos,  nitric   acid   and  one 
hundred  and  fifty  kilos,  sulphuric  acid,  there  will  be  required  for  the 

effectual  nitration  of  one  hun- 
dred kilos,  of  the  above  tabu- 
lated hydrocarbons  three  hun- 
dred, two  hundred  and  sixty, 
and  two  hundred  and  twenty- 
five  kilos,  respectively.  The 
form  of  nitrating  apparatus 
in  use  is  usually  cylindrical, 
with  a  flat  or  round  bottom. 
Fig.  113  illustrates  the  latter 
form.  The  cover  is  provided 
with  several  openings :  /  is 
for  general  charging ;  e  is 
for  the  gas  exit,  while  pro- 
vision is  made  for  the  intro- 
duction of  the  thermometer, 
and  for  carrying  the  agitator 
shaft.  The  opening  for  with- 
drawing the  charge  is  at  g. 
The  best  plan  in  arranging 
the  plant  is  to  provide  for 
the  acid  mixing  and  nitrating 
on  one  floor,  on  the  floor  be- 
low the  washing,  and,  if  de- 
sirable, a  steam  still  employed 
to  separate  the  benzene  which 
has  not  been  acted  on  by  the 
acids,  and  which  is  always 
found  dissolved  in  the  nitro- 
benzene. On  the  lowest  floor, 
the  alkali  and  final  water- 
wash.  If  all  the  operations 
are  performed  on  one  level,  a 
"monte-jus"  should  be  used 
for  the  transportation  of 
liquids. 

Aniline  ("  Aniline  Oil"  of  commerce). — Aniline  is  obtained  by  the  treat- 
ment of  nitrobenzene  with  iron  filings  or  scrapings  and  hydrochloric  acid. 
The  apparatus  employed  are  generally  of  two  kinds,  vertical  and  horizontal, 
the  method  of  working  being  in  each  case  the  same.  In  the  former,  the 
agitator  is  attached  to  an  upright  hollow  shaft,  so  constructed  as  to  provide 
for  the  admission  of  steam  to  the  bottom  of  the  vessel.  The  cover  supports 
the  gearing,  and  gooseneck  for  leading  the  vapors  to  the  condenser,  etc. 
The  horizontal  form  is  shown  in  Fig.  114 ;  the  construction  provides  for 
agitators  attached  to  a  horizontal  revolving  shaft  passing  through  boxes  in 
the  heads.  Steam  enters  through  the  pipes  underneath.  A  steady  supply 
of  fine  iron  is  maintained  by  means  of  the  mechanical  feed  on  the  cover. 
The  operation  is  conducted  by  adding  some  of  the  iron  filings  with  water, 
followed  by  the  acid  and  nitrobenzene ;  steam  is  turned  on,  and,  the  agita- 
tors set  in  motion,  at  once  the  reaction  begins,  and  a  mixture  of  nitroben- 


PROCESSES   OF   MANUFACTUEE. 


407 


FIG.  114. 


zene,  aniline,  and  water  appears  in  the  condenser,  which  is  continually 
returned  to  the  main  body  in  the  apparatus ;  after  the  reaction  has  com- 
menced and  the  distillate  comes  over  regularly,  the  iron  can  be  fed  steadily, 
or  at  uniform  intervals.  If  all  the  iron  is  added  at  once,  serious  loss  is 
occasioned  by  a  reduction  of  aniline  to 
benzene  and  ammonia.  For  a  charge 
of  six  hundred  kilos,  of  nitrobenzene, 
about  seven  hundred  kilos,  of  iron  filings 
will  be  required  and  sixty  kilos,  of  21° 
Be\  hydrochloric  acid.  The  solubility 
of  the  distillate  in  hydrochloric  acid  is 
noted,  until  a  point  is  reached  at  which  no 
nitrobenzene  separates  in  an  unaltered 
condition.  Formerly  it  was  the  general 
practice  to  add  lime  to  the  tank,  and 
distil  off  the  aniline  by  means  of  steam  ; 
now  the  contents  are  emptied  into  large 
tanks  containing  water  and  allowed  to 
subside  for  a  day  or  more,  when  the 
lower  layer,  consisting  of  aniline,  is 
drawn  off  and  pumped  into  a  large  iron 
still  mounted  over  an  open  fire  and  recti- 
fied. One  hundred  parts  of  nitrobenzene 
will  yield  about  seventy -five  parts  of 

aniline  if  the  process  is  carefully  attended.     Ordinarily,  the  yield  will  be 
from  seventy-one  to  seventy-four  parts. 

2.  OF  PHENOLS,  NAPHTHOLS,  ETC. — Phenol.  —  See  Chapter  XL, 
"  Coal-tar  Distillation,"  p.  377. 

Resorcin  is  manufactured  commercially  from  the  soda  salt  of  benzene- 
disulphonic  acid,  by  fusing  with  caustic  soda  and  subsequent  extraction  with 
ether.  One  hundred  kilos,  of  fuming  sulphuric  acid  are  contained  in  a  large 
cast-iron  vessel  provided  with  means  for  agitating  the  contents,  and  into  it 
is  gradually  allowed  to  flow  twenty-eight  kilos,  of  benzene ;  the  whole  is 
maintained  at  a  moderate  temperature  for  several  hours,  and  finally  raised 
to  about  270°  C.  to  275°  C.,  after  which  the  contents  are  transferred  to  a 
large  volume  of  water  and  boiled.  Lime  is  added,  the  precipitated  sul- 
phate removed,  and  the  soluble  lime  salt  decomposed  by  the  addition  of  the 
requisite  quantity  of  carbonate  of  soda ;  carbonate  of  lime  is  precipitated, 
filtered,  and  the  precipitate  freed  from  the  excess  of  solution  in  the  filter- 
press.  This  solution  is  evaporated  to  dryness  in  iron  pans.  For  the  re- 
sorcin  melt,  sixty  kilos,  of  the  above  salt  and  one  hundred  and  fifty  kilos, 
of  76°  caustic  soda  are  fused  together  for  about  eight  hours  at  a  temperature 
near  270°  ;  when  fusion  is  finished  the  melt  is  cooled,  leached  out  with  boil- 
ing water,  and  boiled  with  hydrochloric  acid  for  some  time,  when  the  heat 
is  withdrawn,  and  the  solution  allowed  to  become  cold,  and  subjected  to  the 
action  of  ether  or  benzene  in  an  extraction  apparatus,  which  removes  the  re- 
sorcin.  The  benzene  is  distilled  off  and  recovered,  while  the  crude  resorcin 
remaining  is  dried  at  about  210°.  Pure  resorcin  is  obtained  from  the 
above  by  distillation. 

Pyrogallol. — Several  processes  are  employed  for  the  production  of  this 
substance,  all  being  based  upon  the  use  of  an  aqueous  extract  of  gallnuts 
or  of  gallic  acid.  One  process  is  carried  out  by  heating  a  glycerine  solu- 


408  THE   AETIFICIAL   COLORING   MATTERS. 

tion  of  gallic  acid  to  about  200°  C.,  diluting  with  an  equal  volume  of  water, 
and  extracting  therefrom  the  pyrogallol  with  ether,  which  is  evaporated  off 
and  recovered.  Another  process  is  to  heat  one  part  of  gallic  acid  and  two 
parts  water  in  a  closed  vessel  to  200°  to  210°  C.  for  half  an  hour,  cooled, 
and  heated  with  bone-black,  the  solution  filtered,  and  evaporated  to  the 
crystallizing-point.  The  crystals  are  further  purified  by  being  distilled  in  a 
vacuum. 

Alpha-  and  Beta-Naphihols. — a-Naphthol  is  manufactured  on  a  large  scale 
in  the  same  general  manner  as  resorcin.  a-Naphthalene-sulphonic  acid  is 
first  prepared  by  heating  naphthalene  with  fuming  sulphuric  acid  to  90°  C., 
diluting  with  water,  and  completely  neutralizing  with  milk  of  lime,  filtering 
from  the  magma  of  sulphate  which  is  passed  through  a  filter-press,  the  solution 
of  the  soluble  lime  salt  decomposed  with  carbonate  of  soda,  filtered  and  pressed 
again,  and  the  solutions  finally  evaporated  to  crystallization,  when,  on  cool- 
ing, the  /3-naphthalene-sulphonate  separates  out  and  is  removed.  The  «-  salt 
is  fused  with  caustic  soda,  when  the  corresponding  naphthol  is  obtained. 

fi-Naphthol,  of  much  more  commercial  importance  than  the  preceding,  is 
manufactured  similarly.  The  naphthalene-sulphonic  acid  is  made  as  above, 
but  at  a  temperature  of  200°  C.,  in  order  to  obtain  a  large  yield  of  the  /?-  de- 
rivative. This  is  converted  into  the  soda  salt,  dried,  and  one  part  by  weight 
fused  with  two  parts  of  caustic  soda  dissolved  in  the  smallest  quantity  of 
water,  at  a  temperature  of  270°  to  300°  C. ;  when  the  reaction  is  over,  the 
melt  is  treated  with  water,  the  /?-naphthol  separated  by  the  addition  of  hy 
drochloric  acid,  filtered,  dried,  melted,  and  poured  into  cylindrical  moulds. 

3.  OF  AROMATIC  ACIDS  AND  PHTHALEINS. — Benzole  Add  can  be  man- 
ufactured by  several  processes  and  from  different  sources.  For  technical 
purposes  the  manufacture  from  benzoin  resin  and  from  hippuric  acid  need 
not  be  considered,  as  it  is  made  almost  exclusively  on  a  large  scale  from  the 
chlorine  derivatives  of  toluene,  such  as  benzal  chloride,  C6H5.CHC12,  and 
benzo-trichloride,  C6H5CC13.  The  former,  when  heated  with  water  or  milk 
of  lime  under  pressure,  is  changed  into  benzaldehyde,  C6H5CHO,  which, 
however,  always  has  some  benzoic  acid  formed  with  it  as  a  side-product. 
The  benzo-trichloride,  similarly  with  water  or  milk  of  lime,  yields  benzoic 
acid  according  to  the  reaction  C6H5.CC13  +  2K£>  =  C6H5.COOH  -f  3HC1. 
The  benzoic  acid  so  obtained  is  almost  always  contaminated  by  some  chlor- 
benzoic  acid. 

Phthalie  Acid  and  Phthalic  Anhydride. — The  process  for  their  manu- 
facture is  as  follows.  Naphthalene  is  converted  into  the  tetrachloride  de- 
rivative by  means  of  chlorine  gas  acting  upon  it  in  the  fused  state,  or  by 
grinding  naphthalene  with  an  alkaline  chlorate  and  sufficient  moisture  to 
cause  the  mass  to  cohere,  when  it  is  dried  in  small  lumps,  which  are  im- 
mersed in  concentrated  hydrochloric  acid,  when  the  tetrachloride  separates 
as  a  sticky  mass,  afterwards  becoming  hard.  This  is  taken  and  acted  upon 
by  concentrated  nitric  acid,  heated  till  the  solution  is  complete  and  the  excess 
of  nitric  acid  has  been  distilled  off,  when,  upon  cooling,  the  phthalic  acid 
separates  out  in  crystals.  The  anhydride  is  obtained  by  acting  upon  phthalic 
acid,  heated  to  about  200°  C.,  with  carbon  dioxide  and  subliming. 

Phthale'ins. — When  phthalic  acid  or  its  anhydride  acts  upon  phenols  a 
class  of  bodies  termed  "  phthaleins"  are  formed  with  elimination  of  water. 
Phenolphthale'in  is  manufactured  by  heating  the  anhydride,  phenol,  and  sul- 
phuric acid  for  ten  to  twelve  hours  at  120°  C. ;  the  sulphuric  acid  acts  only 
as  a  dehydrating  agent.  The  melt  is  boiled  with  water,  the  residue  dis- 


PROCESSES   OP   MANUFACTURE. 


409 


solved  in  caustic  soda,  and  the  phthalem  is  precipitated  upon  the  addi- 
tion of  an  acid.  Resorcin-phthalein,  or  Fluoreseein,  is  obtained  by  heating 
three  parts  of  phthalic  anhydride  with  about  four  parts  of  resorcin  until 
the  fusion  yields  no  more  vapors,  and  becomes  solid  at  a  temperature  not 
exceeding  210°  C.  The  melt  is  dissolved  in  dilute  caustic  soda,  with  an 
addition  of  phosphate  of  soda  and  chloride  of  calcium  to  remote  impurities. 
The  fluorescei'n  is  precipitated  from  the  solution  by  the  addition  of  dilute 
hydrochloric  acid. 

4.  OF  ANTHRAQUINOXES,  ETC. — Anthracene  in  a  finely-divided  state 
is  suspended  in  water  by  agitation,  and  oxidized  by  means  of  potassium 
bichromate  and  sulphuric  acid  at  a  boiling  temperature ;  allowed  to  cool, 
and  the  anthraquinone  is  collected  on  filter- frames,  washed  with  water  and 
dried,  and  for  further  purification  is  treated  with  concentrated  sulphuric 
acid,  and  heated  to  110°  to  120°  C.,  when  the  dark  mass  obtained  is  treated 
with  steam,  which  causes  a  dilution,  followed  by  a  gradual  separation  of 
the  anthraquinone  in  crystals.  These  are  washed  with  hot  water,  and  after- 
wards with  hot  dilute  soda  to  remove  organic  acids.  The  yield  is  about 
fifty  to  fifty-five  per  cent,  of  the  weight  of  the  anthracene  used. 

Anthraquinone-monosulphonic  Acid.  (See  p.  402.) — This  is  manufac- 
tured by  heating  one  hundred  kilos,  anthraquinone  with  one  hundred  kilos. 

FIG.  115. 


fuming  'sulphuric  acid  (containing  forty-five  to  fifty  per  cent,  anhydride)  to 
160°  C.  in  an  enamelled  cast-iron  vessel  mounted  in  an  oil-bath.  By  vary- 
ing either  the  quantity  of  sulphuric  acid  or  the  temperature  the  alpha-  or 
beta-disulphonic  acid  will  result.  The  separation  of  the  two  latter  from 
the  mono-sul phonic  acid  is  effected  by  converting  the  sulphonic  acids  into 
lead  salts,  decomposing  these  with  carbonate  of  soda,  and  acting  upon  the 


410  THE   ARTIFICIAL   COLORING  MATTERS. 

resulting  soda  salts  with  dilute  sulphuric  acid,  which  has  but  a  slight  solvent 
action  upon  the  mono-sulphonic  acid. 

Alizarin.  —  The  alizarin  process  is  carried  on  in  large  iron  vessels  or 
autoclaves,  mounted  as  shown  in  Fig.  115.  To  the  central  shaft  D  agita- 
tors are  attached,  so  that  the  charge  may  be  constantly  mixed.  F  is  a 
thermometer,  and  the  openings  in  the  top  to  the  right  are  for  introducing 
the  charge,  and  the  small  one  on  the  left  for  admitting  steam  and  water. 
The  process  is  commenced  by  melting  two  hundred  and  fifty  to  three  hun- 
dred parts  of  caustic  soda  in  a  small  quantity  of  water,  and  then  adding 
twelve  to  fifteen  parts  of  chlorate  of  potash  and  one  hundred  parts  of  the 
sodium  anthraquinone-sulphonate,  when  the  vessel  is  closed  and  the  agitator 
put  in  motion,  the  whole  being  kept  at  a  temperature  of  180°  C.  for  two  days, 
when  it  is  allowed  to  cool,  dissolved  in  a  large  quantity  of  water,  and  the 
alizarin  precipitated  by  the  addition  of  hydrochloric  acid.  The  alizarin 
is  washed  to  free  it  from  soda  salts,  passed  through  filter-presses,  and  is 
ready  to  be  either  dried  and  ground,  or  ground  in  glycerine  to  a  paste. 
Neutralizing  the  soda  solution  with  sulphurous  acid  instead  of  with  hydro- 
chloric acid  enables  a  recovery  of  the  caustic  soda.  The  yield  from  one 
hundred  kilos,  anthraquinone  is  one  hundred  and  five  to  one  hundred  and 
ten  kilos,  alizarine  (Schultz).  Several  processes  are  employed,  varying 
mainly  in  the  duration  of  the  melt  and  in  the  proportion  of  materials  used. 
Instead  of  soda,  lime  is  employed,  in  which  case  a  "  lake"  is  formed. 

5.  OF  QUINOLINE  (CRINOLINE)  AND  ACRIDINE.  —  Quinoline  is  pro- 
duced from  nitrobenzene  and  aniline.     Twenty-four  grammes  of  the  for- 
mer and  thirty-eight  grammes  of  the  latter,  with  one  hundred  and  twenty 
grammes  of  glycerine,  are  placed  in  a  flask  (provided  with  a  return  con- 
denser) containing  one  hundred  grammes  of  concentrated  sulphuric  acid  ; 
when  the  reaction  is  over,  the  contents  are  boiled  for  some  time,  diluted,  and 
the  tinconsumed  nitrobenzene  is  distilled  off;  an  excess  of  alkali  is  added 
to  the  solution,  and  the  quinoline  distilled  off  with  a  current  of  steam.     It 
can  also  be  obtained  from  crude  quinoline  from  coal-tar  with  phthalic  an- 
hydride and  zinc  chloride.     Acriaine  is  found  along  with  crude  anthracene, 
from  which  it  is  separated  by  treatment  with  dilute  sulphuric  acid,  precipi- 
tating with  chromate  of  potash,  recrystallizing,  precipitating  by  ammonia, 
dissolving  in  hot  water,  from  which  it  separates  in  crystals  on  cooling. 

6.  SULPHONATING.  —  This  general  process  consists  in  dissolving   the 
compound  to  be  changed  in  fuming  sulphuric  acid,  whereby  one  or  more 
H  atoms  are  replaced  by  HSO3  groups,  producing  mono-,  di7,  or  trisul- 
phonic  acids.     Examples  of  this  process  are  given  under  Resorcin  (see  p. 
407),  the  Naphthols  (see  p.  408),  and  will  frequently  .be  referred  to  in 
classifying  the  artificial  dye-colors. 

7.  DIAZOTIZING.  —  By  the  action  of  nitrous  acid  upon  primary  aromatic 
amines  a  diazo-  compound  is  formed,  as  in  the  following  reaction  : 


C6H5.N  ;  H2H  !  N03=C6H5.N=KN03-f  2H2O. 

+  NI  O2Hj 

These  diazo-  compounds  are  susceptible  of  a  great  variety  of  reactions 
whereby  other  groups  or  atoms  of  elements  may  be  substituted.  Thus,  by 
the  aid  of  the  diazotizing  reaction  it  is  possible  to  replace  a  NO2  or  a  NH2 
group  by  OH,  H,  Cl,  Br,  I,  ON,  etc.  It  is  therefore  of  the  greatest  im- 
portance in  synthetic  organic  chemistry. 


PEODUCTS.  411 

The  process  is  carried  out  in  one  of  two  general  ways :  (or)  by  conduct- 
ing a  current  of  nitrous  acid  gas  through  a  solution  of  the  substance  to  be 
diazotized,  the  nitrous  acid  in  this  case  being  most  conveniently  obtained  by 
acting  upon  starch  with  concentrated  nitric  acid  in  a  suitable  generator,  or 
(b)  by  diazotizing  in  a  bath  together  with  the  nitrous  acid-yielding  substance 
(nitrite  of  soda  generally).  In  this  case  the  gas  is  evolved  by  adding  an 
acid,  usually  sulphuric,  to  the  solution.  Diazotizing  is  always  conducted  at 
a  low  temperature. 

m.   Products. 

It  would  be  impossible  in  the  space  of  this  chapter  to  do  more  than  give 
a  classification  of  the  artificial  dye-colors  and  enumerate  a  few  of  the  more 
important  under  each  group.  The  number  of  distinct  products  has  already 
run  far  into  the  thousands,  and  the  trade-names  by  which  many  are  exclu- 
sively known  frequently  bear  so  little  relation  to  the  chemical  names  that  it 
would  be  idle  for  us  to  attempt  to  cover  the  ground  in  any  other  way  than 
by  a  simple  outlining  at  present.  But  before  taking  up  this  classification  it 
will  be  well  to  examine  what  general  principles,  if  any,  underlie  the  pro- 
duction of  a  dye-color.  O.  N.  Witt  *  has  proposed  a  theory  which  explains 
in  a  very  simple  way  this  color  formation  in  the  aromatic  series.  He  names 
a  series  of  radicals  or  groups  which  by  their  entrance  alone  or  with  others 
change  a  colorless  hydrocarbon  into  a  colored  compound.  These  radicals, 
which  he  calls  "  chromophor"  groups,  are  only  capable  of  producing  the 
"  chromogens,"  or  parent  substances  of  dye-colors,  which  chromogens,  how- 
ever, are  at  once  changed  into  dye-colors  of  distinct  basic  or  acid  character 
when  a  salt- forming  group  enters.  Thus,  from  two  molecules  of  benzene 
by  the  entrance  of  the  chromphor  group  — N  =  N —  is  formed  azo-benzene, 
an  orange-colored  chromogen,  but  not  capable  of  dyeing  silk  or  wool. 
When  the  NH2  group  enters  there  results,  however,  amido-azo-benzene,  a  real 
dyestuff.  Or  from  benzene  by  the  entrance  of  the  chromophor  group  NO2 
is  formed  the  chromogen  trinitro-benzene,  which  by  the  entrance  of  the  salt- 
forming  group  OH  becomes  trinitro-phenol  (or  picric  acid),  a  yellow  dye- 
color. 

Witt  indicates  some  eleven  of  these  chromophor  groups,  to  which  we 
shall  refer  under  the  appropriate  heads  in  our  classification.  Of  salt-form- 
ing groups  which  change  the  chromogens  to  dyestuffs,  two  are  specially  to 
be  noted,  the  amido  group  NH2,  which  imparts  a  basic  character  to  the  dye- 
color,  and  the  hydroxyl  group  OH,  which  gives  the  dye-color  an  acid  char- 
acter. Almost  all  dye-colors  are  changed  to  colorless  compounds  by  the 
action  of  reducing  agents.  The  nitro-  compounds  are  changed  into  the 
corresponding  amido-  derivatives,  the  azo-  compounds  into  hydrazo-  or  even 
amido-  compounds,  while  more  complex  dye-colors  are  changed  by  careful 
reduction  into  bodies  richer  in  hydrogen,  which  are  known  as  "  leuco" 
compounds.  From  these  "  leuco"  compounds  the  corresponding  dye-colors 
are  then  formed  more  or  less  easily  by  oxidation.  In  some  cases  atmos- 
pheric oxidation  alone  suffices,  as  with  indigo,  in  others  more  energetic 
oxidizing  agents,  such  as  lead  peroxide,  are  needed. 

Again,  the  study  of  dye-colors  soon  shows  that  they  possess  different 
characters  with  reference  to  the  ease  with  which  they  may  be  fastened  upon 


Berichte  der  Chem.  Ges.,  ix.  p.  522. 


412  THE   ARTIFICIAL   COLORING  MATTERS. 

the  fibre  to  be  dyed  or  the  kind  of  mordant  needed  to  effect  such  fastening 
upon  the  fibre.  We  therefore  distinguish  between  basic,  acid,  and  indiffer- 
ent or  neutral  dyestuffs.  Basic  dyes  like  magenta  fasten  upon  the  animal 
fibre  at  once,  and  upon  the  vegetable  fibres  after  treatment  with  tannic  acid 
and  similar  acid  mordants.  They  are  used  in  the  form  of  their  salts.  The 
acid  dyes  are  frequently  sparingly  soluble,  and  are  either  brought  into 
soluble  condition  by  forming  alkaline  salts  and  sulphonic  derivatives,  which 
are  then  used  for  dyeing,  or  they  are  used  with  fibres  previously  mordanted 
with  metallic  hydrates  or  salts,  as  in  the  case  of  alizarin.  In  the  latter 
case,  however,  the  color  acid  forms  a  variety  of  different  colored  compounds 
(lakes)  with  the  different  bases.  To  the  third  class  (indifferent  or  neutral 
bodies)  belongs  indigo-blue  and  some  other  substances. 

The  classification  which  is  now  generally  accepted  is  that  based  in  the 
main  upon  Witt's  chromophor  groups,  and  we  will  simply  note  a  few  illus- 
trative compounds  under  each  group. 

1.  ANILINE  OR  AMINE  DYE-COLORS. 

x  Q—       \ 

(a)  TRIPHENYL-METHANE  DYES  ^Chromophor  group,       |_ ^  V — 

Benzaldehyde  Green  (or  Malachite  Green),  known  also  under  a  variety  of 
other  names,  is  made  by  the  action  of  benzaldehyde  upon  dimethyl-aniline. 
The  commercial  dye  is  the  oxalate  or  zinc  chloride  double  salt. 

Brilliant  Green  (or  Solid  Green)  is  the  corresponding  derivative  from 
diethyl-aniliue.  The  sulphate  or  zinc  chloride  salt  is  used  as  dye. 

Magenta  (Aniline  Red,  or  Fuchsine)  is  a  mixture  of  the  chlorhydrates 
of  para  rosaniline  and  rosaniline,  and  is  obtained  by  oxidizing  aniline  oil  with 
arsenic  acid  or  nitrobenzene.  A  large  number  of  side-products  are  obtained 
in  the  manufacture  of  magenta,  and  have  been  used  under  the  names  of  cerise, 
cardinal,  amaranth,  chrysaniline,  phosphine,  maroon,  mauvaniline,  etc. 

Add  Magenta  (Fuchsine  S)  is  the  sodium  or  ammonium  salt  of  para- 
rosaniline  and  rosaniline  trisulphonic  acids,  and  is  prepared  by  sulphonating 
the  ordinary  magenta. 

Aniline  Blue  (spirit  soluble  Blue)  is  a  salt  of  triphenylated  para-rosani- 
line,  and  is  made  by  the  action  of  a  large  excess  of  aniline  upon  rosaniline. 
If  magenta  is  used  instead  of  rosaniline  a  reddish-blue  is  obtained. 

Diphenylamine  Blue  (spirit  soluble)  is  probably  the  chlorhydrate  of  tri- 
phenylated para-rosaniline,  and  is  made,  as  the  name  indicates,  from  di- 
phenylamine,  which  is  heated  with  oxalic  acid  to  120°  to  130°  C. 

Alkali  Blue  (Nicholson's  Blue,  Soluble  Blue)  is  the  sodium  salt  of  themono- 
sulphonic  acid  of  a  spirit  soluble  blue,  and  is  made  by  sulphonating  the  latter. 

Hochst  New  Blue  is  the  calcium  salt  of  the  di-  or  tri-sulphonic  acid  of 
trimethyl-triphenyl-pararosaniline. 

Hofmann's  Violets  consist  of  salts  of  the  ethyl  and  methyl  derivatives 
of  rosaniline  and  pararosaniline,  and  are  made  by  the  action  of  methyl  or 
ethyl  chloride  or  iodide  upon  magenta  in  the  presence  of  caustic  soda.  It 
is  of  historic  interest,  but  has  been  replaced  almost  completely  by  methyl 
violet. 

Methyl  Violet  is  a  salt  of  pentamethyl  pararosaniline,  and  is  produced 
by  the  direct  oxidation  of  the  purest  dimethylaniline  with  copper  chloride. 

Add  Violet  is  obtained  by  condensing  dimethyl-p-amido-benzaldehyde 
with  ethyl-benzylaniline-sulphonic  acid,  and  oxidation  of  the  product. 

Methyl  Green. — This  dye  is  formed  by  the  action  of  methyl  chloride 
upon  methyl  violet.  The  commercial  dye  is  the  zinc  double  chloride. 


PRODUCTS.  413 

(6)  DIPHENYL-M  ETHANE  DYES. — Auramine,  an  important  yellow  dye, 
is  prepared  by  the  action  of  phosgene  gas,  COC12,  upon  dimethylaniline  and 
heating  the  product  with  sal  ammoniac  and  zinc  chloride  to  from  150°  to 
160°  C. 

Pyronine  is  a  red  dye  obtained  by  condensing  formaldehyde  with  di- 
methyl-m-amidophenol  and  oxidizing  the  product. 

(c)  AZINES     (EUEHODINES     AND     SAFRANINES). Chromophor     group 

=N — N=.  Neutral  Red  (Toluylen  Red)  is  a  basic  dye-color  prepared 
by  the  action  of  nitroso-dimethyl-aniline  upon  w-toluylen-diamine.  It  is 
used  with  cotton  after  mordanting  with  tannic  acid  and  tartar  emetic. 

Safranine  (Aniline  Rose)  is  prepared  by  the  oxidation  of  amidoazoto- 
luene  and  toluidine,  or  of  p-toluylen-diamine,  ortho-toluidine,  and  aniline. 
The  commercial  salt  is  the  chlorhydrate  of  the  safranine  base. 

Naphthalene  Red  (Magdala  Red)  is  the  compound  in  the  naphthalene 
series  corresponding  to  the  preceding.  It  is  obtained  by  fusing  the  chlor- 
hydrate of  a-naphthylen-diamine,  a-naphthylamine,  and  amidoazonaphtha- 
lene.  It  forms  a  dark-brown  powder,  soluble  in  alcohol  with  strong  red 
fluorescence.  It  is  used  largely  in  silk-dyeing  and  for  velvet  because  of  its 
fine  color  and  fluorescence. 

Mauvein  (Perkin's  Violet)  is  of  historic  interest  mainly  as  the  first  ani- 
line color.  It  was  obtained  by  W.  H.  Perkin  in  1856  by  the  oxidation  with 
sulphuric  acid  and  bichromate  of  potash  of  a  mixture  of  aniline  and  tolui- 
dine. 

Methylene  Violet  is  a  reddish- violet  dye  obtained  by  the  action  of  hydro- 
chloride  of  nitrosodimethylaniline  upon  a  mixture  of  the  hydrochlorides  of 
m-  and  j?-xylidine. 

Indoines  are  basic  coloring  matters  dyeing  cotton  deep  shades  from  dark 
violet  to  indigo-blue,  fairly  fast  to  light  and  washing.  They  are  made  by 
combining  diazotized  safranines  with  a-  and  /9-naphthol  and  conversion  into 
hy  droch  lorides. 

(d)  INDULINES  AND   NIGROSINE. — Induline,  spirit  soluble  (Coupler's 
Blue,  Guernsey  Blue,  etc.)  is  prepared  by  heating  amidoazobenzene  with 
aniline  to  160°  C. 

Induline,  water  soluble  (Indigo  substitute),  is  the  sodium  salt  of  the  di- 
sulphonate  of  the  preceding,  and  is  extensively  used  for  silk  and  wool. 

Aiigrosine  is  prepared  by  heating  nitrophenol  with  aniline  and  aniline 
chlorhydrate.  The  alcohol  soluble  compound  is  the  simple  salt  of  the  base, 
while  the  sodium  sulphonate  forms  the  water  soluble  compound. 

Paraphenylene  Blue  is  a  dark  blue  dye  of  the  induline  class  obtained  by 
the  action  of  p-phenylene-diamine  upon  hydrochloride  of  amidoazobenzeue. 

Naphihyl  Blue  is  the  sodium  sulphonate  of  anilido-phenyl-naphthindu- 
line.  Dyes  silk  blue  with  a  red  fluorescence,  and  is  faster  to  light  than  the 
ordinary  indulines. 

(e)  ANILINE  BLACK. — For  the  preparation  of  aniline  black,  aniline 
chlorhydrate  is  very  carefully  oxidized.     The  dyestuif  is  not  prepared  for 
dyeing  or  printing,  but  is  fixed  on  the  fibre  by  an  oxidation  process  which 
develops  it  gradually.     It  is  a  very  fast  black.     Quite  a  variety  of  oxid- 
izing agents  may  be  used.     Potassium  chlorate  and  copper  sulphate  are 
frequently  used  in  admixture,  and  vauadate  of  ammonia  is  also  of  especial 
serviceableness  in  connection  with  the  chlorate.     Electrolysis  of  a  concen- 
trated solution  of  an  aniline  salt  will  also  produce  aniline  black. 


414  THE   ARTIFICIAL   COLORING  MATTERS. 

2.  PHENOL  DYE-COLORS. 

(a)  NITRO-DERIVATIVES. — PiGTiG  Acid  (Trinitrophenol)  is  made  by 
nitrating  carbolic  acid  direct  with  strong  nitric  acid,  or,  better,  by  acting 
upon  phenol-sulphonie  acid  with  strong  nitric  acid.  Forms  light  yellow 
leaflets  or  scales,  and  is  extensively  used  as  a  dye  for  silk  and  wool. 

Naphthol  Yellow  (Martins  Yellow,  Manchester  Yellow,  etc.)  is  the  so- 
dium, potassium,  or  calcium  salt  of  dinitro-a-naphthol,  and  is  prepared  by 
the  nitration  of  a-naphthol  either  directly,  or  after  conversion  into  the  mono- 
sulphonic  acid. 

Naphthol  Yellow  S  is  a  sulphonate  of  the  preceding,  and  is  made  by 
nitrating  the  a-naphthol-trisulphonic  acid.  The  color  is  faster  than  picric 
acid  or  the  simple  naphthol  yellow. 

Aurantia  is  the  ammonium  salt  of  hexa-nitro-diphenylamine,  and  is 
made  by  the  nitration  of  diphenylamine.  It  was  formerly  used  for  wool 
and  silk,  but  is  now  used  only  for  leather  coloring. 

(6)  ROSOLIC  ACIDS. — Rosolic  Acid  and  Aurin  (Pararosolic  Acid)  may  be 
prepared  from  rosaniline  and  pararosaniline  respectively  by  treatment  with 
sodium  nitrite  and  after  boiling  in  the  presence  of  sulphuric  acid.  These 
two  coloring  matters  are  no  longer  of  commercial  importance. 

Yellow  Corallin  is  prepared  by  heating  pure  phenol  with  concentrated 
sulphuric  acid  and  oxalic  acid  for  some  hours  until  the  evolution  of  gas 
nearly  ceases.  The  crude  product  of  the  reaction  obtained  by  pouring  the 
melted  mass  into  water  is  changed  into  the  commercial  dye  by  dissolving  it 
in  caustic  soda  solution  and  evaporation  to  dry  ness. 

Red  Corallin  (Paeonin)  is  obtained  by  the  action  of  ammonia  under 
pressure  upon  the  yellow  corallin,  and  represents  an  intermediate  product 
between  aurin  and  para-rosaniline. 

(c)  PHTHALEINS. — Phenol-phthalein  is  not  used  as  a  dyestuff,  but  as  an 
indicator  in  alkalimetry. 

Fluorescein  (Resorcin  Phthalein)  is  made  by  heating  molecular  propor- 
tions of  resorcin  and  phthalic  anhydride  to  195°  to  200°.  Fluorescein  is 
not  used  as  such  for  dyeing,  but  is  converted  into  the  eosins.  The  sodium 
salt  of  the  fluorescein  comes  into  commerce  under  the  name  of  uranine. 

Eosins. — The  several  halogen  substitution  derivatives  of  fluorescein 
form  the  class  of  dyes  known  as  eosins.  Thus,  the  potassium  or  sodium 
salt  of  tetrabrom-fluorescein  is  the  eosin  yellow  shade,  while  the  correspond- 
ing salts  of  tetraiodo-fluorescein  constitute  eosin  blue  shade.  Methyl  and 
Ethyl  Eosin  (Primrose)  are  the  methyl  and  ethyl  ethers  of  tetrabrom- 
fluorescein.  Aureosin  is  a  chlorinated  fluorescein.  Saffrosine  is  the 
potassium  or  sodium  salt  of  dibrom-dinitrofluorescein.  Erythrosin  is  the 
potassium  salt  of  di-iodo-fluorescein.  Rose  Bengale  is  the  sodium  salt  of 
tetraiododichlor-fluorescein.  Phloxin  is  the  potassium  salt  of  tetrabromdi- 
chlor-fluorescein,  and  Cijanosine  is  the  potassium  salt  of  the  methyl  ether 
of  phloxin.  Rhodamine  is  the  phthalein  of  diethyl-meta-amidophenol. 
Cyclamine  is  obtained  by  the  action  of  iodine  upon  thionated  dichlor- 
fluorescein.  Violamine  is  obtained  by  the  action  of  o-toluidine  upon 
fluorescein  chloride  and  sulphonation  of  the  product.  Wool  and  silk 
especially  are  dyed  with  the  eosins,  and  cotton  after  mordanting  with 
various  metallic  salts. 

Gallein  is  the  phthalein  of  pyrogallol,  and  is  prepared  by  an  analogous 
method  to  that  described  under  fluorescein.  It  is  very  little  used  in  dyeing, 
but  serves  for  the  preparation  of 


PRODUCTS.  415 

Ccerulein. — This  dye  is  obtained  by  heating  gallein  with  twenty  times 
its  weight  of  strong  sulphuric  acid.  Forms  a  dark  amorphous  mass,  which 
dissolves  in  alkalies  with  a  beautiful  green  color.  Coerulein  forms  a  color- 
less compound  with  sodium  bisulphite,  which  is  known  as  Coerulein  S,  and 
is  much  used  in  dyeing,  as  it  is  easily  decomposed  by  steaming. 

3.    NlTROSO    AND   OXYAZINE   COLORS. 

(a)  NITROSO  COLORS  (Chromophor  group  =  N  —  O'H.J.—Gambine  is 
obtained  by  the  action  of  nitrous  acid  upon  a-naphthol.  It  dyes  iron- 
mordanted  fabrics  green. 

Dinitrosoresorcin  is  obtained  by  the  action  of  nitrous  acid  upon  resorcin. 
Dyes  like  the  previous  color. 

Dioxine  is  obtained  by  the  action  of  nitrous  acid  upon  dioxynaph- 
thalene.  Dyes  bright  green  or  brown  shades  on  metallic  mordants. 

(6)  INDOPHENOLS   AND   INDAMINE   (Chromophor,  N  =  Oj. — Indo- 

phenol  (a-Naphthol  Blue)  is  prepared  by  oxidizing  dimethyl-paraphenylene- 
diamine  and  a-naphthol  with  bichromate  of  potash  and  acetic  acid.  Indo- 
phenol  may  be  reduced  by  glucose  and  caustic  soda  to  a  leuco-  compound 
known  as  Indophenol  white,  which  is  also  sold  commercially.  When  cotton 
goods  are  printed  with  leuco-indophenol,  the  blue  color  may  be  developed 
in  dilute  bichromate  of  potash  solution. 

Indamines  are  obtained  by  heating  the  indtilines  with  p-phenylene- 
diamine  and  p-phenylene-diamine  hydrochloride.  Dyes  deep  indigo-blue 
shades  on  cotton  mordanted  with  tannin  and  tartar  emetic. 

/  "7N\\ 

(c)  OXYAZINES    (Chromophor   /    \\. — Azurine  is  obtained  by  the 

action  of  nitrosodimethyl-aniline  hydrochloride  upon  sym-dioxybenzoic 
acid.  Dyes  a  violet  blue  on  chrome-mordanted  wool  or  cotton. 

Gallocyanine  is  obtained  by  the  action  of  nitrosodimethyl-aniline  upon 
gallic  acid.  It  is  a  gray  paste,  insoluble  in  water,  but  soluble  in  alcohol 
with  bluish-violet  color. 

Prune  Pure  is  the  methyl-ether  of  gallocyanine. 

Gallanilic  Indigo  is  the  sodium  bisulphite  compound  of  gallocyanine- 
anhydride-anilide. 

Meldola's  Blue  is  obtained  by  the  action  of  nitrosodimethyl-aniline  hy- 
drochloride upon  /3-naphthol.  Dyes  cotton  mordanted  with  tannin  and 
tartar  emetic  indigo-blue. 

Nile  Blue,  Capri  Blue,  and  Gallamine  Blue  are  all  oxyazine  colors 
obtained  by  analogous  reactions  of  nitrosodimethyl-aniline  or  the  cor- 
responding amidophenol. 

Resorcin  Blue. — By  the  action  of  nitrous  acid  upon  resorcin  is  pro- 
duced diazoresorcin,  which  by  the  action  of  concentrated  sulphuric  acid  is 
changed  into  diazoresorufin.  This  yields  a  hexabrom-  derivative,  the  am- 
monium salt  of  which  is  the  commercial  dye.  It  is  used  for  dyeing  silk 
and  wool  a  blue  color,  which  has  a  red  fluorescence,  especially  by  artificial 
light.  By  combining  with  yellow  dyes  it  yields  a  fluorescent  olive  color. 

/  -7N\\ 

(d)  THIAZINES   (Chromophor   /     \J. — Methylene  Blue  is  prepared 

from  dimethyl-aniline  by  the  treatment  of  this  first  with  sodium  nitrite  and 
then  with  hydrogen  sulphide  after  acidifying  with  hydrochloric  acid.  The 


416  THE   AKTIFICIAL   COLOKING   MATTERS. 

commercial  salt  is  a  zinc  double  chloride  of  the  sulphur  base,  called  tetra- 
methyl-thionin. 

4.  Azo  DYE-COLORS. — Chromophor  group,  — N  =  N — . 

A.  MONOAZO  DYES. — (a)  Amidoazo  Dyes. 

Chrysoidine  (Diamidoazobenzene  Hydrochloride)  is  obtained  by  ad- 
mixing solutions  of  diazobenzene  hydrochloride  and  m-phenylene-diamine. 
Forms  reddish-brown  crystals. 

Phenylene  Brown  (Bismarck  Brown,  or  Vesuvine)  is  triamido-azoben- 
zene  hydrochloride.  Forms  a  brown  powder  soluble  in  water. 

Suiter  Yellow  is  dimethylamidoazobenzene.  This  yellow  dye  is  soluble 
in  oils  and  is  much  employed  for  coloring  butter,  oils,  etc. 

Add  Yellow  (Fast  Yellow)  is  the  sodium  salt  of  the  disulphonic  acid 
of  aniline  yellow  (amidoazobenzene).  It  is  used  largely  in  dyeing  com- 
pound shades. 

Dimethyl-aniline  Orange  (Helianthin)  is  the  ammonia  salt  of  dimethyl- 
aniline-azobenzene-sulphonic  acid.  Dyes  silk  and  wool  a  fiery  orange.  It 
is  also  used  as  an  indicator  in  alkalimetry,  as  the  light  yellow  color  of  the 
solution  is  immediately  turned  red  by  the  addition  of  a  drop  of  hydro- 
chloric acid. 

Diphenylamine  Orange  (Tropseolin  GO,  Orange  IV)  is  formed  by  the 
action  of  diazobenzene-sul phonic  acid  upon  diphenylamine.  Dyes  silk  or 
wool  a  very  fine  golden  yellow. 

Metanil  Yellow  is  the  sodium  salt  of  phenylamidoazobenzene-m-sul- 
phonic  acid.  Forms  a  yellow  soluble  powder. 

Archil  substitute  (naphthion  red)  is  made  by  combining  p-nitraniline 
with  naphthionic  acid  or  /?-naphthylamine-sulphonic  acid. 

(b)  Oxyazo  Dyes. — Soudan  G  (Aniline-azoresorcin)  is  a  brown  powder 
hardly  soluble  in  water,  soluble  in  alcohol.  It  is  used  for  coloring  spirit 
varnishes,  oils,  etc. 

Soudan  Brown  (Pigment  Brown)  is  made  by  the  action  of  hydrochloride 
of  a-diazonaphthalene  upon  «-naphthol.  It  is  used  for  coloring  varnishes, 
soaps. 

Carmine-naphte  is  an  isomeric  compound  formed  from  /9-diazonaph- 
thalene  and  /3-naphthol.  Forms  a  red-brown  powder,  soluble  in  sulphuric 
acid  with  fuchsine-red  color. 

Alizarin  Yellow  is  a  yellowish-brown  dye  made  by  combining  p-nitr- 
aniline  with  salicylic  acid. 

Fast  Brown  N  (Naphthylamine  Brown)  is  made  by  combining  naph- 
thionic acid  with  «-naphthol.  Dyes  wool  brown  from  an  acid  bath. 

Crocein  Orange  (Ponceau  4GB)  is  prepared  from  hydrochloride  of 
diazobenzene  and  /?-naphthol-monosulphonic  acid.  It  is  a  fiery-red  powder, 
dyeing  a  reddish  orange  on  wool. 

Orange  G  is  the  sodium  salt  of  diazobenzene-£-naphthol-disulphonic 
acid.  It  dyes  an  orange-yellow  shade. 

Cochineal  Scarlet  2R  results  from  the  action  of  diazotoluene  upon  a-naph- 
thol-monosulphonic  acid.  It  forms  a  cinnabar-red  dye-color. 

Azococcin  2R  results  from  the  action  of  hydrochloride  of  diazoxylene 
upon  a-naphthol-sulphonic  acid.  It  forms  a  red-brown  powder,  difficultly 
soluble  in  water.  It  is  used  in  silk  dyeing. 

Wool  Scarkt  R  results  from  the  action  of  hydrochloride  of  diazoxylene 
upon  a-naphthol-disul phonic  acid.  It  forms  a  brown-red  powder,  soluble 
in  water  with  yellowish-red  color. 


PRODUCTS.  417 

Ponceau  2J2  (Xylidine  Red)  results  from  the  action  of  hydrochloride 
of  diazo-m-xylene  upon  /9-naphthol-disulphonic  acid.  It  forms  a  red  powder, 
easily  soluble.  It  has  been  used  in  large  quantities  as  a  substitute  for  coch- 
ineal. 

Ponceau  3R  (Cumidine  Red)  results  from  the  action  of  hydrochloride 
of  diazo-m-cumene  upon  /3-naphthol-disulphonic  acid.  It  is  used  as  the  pre- 
ceding, but  gives  redder  shades. 

Anisol  Red  and  Phenetol  Red  are  formed  by  the  action  of  anisidine  and 
amido-phenetol  respectively  upon  ^-naphthol-disulphonic  acid. 

Fast  Red  B  (Bordeaux  B)  is  formed  by  the  action  of  hydrochloride  of 
diazonaphthalene  upon  ^-naphthol-disulphonic  acid. 

a-Naphthol  Orange  (Tropaeolin  OOO,  No.  1)  is  the  sodium  salt  of  j9-sul- 
phanilic-acid-azo-a-naphthol.  Forms  orange-yellow  scales,  tolerably  solu- 
ble in  water.  It  dyes  silk  and  wool  a  reddish  orange. 

p-NapMhol  Orange  (Tropseolin  OOO,  No.  2,  Mandarin)  results  from  the 
action  of  jp-diazobenzene-sulphonic  acid  upon  /§-naphthol  in  alkaline  solu- 
tion. It  forms  an  orange-red  soluble  powder,  and  is  used  largely  for  wool- 
dyeing. 

Fast  Red  A  (Rocelline,  Cerasine,  etc.)  is  prepared  by  uniting  a-diazo- 
naphthalene-sul phonic  acid  acid  with  /9-naphthol.  It  forms  a  brown-red 
powder,  more  soluble  in  hot  than  in  cold  water.  It  is  used  largely  as  a 
substitute  for  barwood  and  orseille. 

Azorubin  S  (Fast  Red  C,  Carmoisin)  is  the  sodium  salt  of  the  disul- 
phonic  acid  of  naphthalene-azo-a-naphthol.  It  forms  a  reddish-brown 
soluble  powder. 

Brilliant  Ponceau  4R  (Cochineal  Red  A)  and  Fast  Red  D  (Amaranth) 
are  both  sodium  salts  of  trisulphonic  acids  of  naphthalene-azo-/2-naphthol, 
isomeric  with  each  other.  The  former  is  a  scarlet-red  easily  soluble  powder, 
the  latter  a  reddish- brown  powder. 

Roxamine  is  the  sodium  salt  of  dioxyazo-naphthalene-sul phonic  acid. 
It  dyes  wool  red  from  an  acid  bath  and  is  used  as  an  orchil  substitute. 

B.  DISAZO  DYES. — (a)  Disazo  Dyes  from  Azo  Dye-colors  (Primary 
Disazo  Dyes). — Resorcin  Brown  is  the  sodium  salt  of  a  sulphonic  acid  of 
resorcin-disazo-xylene-benzene.  Forms  a  brown  soluble  powder. 

Fast  Brown  results  from  the  action  of  two  molecules  of  a-diazo-naph- 
thalene-sulphonic  acid  upon  one  molecule  of  resorcin. 

Acid  Brown  G  is  formed  by  the  action  of  hydrochloride  of  diazo- ben- 
zene upon  chrysoidin-sulphonic  acid.  Dyes  wool  brown  in  acid  solution. 

Bismarck  Brown  is  the  hydrochloride  of  benzene-disazo-phenylene- 
diamine.  It  is  much  used  in  coloring  leather. 

(b)  Disazo  Dyes  from  Amido-azo  Dyes  (Secondary  Disazo  Dyes). — Cloth 
Red  G  (Azococcin  7B)  results  from  the  action  of  diazoazo-benzene  upon 
a-naphthol-sulphonic  acid.  Forms  a  brown  powder  not  readily  soluble  in 
water.  Used  in  wool-dyeing,  either  alone  or  in  connection  with  logwood, 
fustic,  etc. 

Brilliant  Crocein  (Cotton  Scarlet)  results  from  the  action  of  hydro- 
chloride  of  diazoazo-benzene  upon  /9-naphthol-disulphonic  acid.  Forms  a 
reddish  soluble  powder. 

Biebrich  Scarlet  (Ponceau  B). — It  is  the  sodium  salt  of  amido-azo-ben- 
zene-disulphonic-acid-azo-/?-naphthol.  Forms  a  brown-red  fairly  soluble 
powder.  Dyes  wool  and  silk  in  acid  bath  a  red  color  like  cochineal. 

Crocein  Scarlet  3B  (Ponceau  4RB)  results  from  the  action  of  diazoazo- 

27 


418  THE  AKTIFICIAL   COLORING  MATTERS. 

benzene-monosulphonic  acid  upon  /9-naphthol-monosulphonic  acid.  Forms 
a  red-brown  powder  dissolving  with  scarlet-red  color.  Used  in  wool-  and 
silk-dyeing. 

Bordeaux  G  is  obtained  by  the  action  of  amido-azo-toluene-mono- 
sulphonic  acid  upon  /3-naphthol-monosulphonic  acid  S.  Dyes  wool  red  from 
an  acid  bath. 

Ndphthol  Black  is  the  sodium  salt  of  the  tetrasulphonic  acid  of  naphtha- 
lene-disazo- naphthalene-/?- naphthol.  Forms  a  violet-black  powder.  Used 
exclusively  in  wool-dyeing. 

Wool  Black  is  the  sodium  salt  of  the  disulphonic  acid  of  a  benzene- 
disazo-benzene-p-tolyl-£-naphthylamine.  It  forms  a  bluish-black  soluble 
powder.  Dyes  a  deep  blue-black  color  and  is  quite  stable. 

Naphthylamine  Black  and  Anthracite  Black  are  obtained  by  the  action  of 
disulpho-naphthylene-azo-a-naphthylamine  upon  a-naphthylamine  and  di- 
phenyl-m-phenylene-diamine  respectively. 

Fast  Violet  is  the  sodium  salt  of  the  disulphonic  acid  of  a  naphthalene- 
disazo-benzene-/?-naphthol.  Forms  a  dark  brown  soluble  powder.  Used  in 
wool-dyeing. 

Chromatropes  2R,  2B,  6D,  etc.,  are  combinations  of  diazo  compounds 
with  dioxy-naphthalene-disulphonic  acid.  They  give  colors  varying  from 
scarlet  to  magenta,  which  on  subsequent  treatment  with  a  boiling  solution 
of  potassium  bichromate  change  to  very  fast  blacks. 

(c)  Disazo  Dyes  from  Diamido  Compounds  (Congo  Group,  or  Benzidine 
Dyes). — These  dyes  are  distinguished  from  all  other  coal-tar  dyes  by  the 
readiness  with  which  vegetable  fibres  may  be  dyed  with  them  without  pre- 
vious mordanting,  so  that  they  are  equally  applicable  to  vegetable  or 
animal  fibres,  and  can  be  used  with  goods  of  mixed  fibre.  They  are  often 
called  substantive  cotton  dyes.  Their  affinity  for  the  fibres  indeed  goes  so 
far  that  they  can  be  used  like  mordants  to  facilitate  the  fastening  of  other 
coal-tar  dyes  upon  the  vegetable  fibres. 

The  commercial  products  consist  generally  of  the  potassium,  sodium, 
or  ammonium  sulphonates  of  the  dye-color. 

Naphthalene  Red  is  the  sodium  salt  of  naphthalene-disazo-binaph- 
thionic  acid.  Dyes  unmordanted  cotton  red  from  a  boiling  alkaline  bath. 

Diamine  Gold  is  the  sodium  salt  of  disulpho-naphthalene-disazo- 
biphenetol.  It  dyes  unmordanted  cotton  yellow. 

Chrysophenine  is  the  sodium  salt  of  disulpho-stilbene-disazo-biphenetol. 
Dyes  like  the  previous  color. 

By  the  diazotizing  of  this  same  diamido-stilbene-disulphonic  acid  are 
also  derived  Hessian  Yellow,  Hessian  Purple  N  and  B,  and  Hessian  Violet. 

The  diazo  compound  from  the  molecule  of  benzidine  is  similarly  com- 
bined with  a  series  of  compounds  to  produce  the  well-known  benzidine 
dyes,  Congo  G  and  P,  Congo  Yellow,  Sulphanil  Yellow,  Brilliant  Congo  G, 
Cloth  Brown,  Diamine  Black,  Diamine  Blue,  Diamine  Scarlet,  Diamine 
Brown,  Diamine  Green,  and  Congo  Corinth  G. 

Congo  Red  is  the  sodium  salt  of  diphenyl-p-disazo-naphthionic  acid. 
Forms  a  reddish-brown  powder,  soluble  in  water  with  fine  red  color.  This 
solution  is  so  sensitive  to  acids  that  a  single  drop  of  very  dilute  sulphuric 
acid  suffices  to  convert  the  whole  of  the  liquid  to  a  beautiful  blue.  It  is 
therefore  a  valuable  indicator  in  volumetric  analysis. 

Benzopurpurin  is  formed  by  the  action  of  tetrazo-ditolyl  chloride  upon 
naphthylamine  sulphonate  of  soda.  It  is  a  dark  red  powder,  dissolving 


PEODUCTS.  419 

easily  in  water.  The  scarlet  obtained  from  this  dye  is  not  changed  by 
dilute  acid  as  is  that  from  Congo  red. 

Azo  Blue  is  formed  by  the  action  of  tetrazo-ditolyl  chloride  upon  /9-naph- 
thol-sulphonate  of  potash.  It  is  a  dark  blue  powder,  dissolving  easily  in 
water.  It  is  fast  to  acids  but  not  to  light. 

Diazotized  tolidine  yields,  besides  the  two  dyes  last  mentioned,  Delta- 
purpurin  55,  Chrysamine,  Azo  Blue,  and  Azo  Mauve.  Dianisidine  and 
diphenetidine  also  yield,  when  diazotized,  well-known  dyes  of  this  class, 
such  as  Benzoaurine,  Heliotrope,  and  Benzo-indigo-blue. 

Carbazol  Yellow  and  Naphihol  Blue-black  are  also  colors  of  this  class. 

Supplementary  to  the  Azo  Dyes. —  Tartrazin  is  formed  by  the  action  of 
two  molecules  of  phenyl-hydrazin-p-sulphonic  acid  upon  one  molecule  of 
dioxytartaric  acid.  Orange-yellow  powder,  easily  soluble  in  water.  It  is 
a  valuable  woollen  dye,  very  fast  to  light  and  fulling. 

Primuline  and  Ingrain  Colors. — Primuline  is  mentioned  here  because 
of  its  ready  convertibility  into  azo  colors  (ingrain  colors).  It  is  the  sodium 
salt  of  the  sulpho-  acid  of  a  sulphated  amido-  compound,  and  is  formed  by 
the  action  of  sulphur  upon  jo-toluidine.  The  primuline  base  is  a  yellow 
powder,  very  soluble  in  hot  water,  and  dyes  unmordanted  cotton  direct  from 
a  neutral  or  alkaline  bath.  Its  great  importance,  however,  lies  in  the  fact 
that  as  the  sulpho-  acid  of  a  primary  amine  it  can  be  diazotized  (see  p.  403), 
and  then  is  capable  of  combining  with  the  whole  range  of  phenols  and 
amines  to  form  azo  colors.  These  operations  can  readily  be  carried  out 
upon  the  fibre,  whence  the  colors  so  obtained  have  been  called  ingrain 
colors.  This  diazotizing  and  developing  with  the  phenol  or  amine  may  be 
effected  upon  silk,  wool,  or  cotton  fibre  previously  dyed  with  the  primu- 
line base.  In  this  way  yellows,  oranges,  purples,  reds,  scarlets,  maroons, 
and  browns  are  produced. 

When  paranitraniline  is  diazotized  we  obtain  azo-p-nitraniline.  If 
sulphuric  acid  is  added  to  the  compound  so  formed  and  the  diazo  com- 
pound admixed  with  a  large  excess  of  salt,  the  sodium  sulphate  so 
produced  protects  the  diazo  compound  from  light,  even  in  the  dry  state, 
until  ready  for  use  in  the  dye-bath  for  dyeing  goods  padded  with  naphthols, 
naphthylamines,  etc. 

5.  QUINOLINE  AND  AcKioiNE  DYES. —  Quinoline  Yellow  is  the  sodium 
salt  of  quinoline-phthalon-sulphouic  acid.  It  forms  a  yellow  powder, 
soluble  in  water  or  alcohol  with  yellow  color.  Used  for  wool-  and  silk- 
dyeing. 

Flavaniline  is  obtained  by  heating  acetanilid  with  anhydrous  zinc  chlo- 
ride for  several  hours  to  250°  C.  The  commercial  salt  is  the  hydrochloride 
of  the  base  so  obtained.  Was  formerly  used  for  wool-  and  silk-dyeing, 
and  for  cotton  after  mordanting  with  tannin  and  tartar  emetic. 

Oyanine  (Quinoline  Blue)  is  prepared  by  treating  a  mixture  of  quino- 
line  and  lepidine  with  arnyl  iodide.  It  forms  a  fine  blue  color,  but  unstable 
to  light.  It  is  not  of  importance  in  textile  coloring,  but  is  used  in  the 
manufacture  of  orthochromatic  photographic  dry  plates. 

Quinoline  Red  is  obtained  by  the  action  of  benzo-trichloride  upon  a  mix- 
ture of  quinaldine  and  isoquinoline.  Is  also  employed  in  the  manufacture 
of  orthochromatic  photographic  plates. 

Acridine  Yellow  is  the  hydrochloride  of  diamido-dimethyl-acridine. 
Dyes  silk  greenish-yellow  with  green  fluorescence,  and  cotton  mordanted 
with  tannin  yellow. 


420  THE  ARTIFICIAL  COLOEING  MATTERS. 

Phosphine  (Chrysaniline)  is,  as  was  before  noted  (see  p.  397),  a  by- 
product in  the  manufacture  of  magenta,  but  is  probably  diamido-phenyl- 
acridine.  The  phosphine  of  commerce  is  the  nitrate  or  chlorhydrate  of  the 
base  chrysaniline.  Used  at  present  chiefly  in  silk-  dyeing. 

6.  ARTIFICIAL  INDIGO.  —  Artificial  iudigo  has  now  become  an  article 
of  commerce,  and  in  purity  and  uniformity  distinctly  excels  the  natural 
product.  The  first  important  synthesis  was  that  utilizing  what  is  known  as 
"  propiolic  paste,"  which  is  a  moist  paste  containing  a  definite  percentage 
(usually  twenty-five  per  cent.)  of  o-nitrophenyl-propiolic  acid  prepared  from 
synthetic  cinnamic  acid.  Professor  Baeyer  found  that  this  o-nitrophenyl- 
propiolic  acid  when  in  alkaline  solution  is  readily  changed  by  reducing 
agents,  like  grape-sugar,  milk-sugar,  sulphides,  sulphydrates,  and  espe- 
cially by  xanthogenate,  into  indigo-blue.  The  reducing  agents  act  already 
in  the  cold  in  either  aqueous  or  alcoholic  solutions.  This  "propiolic 
paste"  was  used  for  a  time  in  calico-printing,  being  printed  on  the  goods 
along  with  the  reducing  agent,  but  the  decomposition  of  the  xanthogenate 
of  soda  develops  mercaptan,  the  unpleasant  odor  of  which  adheres  very 
persistently  to  the  goods,  and  the  blue  color  is  slightly  gray  in  shade.  It 
has  therefore  been  given  up  for  the  present. 

Kalle's  artificial  indigo  (due  to  Baeyer  in  conjunction  with  Drewsen)  is 
prepared  by  converting  o-nitrobenzaldehyde  into  o-nitrophenyllacto-ketone 
by  the  action  of  acetone.  The  product  of  the  reaction  is  then  changed  to 
a  soluble  compound  by  treatment  with  sodium  bisulphite,  and  is  sold  under 
the  name  of  "  indigo  salt."  This  salt,  if  dissolved  in  water  or  thickened 
with  any  suitable  substance  and  afterwards  applied  to  woollen  fabrics  and 
these  passed  through  a  solution  of  caustic  soda  of  20°  B.,  causes  the  full 
color  of  iudigo  to  develop. 

Following  these  syntheses  comes  that  of  Heumann  from  phenyl-glyco- 
coll,  which,  when  fused  with  caustic  alkali,  yields  pseudo-indoxyl,  and  this 
is  easily  changed  into  indigo  by  atmospheric  oxidation. 

Similarly,  phenyl-glycocoll-o-carboxylic  acid  (from  chloracetic  and  an- 
thranilic  acids),  heated  with  caustic  alkalies,  yields  the  same  results. 

This  last  synthesis  of  Heumann  and  that  of  Baeyer  and  Drewsen,  men- 
tioned above,  are  the  two  which  are  now  commercially  carried  out. 


/  \ 

7.  OXYKETONE  COLORS  f  Chromophor       II      J. 


(a)  ANTHRAQUINONE  DERIVATIVES.  —  Alizarin.  —  This  term  may  be 
applied  commercially  to  the  pure  dioxyanthraqtiinone  found  in  the  madder- 
root  and  made  artificially  from  anthraquinone-monosulphonic  acid,  or  to  the 
two  trioxyanthraquinoues  obtained  from  anthraquinone-disulphonic  acid, 
and  known  more  accurately  as  anthrapurpurin  and  flavopurpurin.  The 
first  or  true  alizarin  is  the  blue  shade  alizarin.  This  is  a  yellow  powder 
coming  into  commerce  as  a  ten  per  cent,  or  twenty  per  cent,  paste.  When 
dried  and  sublimed  it  forms  splendid  orange-red  crystals,  melting  at  280°  C. 
It  is  insoluble  in  water  and  sparingly  soluble  only  in  cold  alcohol.  Sulphuric 
acid  dissolves  it,  and  on  diluting  the  alizarin  is  precipitated  again  unchanged. 
It  acts  as  a  weak  acid,  and  forms  alizarates  with  the  alkalies  and  metallic 
hydrates. 

Anthrapurpurin  (Isopurpurin),  as  before  stated,  is  a  trioxyanthraqui- 
none,  but  is  generally  produced  along  with  the  preceding  compound  in  the 
manufacture  of  commercial  alizarin,  as  both  the  monosulphonic  and  the 


PRODUCTS.  421 

disulphonic  acids  are  obtained  in  sulphonating  anthraquinone.  Anthra- 
purpurin  is  obtained  in  the  purest  state  by  melting  pure  /?-anthraquinone- 
disulphonic  acid  with  caustic  soda  and  chlorate  of  potash.  It  melts  at 
360°  C. 

Flavopurpurin  is  obtained  also  in  the  manufacture  of  commercial  aliz- 
arin, and  can  be  prepared  as  sole  product  by  melting  «-anthraquinone- 
disulphonic  acid  with  caustic  soda  and  chlorate  of  potash.  Forms  orange- 
colored  needles,  melting  at  over  300°  C.  A  mixture  of  anthrapurpurin 
and  flavopurpurin  with  little  alizarin  constitutes  the  commercial  yellow 
shade  alizarin. 

Purpurin  is  also  a  trioxyanthraquinone,  but  differs  in  its  molecular  for- 
mula from  both  anthrapurpurin  and  flavopurpurin,  and  is  therefore  one  of 
three  isomers.  It  is  not  a  constituent  of  commercial  artificial  alizarin,  but 
is  found  accompanying  true  alizarin  in  the  madder-root.  It  forms  red 
needles,  beginning  to  sublime  at  150°  C.  and  melting  at  253°  C.  It  is 
soluble  in  boiling  water  with  dark-red  color. 

Alizarin  Bordeaux  B  is  a  tetraoxyanthraquinone,  and  is  made  by  oxi- 
dizing alizarin  with  fuming  sulphuric  acid  and  saponification  of  the  ether 
so  formed. 

Alizarin  Cyanine  R  is  penta-oxyanthraquinone  obtained  by  oxidizing 
the  alizarin  bordeaux  in  sulphuric  acid  with  manganese  dioxide  and  heat- 
ing the  intermediate  sulphuric  ether  with  dilute  acid.  Dyes  wool  mordanted 
with  alumina  violet,  with  chromium  blue. 

Alizarin  Orange  (Nitroalizarin)  is  formed  from  alizarin  by  the  action  of 
nitrous  acid,  or  by  the  action  of  nitric  acid  of  42°  B.  upon  alizarin  sus- 
pended in  glacial  acetic  acid.  It  forms  a  yellow  paste  of  twenty  per  cent, 
dry  material.  Aluminum  salts  form  an  orange  color,  chromium  salts  a 
brown-red  shade.  Used  with  silk,  wool,  and  cotton. 

Alizarin  Red  is  the  sodium  salt  of  alizarin-monosulphonic  acid,  and 
Alizarin  Maroon  is  amidoalizarin. 

Alizarin  Blue  is  a  dioxyanthraquinone-quinoline,  and  is  made  by  heating 
/J-nitroalizarin  with  glycerine  and  sulphuric  acid  to  90°  C.  Dark  blue 
powder,  almost  insoluble  in  water.  Hence  is  used  either  by  reduction  with 
zinc-dust,  grape-sugar,  or  similar  reducing  agent  and  subsequent  atmos- 
pheric oxidation,  as  in  indigo-dyeing,  or  by  forming  a  soluble  compound 
with  alkaline  bisulphites,  designated  as  Alizarin  Blue  S.  This  latter  is 
much  faster  to  light  than  the  original  color. 

Alizarin  Indigo-blue  8  and  Alizarin  Green  S  are  similar  sodium  bi- 
sulphite compounds, — the  first  of  penta-oxyanthraquinone-quinoline  and  the 
second  of  tri-  and  tetra-oxyanthraquinone-quinoline  and  their  sulphonic 
acids. 

Anthracene  Brown  ( Anthragallol)  is  a  trioxyanthraquinone.  It  is  formed 
by  heating  benzoic  and  gallic  acids  with  concentrated  sulphuric  acid,  or  by 
heating  pyrogallol  with  phthalic  anhydride  and  zinc  chloride.  It  comes 
into  commerce  as  a  dark  brown  paste,  and  yields  very  fast  shades. 

Ruffigallol  is  a  hexaoxyanthraquinone,  and  is  made  by  the  action  of  sul- 
phuric acid  upon  gallic  acid. 

(6)  Oxyketone  Colors  other  than  Anthraquinone  Derivatives. — Alizarin 
Yellow  A  is  made  by  the  condensation  of  benzoic  acid  with  pyrogallol,  and 
is  a  trioxybenzophenone,  while  Alizarin  Yellow  C  is  made  by  the  condensa- 
tion of  acetic  acid  with  pyrogallol  in  the  presence  of  zinc  chloride.  It  is 
a  gallacetophenone. 


422  THE  ARTIFICIAL   COLORING  MATTERS. 

Anthracene  Yellow  is  obtained  by  the  treatment  of  dioxy-/9-methylcou- 
marin  with  bromine. 

Alizarin  Black  8  is  the  sodium  bisulphite  compound  of  naphthazariue 
(dioxynaphthoquinone). 

Galloflavin  is  formed  by  the  atmospheric  oxidation  of  gallic  acid  in  alka- 
line solution.  Forms  a  dirty-yellow  paste,  insoluble  in  water  or  hydro- 
chloric acid.  Wool  mordanted  with  chromium  salts  takes  a  color  resembling 
that  obtained  from  fustic. 

8.  DYES  OF  UNKNOWN  CONSTITUTION. 

Cachou  de  Laval  is  obtained  by  the  fusion  of  organic  substances  such 
as  sawdust,  bran,  etc.,  with  sodium  sulphide.  It  dyes  cotton  brown. 

IV.  Analytical  Tests  and  Methods. 

In  this  section  it  is  not  the  intention  to  exhaust  the  subject  of  the  chemical 
examination  of  coal-tar  colors,  but  to  briefly  indicate  the  more  important  and 
characteristic  tests.  The  complete  chemical  analysis  of  the  artificial  organic 
dyes  is  very  seldom  resorted  to,  the  analyst  usually  determining  the  identity 
of  the  coloring  matter  by  means  of  the  tabular  schemes  which  have  been 
published  from  time  to  time  as  new  products  have  appeared  on  the  market, 
and  estimating  the  moisture  of  the  sample  and  such  foreign  substances  as 
the  sulphates  of  soda,  and  of  magnesia,  salt,  sugar,  starch,  and  dextrine, 
sand,  etc.  Of  considerable  value  in  connection  with  the  above  is  a  dyed 
sample  of  cloth  or  yarn,  which,  although  not  strictly  a  chemical  test,  is  one 
of  equal  importance,  especially  for  the  information  of  the  immediate  user 
of  the  dye.  The  recognition  of  dyes,  either  by  themselves  or  on  the  fibre, 
is  often  desirable,  but  this  requires  considerable  care  and  judgment,  from 
the  fact  that  a  very  large  number  are  simply  mixtures,  some  with  as  many 
as  five  separate  dyes ;  in  such  cases  the  task  is  almost  hopeless.  These  mix- 
tures are  sometimes  made  at  the  color  manufactory,  and  again  by  the  local 
agent ;  in  the  latter  case,  usually  to  supply  some  particular  shade  called  for, 
and  generally  without  any  regard  to  the  chemical  nature  of  the  constituents  ; 
this  indiscriminate  mixing  accounts  in  a  measure  for  the  streakiness  and 
uneven  effects  noticed  in  dyeing  piece  goods  and  yarn  with  such  colors, 
which  cannot  always  be  detected  by  dyeing  the  small  test  samples  in  the 
laboratory. 

Fastness  to  Light  is  determined  by  exposing  one-half  of  a  dyed  skein  or 
piece  of  dyed  cloth  to  the  action  of  direct  sunlight  for  a  definite  time,  say 
thirty  days  or  longer. 

Fastness  to  Soap. — A  piece  of  dyed  cloth  or  yarn  is  worked  in  a  neutral 
soap  lather,  washed,  dried,  and  compared  with  the  original. 

Comparative  Dye-trials. — For  this  purpose  vessels  of  glass,  porcelain,  or 
tinned  copper  are  most  convenient, — the  latter  is  the  best  suited, — and  if 
means  can  be  had  to  provide  heating  by  steam,  it  leaves  nothing  to  be  de- 
sired. When  several  comparative  dyeings  are  to  be  made  at  one  time  of  the 
same  class  of  samples,  one  equal  temperature  is  necessary. 

For  Wool  and  Silk. — In  either  case  it  is  best  to  use  a  vessel  containing 
about  one  litre.  From  twenty  to  twenty-five  grammes  of  wool  (yarn  or 
fabric)  and  about  five  to  ten  grammes  of  silk  answer  well  for  the  tests. 
The  quantity  of  dye  used  varies,  although  two  standards,  representing  one 
per  cent,  and  five  per  cent,  of  the  weight  of  the  wool  or  silk,  answer,  as  they 
give  two  shades  which  are  convenient  for  estimating  the  dyeing  value  of 


ANALYTICAL  TESTS  AND  METHODS.  423 

the  sample.  To  make  the  test,  the  color  is  weighed  out  carefully,  washed 
into  the  dye-bath  containing  water,  and  brought  to  the  boil,  into  which  the 
material,  previously  wetted  out,  is  immersed  and  kept  moving  about  for  a 
definite  time,  say  twenty  to  thirty  minutes,  or  until  the  bath  is  exhausted  of 
color,  when  it  is  withdrawn,  washed,  dried,  and  the  shade  compared  with 
a  swatch  of  the  same  weight,  treated  under  exactly  the  same  conditions  as 
to  temperature,  time,  etc. 

To  determine  the  relative  dyeing  values  of  color  samples,  two  solutions 
of  equal  value  are  made  of  equal  (known)  weights  of  the  dyes,  and  two 
dyeings  are  made  as  above,  only  adding  the  dye  solution  to  the  bath  as  fast 
as  it  is  taken  up  by  the  fabric ;  a  point  will  be  reached  when  no  more  color 
will  be  taken  up,  when  the  addition  must  stop,  the  difference  in  the  volume 
of  the  solution  remaining,  from  their  original  volume,  gives  the  amount  used 
in  each  test ;  and  as  the  strength  was  known,  the  relative  amounts  absorbed 
by  the  fabric  can  be  calculated.  The  above  applies  equally  to  silk.  No 
general  rule  can  be  given  which  will  embrace  the  application  of  the  colors 
to  fibres  in  testing,  reference  must  be  had  to  the  various  classes  of  dyes  and 
methods  in  Chapter  XIV. 

For  Cotton. — Few  colors  are  directly  applicable  to  this  fibre  without 
previously  mordanting  it  with  suitable  substances  which  will  cause  the 
color  to  remain.  In  the  laboratory,  a  quantity  of  cotton  is  taken  (yarn  or 
piece),  boiled  well  in  water,  and  immersed  in  a  five  per  cent,  solution  of 
tannin  for  about  twelve  hours,  when  it  is  removed  and  boiled  in  a  bath  con- 
taining two  and  a  half  per  cent,  of  tartar  emetic  for  thirty  to  forty-five 
minutes,  washed,  dried,  and  kept  for  use.  (Other  mordants — e.g.,  tin,  iron, 
alumina,  etc. — are  used  according  to  the  kind  of  work  done  in  the  estab- 
lishment.) In  the  matter  of  printed  goods,  swatches  of  cotton  cloth,  mor- 
danted on  one  piece  with  several  bases,  are  made  by  the  printer,  and  these 
are  then  passed  through  one  solution  of  color,  and  the  effect  can  be  conveni- 
ently noticed. 

For  Woollen  Yarn  Printing. — Pastes  are  made  up  of  the  color  in  vary- 
ing strengths  with  starch  or  flour,  and  with  such  assistants  as  may  be  re- 
quired, such  as  oxalic  or  tartaric  acids,  stannous  chloride,  etc.,  in  the  fol- 
lowing manner :  Five  grammes  of  color  are  taken  and  mixed  with  a  little 
water  containing  dextrine  or  glycerine,  and  this  is  made  up  to  five  hundred 
cubic  centimetres  with  a  paste  of  flour  (one  pound  per  gallon).  Twenty  or 
thirty  strands  of  yarn  about  a  metre  long  are  taken,  held  at  one  end,  and 
the  color-paste  rubbed  well  in  for  a  space  of  about  six  inches  with  a  glass 
rod  or  spatula ;  one-tenth  of  the  color-paste  is  emptied  out,  and  the  remain- 
ing is  diluted  again  to  five  hundred  cubic  centimetres,  and  this  is  then 
applied  to  the  yarn,  leaving  a  space  of  an  inch  or  so  from  the  first.  The 
diluting  operation  is  continued  so  that  the  printings  on  the  yarn  will  repre- 
sent color  in  the  proportion  of  1,  .9,  .8,  .7,  etc.,  giving  a  range  of  shades  of 
one  color.  The  yarn  so  printed  is  then  steamed  for  about  twenty  to  thirty 
minutes  under  pressure,  or  longer  without  pressure,  washed,  and  dried. 
This  method  is  of  much  value  in  matching  and  valuing  shades  in  tapestry 
carpets. 

By  Colorimetry. — This  method  involves  the  use  of  two  graduated  glass 
tubes,  closed  at  one  end,  each  of  the  same  diameter,  thickness,  and  length. 
The  standard  sample  of  dye  being  weighed  and  dissolved  in  water,  is  poured 
into  one  tube,  while  an  equal  weight  of  the  sample  to  be  tested  is  poured 
into  the  other,  and  by  holding  the  tubes  to  the  light  the  depth  of  color  is 


424 


THE  ARTIFICIAL   COLORING  MATTERS. 


seen.  If  one  is  darker  in  shade  than  the  other,  it  is  diluted  until  the  shades 
are  equal,  when,  by  knowing  the  number  of  cubic  centimetres  of  water 
added  to  equalize  the  tint,  the  relative  strength  of  the  dyes  can  be  ascertained. 

Mixtures  of  Dyes  can  be  detected  by  sprinkling  some  of  the  powder  on 
the  surface  of  distilled  water,  and  noticing  the  color  of  the  streaks  formed  as 
the  particles  subside,  or  by  dissolving  the  dye  in  a  little  alcohol  and  water  con- 
tained in  a  small  evaporating  dish  or  beaker,  and  immersing  therein  the  end 
of  a  strip  of  white  blotting-paper,  when,  in  the  case  of  mixtures,  several  dif- 
ferently-colored bands  are  seen  on  the  paper,  owing  to  the  fact  that  the  con- 
stituents of  the  mixture  do  not  always  possess  the  same  degree  of  capillarity. 
These  bands  can  be  cut  off  and  separately  tested  by  proper  reagents  according 
to  the  scheme  for  identification  of  dyes  following.  Fractional  dyeing  has 
also  furnished  information  of  value ;  usually  wool  or  silk  being  employed. 

Identification  of  Coal-tar  Dyes. — Weingartner's  comprehensive  tables, 
which  follow,  affords  means  of  determining  the  group  to  which  a  sample  of 
dye  under  examination  belongs.  The  dyes  are  divided  conveniently  into 
two  divisions,  basic  and  acid  coloring  matters,  and  the  latter  into  soluble 
and  insoluble  in  water. 

I.  The  Dye  is  Soluble  in  Water. — Add  a  few  drops  of  a  solution  of  tannin* 
to  a  solution  of  the  dye,  and  note  the  formation  of  a  precipitate,  after  heating. 

A.  Precipitation  takes  Place. — The  color  is  basic. — A  small  quantity  of 
the  original  color  is  dissolved  in  water,  and  reduced  with  hydrochloric  acid 
and  zinc-dust,  rapidly  filtered,  and  neutralized  with  sodium  acetate ;  small 
strips  of  filter-paper  are  immersed  in  the  solution,  and  exposed  to  oxidize. 


THE  ORIGINAL  COLOR  REAPPEARS  ON  THE  PAPER. 

The  original 
color  does  not 
reappear. 

Reds. 

Oranges  and 
yellows. 

Greens. 

Blues. 

Violets. 

FUCHSINE, 

PHOSPHINE, 

MALACHITE 

METHYLENE 

METHYL  VIOLET. 

CHRYSOIDINE. 

MAGENTA, 
ROSEINE. 

CHRYSANI- 
LINE.    With 

GREEN,    VIC- 
TORIA GREEN. 

BLUE.  With 
sulphuric 

Sulphuric  acid 
causes  a  yel- 

Color, orange. 
In  sulphuric 

With  sul- 

sulphuric acid, 

With  sulphuric 

acid,  green. 

lowish-brown 

acid,  dis- 

phuric add, 

reddish-yel- 

acid, yellow, 

Caustic  soda 

coloration  ;  on 

solves  to  a 

orown. 

low  precipi- 

on diluting 

causes  vio- 

dilution 

brownish- 

NEUTRAL  RED. 

tate.    Green 

with  water, 

let-black 

changes  to 

yellow  solu- 

With sul- 

fluorescence. 

green.  Ammo- 

precipitate. 

green  and  vio- 

tion. 

phuric  acid, 

Caustic  soda, 

nia  causes 

NEW  BLUE. 

let-blue. 

VESUVINE. 

green.   With 

light-yellow 

gray  or  red 

With  caustic 

NEUTRAL  VIO- 

Color, brown, 

caustic  soda 
solution,  yel- 

precipitate. 
Soluble  in 

precipitate. 
BRILLIANT 

soda,  blue- 
black  pre- 

LET. Sulphuric 
acid  causes 

upon  silk, 
orange.    In 

low-brown 

ether  with 

GREEN.    With 

cipitate. 

bright  violet 

sulphuric 

precipitate. 
SAFRANINE. 

green  fluores- 
cence. 

sulphuric  acid, 
same  as  above, 

MUSCARINE. 

Caustic  soda 

color  ;  on  dilu- 
tion changes 

acid,  soluble 
to  a  pale 

With  sul- 

FLAVANILINE. 

color  reap- 

causes 

to  blue. 

liquid. 

phuric  acid, 
green.  Caus- 
tic soda, 
brownish- 

With  sulphuric 
acid,  dirtv  yel- 
low precipi- 
tate.  Soluble 

pears  slowly. 
Ammonia,  lit- 
tle or  no  pre- 
cipitate. 

brownish- 
red  precipi- 
tate.   With 
tannin, 

MAUVEINE. 
Sulphuric  acid 
causes  gray 
color;  on  dilu- 

AURAMINE. 

Color,  yellow. 
With  alkalies, 
white  pre- 

red precipi- 

in ether  with 

METHYL  GREEN, 

indigo  -blue 

tion  changes 

cipitate. 

tate. 

blue  fluores- 

PARIS GREEN. 

precipitate. 

to  light  blue 

On  warming 

PYRONINE. 

cence. 

With  sulphuric 

CAPRI  BLUE. 

and  violet-red. 

with  sul- 

ACRIDINE 

ACRIDINE  YEL- 

acid, same  as 

MELDOLA'S 

AMETHYST. 

phuric  acid, 

RED. 

LOW. 

above,  color 

BLUE. 

Sulphuric  acid 

solution  de- 

TOLUYLENE 

ACRIDINE 

not  reappear- 

METAPHENYL- 

gives  green 

colorized 

RED 

ORANGE. 

ing  on  dilu- 

ENE BLUE. 

color;  blue  on 

VICTORIA 

tion.  Ammonia, 

INDAMINES. 

dilution. 

BLUE.  Color, 

solution  de- 

PRUNE. 

blue.     In  sul- 

composed, no 

PARAPHENYL- 

phuric  acid, 

precipitate. 

BNE  VIOLET. 

Drown  ish- 

AZINE  GREEN. 

red,  changes 

to  bluish- 

green. 

*  Twenty-five  parts  of  tannin,  twenty-five  parts  of  acetate  of  soda,  and  two  hundred 
and  fifty  parts  of  water. 


ANALYTICAL  TESTS   AND   METHODS. 


B.  No  Precipitation  takes  Place. — The  color  is  acid. 


425 


426 


THE  ARTIFICIAL  COLORING  MATTERS. 


II.   The  Dye  is  Insoluble  in  Water. — Treat  with  a  five  per  cent,  solution 
of  caustic  soda. 


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ANALYTICAL  TESTS  AND   METHODS.  427 

Chemical  Analysis  of  Dyes. —  Ultimate  analysis  is  not  within  the  scope 
of  this  work.  Proximate  analysis  is  constantly  resorted  to,  and  embraces 
the  determination  of  the  moisture,  mineral  matter,  salts,  starches,  etc. 

Determination  of  Moisture. — One  to  three  grammes  of  the  coloring 
matter  are  weighed  in  a  shallow  porcelain  or  platinum  dish,  and  exposed  to 
a  temperature  of  100°  to  105°  C.  in  an  air-bath,  allowed  to  cool  in  a  desic- 
cator, and  weighed  again,  the  difference  is  moisture. 

Insoluble  Matter. — The  dried  residue  from  the  above  is  dissolved  in 
water,  warmed  to  facilitate  solution  if  necessary,  and  filtered  through  a 
small  tared  filter,  washed  until  no  color  remains,  dried,  cooled  in  a  desic- 
cator, and  weighed.  If  dextrine  is  present,  it  will  be  noticed  in  this  test 
by  its  odor. 

Sodium  Chloride  (Common  Salt). — This  is  usually  determined  by  nitrate 
of  silver,  but  as  many  dyes  contain  chlorine  in  the  molecule,  the  addition 
of  this  reagent  directly  to  the  solution  is  inadmissible.  Salt  can  be  esti- 
mated indirectly  by  calculating  from  the  amount  of  chlorine  found  in  the 
ash  left  upon  igniting  some  of  the  dye  by  dissolving  in  water,  filtering  to  re- 
move any  insoluble  matter,  acidulating  with  a  few  drops  of  nitric  acid,  and 
adding  nitrate  of  silver  to  complete  precipitation.  Then  boil  for  a  few  minutes, 
and  filter,  wash  well  with  warm  water,  dry  on  the  filter,  remove  the  pre- 
cipitate carefully,  and  ignite  the  filter  separately,  when  cool  add  one  or  two 
drops  of  nitric  acid  and  a  drop  of  hydrochloric  acid,  ignite  again,  and  add 
the  main  bulk  of  the  precipitate,  and  ignite  until  the  edges  begin  to  fuse, 
cool  in  a  desiccator,  and  weigh  the  chloride  of  silver,  from  which  can  be 
calculated  the  percentage  of  salt.  Allen  states  that  chlorine  so  found 
probably  existed  originally  in  the  dye  as  common  salt.  Another  method, 
which  does  not  answer  in  every  case,  is  to  acidulate  an  aqueous  solution  of 
a  known  weight  of  the  dye  with  sulphuric  acid,  agitate  with  several  changes 
of  ether  until  all  the  color  has  been  taken  up  from  the  aqueous  solution  in 
which  the  salt  remains,  separated  by  a  tap-funnel,  when  it  can  be  precipi- 
tated and  estimated  as  usual. 

Sulphate  of  Sodium  (Glauber's  Salt)  in  the  anhydrous  condition  is  an 
admirable  adulterant  for  light-colored  dyes.  By  adding  a  hot  solution 
of  barium  chloride  to  an  acidulated  (hydrochloric  acid)  solution  of  a  dye 
which  is  sulphonated,  and  contains  an  admixed  sulphate,  a  precipitate  of 
barium  sulphate  and  barium  sulphonate  will  be  formed,  this  is  filtered  and 
well  washed  with  water,  and  treated  with  a  solution  of  ammonium  carbonate, 
the  sulphonate  will  be  converted  into  barium  carbonate  by  decomposition ; 
upon  adding  dilute  hydrochloric  acid,  the  carbonate  dissolves  while  the  sul- 
phate will  remain  unchanged,  wash  with  warm  water,  dry,  detach  from  the 
filter,  ignite,  and  weigh. 

Sulphate  of  Magnesia  (Epsom  Salt). — This  body  is  to  a  considerable  ex- 
tent employed  as  an  adulterant,  and  as  magnesium  is  never  a  chemical  con- 
stituent of  tar-dyes,  its  presence  in  the  ash  is  conclusive.  The  estimation 
is  carried  out  by  igniting  the  dye,  dissolving  in  dilute  hydrochloric  acid, 
filtering  if  necessary,  adding  ammonium  chloride  and  a  slight  excess  of 
ammonium  hydrate,  and  finally  a  solution  of  sodium  ammonium  phosphate, 
stirring,  care  being  taken  to  prevent  the  glass  rod  used  from  rubbing  the 
sides  of  the  beaker,  and  allowing  to  stand  overnight,  filter,  wash,  dry,  ignite, 
and  weigh  as  magnesium  pyrophosphate. 

Carbonates. — Indication  of  presence  by  effervescing  upon  addition  of  a 
dilute  acid.  Estimated  by  use  of  one  of  the  forms  of  carbonic  acid  apparatus. 


428  THE  ARTIFICIAL  COLORING  MATTERS. 

Dextrine. — This  substance  is  estimated  by  weighing  one  or  two  grammes 
of  the  dye  in  a  small  tared  beaker,  provided  with  a  glass  rod.  The  dye 
is  dissolved  in  a  little  water,  and  absolute  alcohol  added,  when  the  dextrine 
will  be  thrown  down,  and  adheres  closely  to  the  glass.  The  contents  are 
emptied,  and  the  glass  rinsed  two  or  three  times  with  alcohol,  dried,  and 
weighed. 

Starch. — The  presence  of  this  substance  must  not  be  taken  as  an  adulter- 
ant in  every  case  it  is  found  ;  owing  to  its  peculiar  properties  it  acts  as  a 
drier  or  absorber  of  moistness,  and  hence  prevents  the  caking  of  the  dye. 
By  dissolving  a  quantity  of  the  dye  in  water,  and  allowing  the  solution  to 
stand  in  a  conical  glass  for  a  while,  any  starch  present  will  subside,  the  clear 
liquid  is  poured  off,  and  the  residue  repeatedly  washed  with  distilled  water 
and  alcohol  until  no  color  remains,  it  can  then  be  examined  with  the  micro- 
scope ;  a  drop  is  placed  on  a  slide  with  a  drop  of  water,  the  cover-glass  put 
on,  and  a  drop  or  two  of  iodine  solution  placed  on  the  edge,  and  allowed  to 
displace  the  water  by  the  aid  of  a  piece  of  filter-paper  opposite  the  iodine, 
will,  if  starch  is  present,  develop  the  characteristic  reaction, — blue. 

Sugar. — Estimated  as  for  dextrine;  the  alcohol  used  should  be  satu- 
rated with  sugar.  Sugar  can  be  estimated  in  dyes  by  precipitating  the  col- 
oring matter  with  basic  acetate  of  lead,  and  proceeding  as  for  raw  sugar 
with  the  polariscope  (see  page  157),  or  by  inverting  and  estimating  with 
Fehling's  solution  (page  159). 

Sand  and  Iron  Filings  are  gross  adulterations  occasionally  met  with  in 
dyes  from  unprincipled  dealers.  Their  presence  would  have  been  noticed 
under  the  insoluble  matter,  determination.  Iron  filings  can  be  easily  deter- 
mined with  a  magnet. 

A  careful  microscopic  examination  of  ground  and  crystallized  dyes  will 
throw  much  light  on  their  preparation ;  bronze-powder  and  sugar  crystals 
have  been  thus  found. 

Paste-dyes,  etc.,  are  best  estimated  by  evaporating  a  weighed  quantity  to 
absolute  dryness  in  a  small  glass  mortar,  grind  thoroughly,  add  water, 
and  filter  through  a  tared  filter,  wash  with  water,  dry,  and  weigh.  If  this 
is  not  done,  trouble  will  be  met ;  paste-dyes  not  filtering  well  if  simply 
diluted  with  water. 

The  Examination  of  Dyed  Fibres  can  well  be  accomplished  by  the  aid 
of  the  following  table,  which  is  adapted  from  those  of  Hummell,*  of  R. 
Lepetit,f  and  of  Lehne  and  Rusterholz,|  and  embraces  a  majority  of  the 
more  important  coloring  matters  which  have  found  application.  The  re- 
agents employed  are  hydrochloric  acid  (HC1),  concentrated,  21°  Beaume",  and 
dilute,  one  part  of  acid  21°  B.  and  three  parts  water ;  sulphuric  acid 
(H2SO4),  concentrated,  66°  B.,  and  dilute,  one  part  of  acid  66°  B.  and  five 
parts  of  water;  nitric  acid  (HNO3),  concentrated,  specific  gravity  1.40, 
dilute  one  part  of  the  strong  acid  and  two  parts  of  water ;  caustic  soda  solu- 
tion (NaOH),  concentrated,  38°  B.,  and  dilute,  one  part  of  the  strong  solu- 
tion and  ten  parts  of  water;  ammonia,  specific  gravity  .960;  alcohol 
ninety-six  per  cent. ;  stannous  chloride,  tin  salt  (SnCl2  +  2H2O),  and  con- 
centrated hydrochloric  acid  equal  parts ;  acetate  of  ammonia  solution,  by 
neutralizing  ammonia  with  pure  acetic  acid  and  bringing  exactly  to  5°  B. 

*  Hummell,  The  Dyeing  of  Textile  Fabrics,  London,  1885. 

f  K.  Lepetit,  Journ.  Soc.  Chem.  Ind.,  vol.  viii.  p.  773  (from  Zeits.  f.  angew.  Chem., 
1888,  535).  j  Fiirber-zeitung,  1891,  Hefte  11,  13,  etc. 


ANALYTICAL  TESTS  AND  METHODS.  429 

The  initials  or  names  in  parentheses  following  the  names  of  the  dye-colors 
are  those  of  the  manufacturers  who  furnish  the  particular  dyestuff,  and  will 
be  readily  understood  by  those  accustomed  to  handle  these  wares. 

A  separate  column  has  not  been  made  for  nitric  acid,  but  where  its 
action  is  distinctive  it  is  noted  under  the  head  of  remarks. 

Method  of  Procedure. — For  the  testing  with  concentrated,  acids  and 
caustic  alkalies  small  watch-crystals  are  most  advantageously  used.  These 
are  then  placed  upon  white  paper  in  order  to  be  able  to  observe  carefully 
the  changes  of  color.  The  concentrated  acids  are  most  conveniently  dropped 
from  small  dropping  tubes  or  pipettes,  so  that  they  can  be  added  drop  by 
drop  until  the  fibre  is  completely  covered.  After  addition  of  the  acids 
four  to  five  minutes  are  allowed,  and  the  action  is  then  noted.  The  watch- 
crystals  are  then  heated  carefully  by  using  a  very  small  flame  or  placing 
them  upon  a  steam-coil,  but  the  liquids  upon  the  watch-crystals  should  not 
be  allowed  to  boil.  After  waiting  a  few  minutes  and  allowing  them  to 
cool,  water  is  added  to  the  contents  of  the  watch-crystals. 

All  the  other  reactions  of  the  tables  are  carried  out  in  test-tubes.  The 
fibre  is  placed  in  the  test-tube,  covered  with  the  reagent,  and  allowed  to 
stand  for  several  minutes,  then  heated  without  quite  bringing  the  liquids  to 
the  boiling-point,  when  the  action  is  carefully  noted.  Finally  the  liquids 
are  boiled  for  a  short  time.  The  solution  is  then  poured  off  and  caustic 
alkali  or  acid,  as  the  case  may  be,  is  added,  and  any  change  carefully  noted. 
After  the  tests  with  concentrated  hydrochloric  or  sulphuric  acids  the  fibres 
are  well  washed  with  water  in  order  to  observe  whether  the  original  color 
is  thereby  restored. 


430 


THE  ARTIFICIAL  COLORING  MATTERS. 


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BIBLIOGRAPHY  AND  STATISTICS.  439 

V.  Bibliography  and  Statistics. 

BIBLIOGKAPHY. 

1873.— Die  Farbstoffe,  P.  Schutzenberger,  uebersetzt  von  C.  Schroeder,  2te  Auf.,  2  Bde., 

Berlin. 
1878. — Die  Fabrikation  der  Anilinfarbstoffe,  etc.,  J.  Bersch,  Leipzig. 

Die  Theerfarbstoffe,  ihre  Darstellung  und  Anwendung,  S.  Mierzinsky,  Leipzig. 
1879. — History  of  Aniline  and  Allied  Coloring  Matters,  W.  H.  Perkin,  London. 

Les  Matieres  colorantes  artificielles,  A.  Wurtz,  Paris. 
1880. — Lexikon  der  Farbwaaren,  F.  Springmiihl,  Berlin. 

Das  Anthracene  und  seine  Derivate,  G.  Auerbach,  2te  Auf.,  Braunschweig. 

Die  neuere  Entwickelung  der  Theerfarben-Industrie,  Dr.  R.  Meyer,  Braunschweig. 

Lehrbuch  der  Farbenfabrikation,  J.  G.  Gentele,  2te  Auf.,  Braunschweig. 
1881. — Die  Industrie  der  Theerfarbstoffe,  C.  Haussermann,  Stuttgart. 
1882. — Manual  of  colors  and  Dye-wares,  J.  W.  Slater,  London. 
1883. — Matieres  colorantes  et  les  Applications,  Girard  et  Pabst,  Paris.    ' 
1886. — Die  Chemie  des  Steinkohlentheers,  G.  Schultz,  2  Bde.,  2te  Auf.,  Braunschweig. 
1887. — Die  kiinstlichen  organischen  Farbstoffe,  P.  Julius,  Berlin. 
1888. — Die  Anilin-Farben  und  ihre  Fabrikation,  Karl  Heumann,  Ite  Theil,  Braunschweig. 

Fortschritte  der  Theerfarbenfabrikation,  P.  Friedlander,  Berlin. 

Die  Anilin-Farbstoffe,  A.  Kertesz,  Braunschweig. 

1889. — Sur  la  Constitution  de  la  Naphthaline  et  de  ses  Derives,  Reverdin  et  Noel  ting, 
Mulhouse. 

Die  Fabrikation  der  Theerfarbstoffe  und  ihre  Rohmaterialen,  "W.  Harmsen,  Berlin. 

Die  Technik  der  Rosanilinfarbstoffe,  O.  Miihlhauser,  Stuttgart. 

Histoire  scientifique  et  industrielle  du  Noir  d'Aniline,  Noelting,  Mulhouse. 

Die  Theerfarben  mit  riicksicht  auf  Schadlichkeit,  etc.,  Th.  Weyl,  Berlin. 
1890.— Die  organische  Farbstoffe,  R.  Mohlau,  Dresden. 

Les  Matieres  colorantes,  etc.,  C.  L.  Tassart,  Paris. 

Traite  pratique  des  Matieres  colorantes  artificielles,  A.  M.  Villon,  Paris. 
1891. — Tabellarische   Uebersicht  der  kiinstlichen   organischen   Farbstoffe,   Schultz   und 
Julius,  2te  Auf.,  Berlin. 

Fortschritte  der  Theerfarbenfabrikation,  etc. ,  2te  Abtheilung,  Friedlander,  Berlin. 

Carbolsaure  und  Carbolsaure  praeparate,  H.  Kohler,  Berlin. 
1892. — Anilinschwarz  und  seine  Anwendung,  Noelting  und  Lehne,  Berlin. 

Chemistry  of  the  Organic  Dye-stuffs,  R.  Nietzki,  translated  by  Collin  and  Rich- 
ardson, London. 

The  Coal-Tar  Colors  with  Reference  to  Injurious  Qualities,  Th.  Weyl,  translated 

by  Henry  Leffman,  Philadelphia. 

1893. — Ueber  die  Entwickelung  der  Theerfarben-Industrie,  H.  Caro,  Berlin. 
1894. — Systematic  Survey  of  the  Organic  Coloring  Matters,  Schultz  and  Julius,  English 
translation  by  A.  G.  Green,  London. 

Tabellarische  Uebersicht  der  kiinstlichen  organischen  Farbstoffe,  A.  Lehne,  Berlin. 

Tabellarische  Uebersicht  der  Naphthalin  Derivate,  Reverdin  und  Fulda,  Basel. 
1895. — Lehrbuch  der  Farbenchemie,  J.  G.  Georgievics,  Wien. 
1896. — Dictionary  of  the  Coal-Tar  Colors,  2d  ed.,  Hurst,  London. 

Fortschritte  der  Theerfarbenfabrikation,  P.  Friedlander,  3te  Theil,  Berlin. 

Traite  des  Matieres  colorantes  organiques  artificielles,  Leon  Lefevre,  2  tomes,  Paris. 
1897. — Chemie  der  organischen  Farbstoffe,  R.  Nietzki,  3te  Auf.,  Berlin. 

Bolley's  Handbuch  der  Chem.   Technologie,   Band  v.  ;  Die  Theerfarbstoffe,   bei 

Kopp,  R.  Meyer,  und  R.  Gnehm,  Braunschweig. 

1898. — Die  Anilin-Farben  und  ihre  Fabrikation,  K.  Heumann,  2te  Theil,  bei  Dr.  P.  Fried- 
lander,  Braunschweig. 

Tabellarische  Uebersicht  der  kiinstlichen  organischen  Farbstoffe,  A.  Lehne,  Ergan- 
zungs-band,  Berlin. 

Farbereichemische  Untersuchungen,  Paul  Heermann,  Berlin. 

Chemische  Technologie  der  Azofarbstoffe,  C.  Biilow,  2  Bde.,  Leipzig. 

Geschichte  und  Systematik  der  Indigo-Synthesen,  A.  Reissert,  Berlin. 
1899. — Les  Matieres  colorantes  azoiques,  G.  F.  Jaubert,  Paris. 

Fortschritte  der  Theerfarbenfabrikation,  P.  Friedlander,  4te  Theil,  Berlin. 
1900.—  Chemistry  of  the  Coal-Tar  Colors,  R.   Benedikt,  translated  by  Knecht,   3d  ed., 
London. 

The  Manufacture  of  Lake  Pigments  from  Artificial  Colors,  Francis  H.  Jennison, 
London. 


440  THE   ARTIFICIAL   COLORING  MATTERS. 

STATISTICS. 

1.  CRUDE  MATERIALS  OF  THE  COLOR  INDUSTRY. — Schultz  (Chemie 
des  Steinkohleutheers,  1900,  3d  ed.,  p.  9)  states  that  the  present  produc- 
tion  of  coal-tar  throughout  the  world  is  as  follows :    England,  660,000 
tons ;  Germany,  160,000  tons  ;  France,  80,000  tons ;  Belgium,  50,000  tons ; 
Holland,  30,000  tons;  America,  120,000  tons;  total,  1,100,000  tons. 

As  raw  material  for  the  alizarin  industry,  Germany  imported  in  1899 
4,365,200  kilos,  of  anthracene.  She  also  imported  in  the  same  year  3,775,- 
600  kilos,  of  naphthalene  and  3,968,100  kilos,  of  crude  carbolic  acid. 

The  German  exportations  of  products  of  this  industry  have  been  during 
recent  years : 

1897.  1898.  1899. 

Aniline  oil  and  salts,  metric  centners  .    .    .    .    91,779  123,603  122,754 

Aniline  and  similar  dyes-,  metric  centners  .    .176,389  197,123  227,046 

Alizarin,  metric  centners 86,408  93,205  95,869 

In  1898  the  value  of  the  aniline  colors  exported  was  given  as  72,000,000 
marks.  Of  this  amount  the  United  States  took  15,600,000  marks  ;  Eng- 
land, 14,600,000  marks ;  Austria-Hungary,  7,000,000  marks ;  and  Italy, 
4,500,000  marks.  (United  States  Consular  Eeports,  November,  1899, 
p.  380.) 

2.  ANILINE  AND  SIMILAR  DYE-COLORS. — The  following  is  the  esti- 
mated daily  production  of  aniline  : 

Pounds. 

England   .    .  5,000 

France  .    .    .  10,000  to  12,000  (two-thirds  exported  to  Germany  and  Switzerland). 
Germany  .    .  18,000 

The  value  of  the  aniline  and  similar  dyes  imported  into  England  and 
the  United  States  for  recent  years  has  been  as  follows : 

1896.          1897.          1898.          1899. 

England £485,003  £471,543  £519,293  £493,569 

United  States  .    .    .$3,072,915         $3,196,478         $3,689,214         $3,799,353 

3.  ALIZARIN. — The  importations  of  alizarin  into  the  United  States  and 
into  England  have  been  for  recent  years  as  follows : 

1896.         1897.         1898.         1899. 

England £256,344  £223,875         £219,766         £215,228 

United  States $994,230        $1,022,970         $886,332         $700,485 

Schultz  states  that  there  are  at  present  nine  alizarin- works  in  full  and 
continuous  operation,  of  which  six  are  in  Germany  and  three  in  England, 
while  three  other  alizarin-works  exist  which  are  closed  at  present. 


RAW  MATERIALS.  441 


CHAPTER  XIII. 

NATURAL   DYE-COLORS. 

I.   Raw  Materials. 

THE  raw  materials  to  be  described  here  are  a  series  of  vegetable  dyes 
coming  into  commerce  partly  as  compact  heart  woods  and  roots  and  partly 
as  masses  of  separated  coloring  matters,  together  with  a  few  dried  animal 
remains  yielding  coloring  matters.  We  shall  take  them  up  most  con- 
veniently in  groups  according  to  the  colors  yielded. 
A.  RED  DYES. 

1.  Brazil-wood  and  Allied  Woods  (syn.  Rothholz,  Bois  de  Bresif). — The 
various  species  of  Ccesalpinia  yield  woods  which  appear  to  contain  a  com- 
mon chromogen,  brasilin,  C16H14O5.     This  seems  already  in  the  wood  to  be 
changed  in  part  into  the  corresponding  coloring  matter,  brasitein,  C16H12O5. 
And  the  change  may  be  made  complete  by  oxidizing  the  alkaline  brasilin 
solution  in  the  air  or  by  acting  upon  a  hot  solution  of  brasilin  with  an  alco- 
holic iodine  solution.     Liebermann  and  Burg  ascribe  to  the  crystals  of  bra- 
silin the  formula  C16H14O5  -f-  H2O,  and  call  attention  to  the  fact  that  it  bears 
the  same  relation  to  hsematoxylin,  C16HUO6  (see  p.  448),  that  alizarin  bears 
to  purpurin.     The  best  known  varieties  of  the  wood  are  known  by  the 
following  special  names :  Pernambuco-wood,  from  Ccesalpinia  crista,  grown 
in  Brazil  and  Jamaica,  yellowish-red  in  the  interior,  becoming  red  and  red- 
dish-brown on  the  surface.      Brazil-wood,  from   Ccesalpinia  Brasiliensis, 
grown  in  Brazil,  as  well  as  the  Antilles  and  Bahamas,  is  brick-red  in  the 
interior,  becoming  brown-red  on  the  surface.     It  is  inferior  in  coloring  power 
to  Pernambuco-wood.      Sapan-wood,  from   Ccesalpinia  sappan,  grown  in 
Siam,  China,  Japan,  Ceylon,  and  the   Indian  Archipelago  is  somewhat 
lighter  in  color  than  the  other  varieties.     It  is  yellowish-red  in  the  interior 
and  bright  red  on  the  surface.     Lima-wood,  or  Nicaragua-wood,  from  Cces- 
alpinia bijuga,  is  grown  in  Central  America  and  the  north  coast  of  South 
America.      The  Santa-Martha-wood  of  Mexico   and  Peach-wood  are  by 
some  writers  considered  as  of  the  same  species  as  Nicaragua-wood,  and  by 
others  are  derived  from  Ccesalpinia  echinata.     They  have  a  dirty-red  color  in 
the  interior,  becoming  paler  on  the  surface.     Bahia-wood,  California-wood, 
and  Terra- Firma-wood  are  other  less  known  varieties  of  the  same  class. 

2.  Sandal-wood^  Caliatur-wood,  Bar-wood,  and   Cam-wood  (syn.  San- 
telholzj  Bois  de  Santal  rouge)  form  another  group  of  woods  which  are  alike  in 
many  particulars  and  contain  probably  the  same  coloring  matter,  santalin, 
C17H16O6.     They  differ  as  a  class  from  the  Brazil-woods  in  their  more  resin- 
ous characters,  and  are  often  known  as  "  close  woods"  in  contrast  to  the 
others  as  "  open  woods/'     The  Sandal-wood  (Red  Sanders),  from  Pterocar- 
pus  santalinuSy  is  grown  in  the  East  Indies,  Ceylon,  and  Madagascar,  and  is 
a  very  hard  and  heavy  wood,  dark  brown  on  the  surface  and  blood-red  in 
the  interior.     Caliatur-wood  comes  also  from  the  East  Indies,  and  though 
used  as  a  substitute  for  the  sandal-wood  is  considered  as  a  distinct  variety. 


442 


NATURAL  DYE-COLORS. 


Sandal-wood  is  said  to  contain  some  sixteen  per  cent,  of  santalin.  Bar- 
wood,  from  Baphia  nitida,  comes  from  Sierra  Leone,  Africa,  and  is  a  dark- 
red  wood,  containing  twenty-three  per  cent,  of  santalin.  Cam-wood  (or 
Gaban-wood)  is  supposed  by  many  to  be  the  same  as  bar- wood,  but  by  others 
is  ascribed  to  species  of  Pterocarpus.  It  comes,  like  bar-wood,  from  the  west 
coast  of  Africa.  Madagascar-wood  is  a  minor  variety  resembling  Caliatur- 
wood. 

3.  Madder  (syn.  Krapp,  Racine  de  Garance)  is  the  dried  and  broken  root 
of  the  Rubia  tinctorium  and  allied  species.  It  grows  wild  in  Asia  Minor, 
Greece,  and  the  Caucasus,  and  has  been  cultivated  in  France,  Alsace,  Silesia, 

FIG.  116. 


Hungary,  Holland,  etc.     The  appearance  of  the  plant  may  be  seen  from 
Fig.  116,  in  which  it  forms  the  right-hand  illustration. 

In  the  Levant,  the  five-  to  six-year-old  plants  are  plucked,  in  Europe, 
those  two  to  three  years  old.  While  the  Turkish  madder  (known  as  Lizari 
or  Alizari)  was  the  earliest  in  use,  the  French  variety  grown  in  the  neigh- 
borhood of  Avignon,  in  part  upon  marshy  soil  (palus)  and  in  part  upon 
soil  containing  lime  (rose£),  has  long  been  considered  the  best.  Other 
varieties  are  the  Dutch  or  Zealand  madder,  the  Alsatian,  the  Silesian,  and 
the  Russian  madder.  That  which  has  not  been  freed  from  the  brown  outer 
crust  before  grinding  is  inferior  to  that  which  has  been  so  freed,  and  which 
is  known  as  *'  crop-madder,"  while  the  impurest  variety,  obtained  by  grinding 
the  rootlets,  crusts,  and  woody  parts  of  the  roots,  is  called  "  ™^n^™o^,w  " 


RAW  MATERIALS.  443 

From  the  madder-roots  are  also  prepared  by  fermentation  and  filtration 
of  the  separated  dye-colors  the  commercial  extracts  known  as  "  madder 
flowers"  and  "  guarancine."  One  hundred  kilos,  of  madder  will  yield  fifty- 
five  to  sixty  kilos,  of  madder  flowers. 

The  tinctorial  value  of  the  madder  depends  upon  the  existence  of  the 
two  coloring  matters,  alizarin,  C14H8O4,  and  purpurin,  C14H8O5,  both  of 
which  have  been  mentioned  under  the  artificial  dye-colors  derived  from  an- 
thracene. (See  p.  420.)  These  are  not  found  free  in  the  growing  plant, 
but  combined  as  glucosides  and  other  compounds  easily  decomposable  by 
fermentation.  As  a  nitrogenous  and  soluble  ferment  erythrozym  is  present ; 
so  soon  as  the  solutions  of  madder  extract  are  exposed  to  the  air  the  rubery- 
thric  acid  (or  alizarin  glucoside)  is  decomposed  into  alizarin  and  dextrose 
and  the  pseudo-purpurin  (or  naturally  occurring  purpurin-carboxylic  acid) 
is  decomposed  into  purpurin  and  carbon  dioxide.  Two  other  anthracene 
derivatives  also  occur  in  madder,  both  probably  as  decomposition  products 
of  pseudo-purpurin,  munjistin,  C15H8O6,  and  xanthopurpurin,  C14H8O4  (the 
latter  of  which  is  isomeric  with  alizarin). 

The  importance  of  madder  and  madder  preparations  has  almost  entirely 
disappeared  with  the  development  of  the  artificial  alizarin  manufacture. 
The  colors  obtainable  from  alizarin,  isopurpurin  or  anthrapurpurin,  and 
flavopurpurin,  which  are  the  products  of  the  synthetical  methods,  have 
almost  entirely  replaced  those  formerly  obtained  from  madder. 

4.  Safflower  (syn.  Safflor,  Fleurs  de  Carthame)  consists  of  the  dried  flowers 
of  the  Carthamus  tindorius,  a  plant  first  grown  in  Egypt  and  the  East 
Indies,  but  now  grown  in  Asia  Minor,  Spain,  Alsace,  Austria,  and  Central 
Germany.     The  flowers  are  of  a  deep  reddish-orange  color,  and  contain, 
besides  a  yellow  coloring  matter  of  no  technical  value,  carthamin,  or  car- 
thamic  acid,  C14H16O7,  a  red  dye  of  considerable  importance  for  silk-  and 
cotton-dyeing.     It  forms  from  .3  to  .6  per  cent,  of  the  weight  of  the  flowers. 
"  Safflower  carmine'7  is  a  solution  of  the  carthamin  in  soda,  and  "  plate 
carthamine"  is  a  pure  preparation  of  the  dye  which  has  been  dried  in  crusts 
upon  glass  or  porcelain  plates.     The  most  important  commercial  varieties 
of  safflower  are  the  Egyptian,  which  is  the  richest  in  dye-color,  the  East 
Indian,  the  Spanish,  and  the  German.     Safflower  comes  from  Spain  and 
France,  the  production  having  amounted  in  recent  years  to  400,000  pounds. 
However,  it  is  now  almost  entirely  displaced  from  use  as  a  dye  by  the 
artificial  dyes. 

5.  Orseille,  or  Archil  (syn.  Orseille,  Persia,  Cudbear). — The  various  species 
of  lichens,  as  Rocella  tinctoria  and  Rocella  fuciformis  from  Angola,  Zanzi- 
bar, Ceylon,  and  Mozambique,  as  well  as  from  the  Azores  and  South  Amer- 
ican coast,  contain  a  mixture  of  phenols,  phenol-ethers,  and  phenol-acids, 
such  as  orcin  (or  orcinol),  erythric,  orcellinic  and  lecanoric  (or  diorcellinic) 
acids.     These  by  the  action  of  air  and  ammonia  yield  orcein,  contained  in 
the  orseille  (archil)  extract  as  a  red  dye,  and  on  drying  the  extract  the  cud- 
bear or  persio  as  a  reddish-violet  powder. 

Archil  extract  occurs  in  commerce  in  two  forms,  paste  and  liquor.  The 
solid  matter  consists  mainly  of  the  impure  orcein  in  combination  with  am- 
monia. Its  preparation  will  be  referred  to  later.  Cudbear  (or  Persio) 
differs  mainly  from  the  orseille  extract  in  being  free  from  all  excess  of 
ammonia  and  moisture  and  in  being  reduced  to  a  fine  powder.  An  illustra- 
tion of  the  orseille-yielding  lichens  is  given  in  Fig.  116  (see  preceding  page) 
in  the  lower  left-hand  figure. 


444  NATURAL   DYE-COLORS. 

6.  Cochineal  (syn.   Cochenille)  is  the  dried  female  insect  Coccus  Cacti, 
which  lives  and  grows  on  the  plants  of  the  Cactus  family,  especially  the 
"  nopal,"  or  Cactus  opuntia.     The  nopal-plant  is  indigenous  to  Mexico,  but 
is  also  cultivated  largely  in  Central  America,  the  Canary  Islands,  the  Island 
of  Teneriffe,  Algeria,  and  the  East  Indies. 

The  commercial  varieties  of  cochineal  are  known  as  the  silvery-gray  and 
the  black  cochineal.  These  varieties  are  apparently  produced  according  to 
the  method  adopted  for  killing  the  insects  when  they  are  swept  off  the  leaves 
of  the  nopal-plant.  If  killed  by  immersion  in  hot  water  or  by  steam  they 
lose  the  whitish  dust  with  which  they  are  covered  and  constitute  the  black 
variety  (zaccatila)  •  if  killed  by  dry  heat  in  ovens  this  dust  remains  and 
they  yield  the  silvery-gray  variety  (bianco.)  This  latter  is  considered  the 
better,  and  is  sometimes  simulated  by  dusting  the  black  variety  with  pow- 
dered talc,  gypsum,  barytes,  or  stearic  acid.  The  natural  gray  powder  is  a 
variety  of  wax  known  as  coccerin. 

The  coloring  matter  of  the  cochineal  is  carminic  acid,  C17H18O10,  and  may 
amount  to  fifteen  per  cent,  of  the  weight  of  the  dried  cochineal,  although 
Liebermann  states  that  the  average  is  from  nine  to  ten  per  cent.  Carminic 
acid  is  a  purple  substance  soluble  in  water  and  alcohol,  but  only  slightly  so 
in  ether.  Chlorine  readily  destroys  the  carminic  acid  and  nascent  hydrogen 
reduces  it  to  a  leuco  body,  which  again  becomes  red  on  exposure  to  the  air. 
Chemically  it  is  a  glucoside,  being  capable  of  decomposition  into  carmine- 
red,  CUH12O7,  and  a  sugar,  C6H10O5. 

Carminic  acid  dissolves  in  caustic  alkalies  with  a  beautiful  red  color,  forms 
purple  precipitates  with  barium,  lime,  lead,  and  copper,  and  a  fine  red  lake 
with  alumina.  A  decoction  of  cochineal  behaves  with  reagents  somewhat 
differently  from  a  solution  of  the  pure  carminic  acid  owing  to  the  presence 
of  phosphates,  tyrosine,  etc.  The  addition  of  alum  or  stannic  chloride  to 
it  yields  the  fine  red  pigment  known  as  "  cochineal  carmine."  This  as  well 
as  other  preparations  from  cochineal  will  be  referred  to  again  under  products. 
(See  p.  458.) 

7.  Kermes  (syn.  Kermes,  Alkermes)  is  a  corresponding  substance  to  coch- 
ineal, and  consists  of  the  dried  female  insects  Coccus  Ilicis,  which  burrow 
under  the  epidermis  of  the  leaves  or  young  shoots  of  the  kermes  oak 
(Quercus  cocci/era),  growing  in  the  south  of  France,  Spain,  and  Algeria. 
The  coloring  matter  of  the  kermes  insect  has  not  been  sufficiently  investi- 
gated ;  it  is  said  to  be  identical  with  that  of  cochineal.     It  is  not  used  any 
longer  in  dyeing. 

8.  Lac  dye  (syn.  Fdrberlack)  is  the  product  of  the  Coccus  Lacca,  an  East 
Indian  insect  which  lives  on  the  branches  of  the  fig  and  other  trees.     The 
female  insects  exude  a  resinous  substance  which  encloses  them  and  attaches 
them  to  the  twig.      This  constitutes  the  "stick-lac"   (see  p.  98),  which 
contains  about  ten  per  cent,  of  coloring  matter.     This  latter  may  be  ob- 
tained by  treating  the  stick-lac  with  carbonate  of  soda.     The  coloring  mat- 
ter of  lac  dye  has  been  studied  by  Schmidt,  who  terms  it  laccainic  acid, 
C16H12O8,  and  found  it  to  be  very  similar  to  carminic  acid  in  most  of  its 
reactions.     Many  writers  consider  the  two  to  be  identical. 

B.  YELLOW  DYES. 

1.  Old  Fustic  (syn.  Gelbholz,  Bois  jaune)  is  the  trunk  wood  of  Morus 
tincloria,  indigenous  to  the  West  Indies  and  South  America.  It  is  also 
yielded  by  the  Madura  tinctoria  and  Broussonetia  tinctoria.  The  wood  is 
hard  and  compact  and  has  a  pale  citron-yellow  color.  It  contains  two  col- 


RAW  MATERIALS.  445 

oring  principles,  morin,  or  moric  acid,  C15H  0O7,  which  occurs  in  the  wood 
combined  with  lime,  and  madurin,  or  moritannic  add,  C13H10O6,  both  of 
which  are  yellow  dyes  and  are  contained  in  the  commercial  extract.  . 

2.  Young  Fustic  (syn.  Fisetholz,  Bois  de  fustet)  is  the  bark-free  wood  of 
the  Rhus  cotinus,  a  variety  of  sumach  growing  in  the  Levant,  Spain,  Hun- 
gary, Tyrol,  and  Italy.     The  coloring  matter  is  stated  by  Schmidt  to  occur 
as  a  soluble  compound  of  Justin  and  tannic  acid.     Thisfustin  is  a  glucoside, 
and  is  decomposed  by  dilute  sulphuric  acid  into  fisetin,  C15H10O6,  and  iso- 
dulcite.     A  decoction  of  young  fustic  gives  a  fine  orange  color  with  alka- 
lies and  bright  orange  precipitates  with  lime  and  baryta-water,  stannous 
chloride  and  lead  acetate.     It  also  gives  a  fine  orange  color  with  alumina 
mordants. 

3.  Quercitron  is  the  crushed  or  rasped  bark  of  the  Quercus  nigra  or 
Quercus  tinctoria,  indigenous  to  North  America,  and  grown  also  in  Ger- 
many and  France.     It  forms  a  brownish-yellow  powder,  from  which  an 
extia.-t  is  also  made.     The  coloring  principle  is  querdtrin,  C2lH22O12,  a 
glucoside,  which   is  decomposed  by  dilute  sulphuric  acid  into   quercitin, 
C15H10O7,  and  isodulcite.     Besides  quercitin,  the  bark  contains  quercitan- 
nic  acid,  C17H]6O9.     Quercitin  is  difficultly  soluble  in  water,  but  easily 
soluble  in  alkalies  with  golden-yellow  color.     "  Flavine"  is  the  commercial 
name  of  a  preparation  of  quercitron  obtained  by  acting  upon  the  bark  first 
with  alkalies  and  treating  this  extract  with  sulphuric  acid ;  it  is  a  varying 
mixture  of  quercitrin,  quercitin,  and  isodulcite,  having  some  sixteen  times 
the  coloring  power  of  the  bark. 

Flavine  and  quercitron  bark  are  used  chiefly  for  dyeing  cottons  and 
woollens  with  tin  mordants. 

4.  Persian  Berries,  or  Avignon  Berries  (syn.  Gelbbeeren,  Graines  jaunes), 
are  the  dried  fruit  of  different  buckthorn  (Rhamnus)  species.     The  differ- 
ent commercial  varieties  are  the  Persian  (from  Rhamnus  amygdalinus  and 
Rhamnus  oleo'idus),  coming  from  Aleppo  and  Smyrna,  regarded  as  the  richest 
in  dye-color  and  the  best  in  use,  the  French,  or  Avignon  (from  Rhamnus 
infectoria  and  Rhamnus  saxatilis),  the  Levantine,  or  Turkish  (from  Rham- 
nus infectoria  and  Rhamnus  saxatilis),  and  the  Spanish  (from  Rhamnus 
saxatilis)  and  the  Hungarian  (from  Rhamnus  amygdalinus,  etc.). 

The  coloring  matter  of  the  Persian  berries  is  called  by  Liebermann 
xanthorhamnin,  or  chrysorhamnin,  and  is  a  glucoside,  yielding  under 
the  influence  of  dilute  acids  rhamnetin,  C16H12O7  (or  methyl-quercetin, 
C15HbO7.CH3),  and  isodulcite.  Persian  berries  are  used  for  yellows  on 
wool  and  cotton  with  alumina  or  tin  mordants. 

5.  Weld  (syn.  Wau,  Gelbkraut,  Gaude)  consists  of  the  leaves  and  other 
parts  of  the  Reseda  luteola,  a  variety  of  mignonette.     It  is  cultivated  in 
almost  all  parts  of  Europe,  notably  in  the  south  of  France,  Germany,  and 
England.     The  coloring  matter  is  known  as  luteolin,  C15H10O6,  and  forms 
yellow  crystals  of  silky  lustre,  insoluble  in  water,  soluble  in  alcohol.    It  dis- 
solves in  alkalies  with  deep  yellow  color.    It  is  used  especially  in  silk-dyeing. 

6.  Annatto  (syn.  Orlean,  or  Roucou)  is  prepared  from  the  fleshy  pulp 
of  the  seed-shells  of  the  Bixa  orellana,  indigenous  to  the  West  Indies  and 
South  America,  but  cultivated  also  in  the  East  Indies.     The  commercial 
annatto  forms  a  soft  reddish-yellow  paste  of  buttery  consistency,  or  some- 
times it  is  dried  in  hard  cakes.     It  contains  two  coloring  matters,  bixin, 
C28H34O5,  and  orellin,  the  former  of  which — the  more  important — is  a  red  dye 
and  the  latter  a  yellow.    The  bixin  dissolves  in  alkalies  with  yellow  color.   It 


446  NATURAL  DYE-COLORS. 

is  used  somewhat  in  silk-dyeing.  Orellin  is  as  yet  only  slightly  studied, 
and  is  considered  by  some  to  be  simply  an  oxidation  product  of  bixin.  By 
far  the  largest  amount  of  annatto  is  used  not  in  dyeing  but  in  coloring  but- 
ter and  cheese.  (See  p.  270.) 

7.  Turmeric  (syn.  Gelbwurz,  Curcuma)  is  the  tuber  of  the  Curcuma  tinc- 
toria  and  Curcuma  rotunda.  The  roots  are  usually  grayish-yellow  on  the 
exterior  but  deep  yellow  in  the  interior.  The  plant  is  indigenous  to  Cen- 
tral Asia.  The  varieties  of  it  are  the  Chinese,  Java,  and  Bengal,  of  which  the 
latter  is  considered  the  best.  The  coloring  principle  is  curcumin,  C14H14O4, 
which  acts  like  a  weak  acid.  The  pure  color  is  bright  orange-red,  but  it 
dissolves  in  alkalies  with  a  red-brown  color.  It  is  not  employed  alone  as  a 
dye-color,  but  is  used  in  wool-  and  silk-dyeing  for  compound  colors. 

C.  BLUE  DYES. 

1.  Indigo  (syn.  Indig-blau,  Indigo). — This  is  by  far  the  most  important 
of  all  the  vegetable  dyes.  It  has  been  known  from  very  early  times  in  the 
East,  but  was  not  introduced  into  Europe  until  the  sixteenth  century,  where 
its  use  was  at  first  prohibited  because  of  the  general  culture  of  the  woad, 
and  indeed  it  was  only  in  1737  that  its  employment  was  legally  permitted 
in  France.  However,  in  time  it  displaced  the  woad  almost  entirely,  so  that 
the  latter  is  used  now  only  in  a  few  special  cases. 

The  indigo-plant  is  an  Indigofera,  the  more  important  varieties  of  which 
are  the  Indigofera  tinctoria,  cultivated  in  India,  particularly  in  Bengal, 
Coromandel,  Madras,  Java,  and  Manila ;  the  Indigofera  Anil,  cultivated  in 
Guatemala,  Caracas,  Brazil,  and  the  Antilles ;  the  Indigofera  Argentea,  culti- 
vated in  Egypt,  Senegal,  and  the  Isle  of  France.  Of  lesser  importance  are 
the  Indigofera  disperma  and  the  Indigofera  pseudotinctoria,  both  cultivated 
in  the  East  Indies.  The  Indigofera  tinctoria  is  shown  in  Fig.  116  (see  p. 
442)  to  the  left  of  the  illustration  above.  The  indigo  dye  does  not  exist  as 
such  in  the  plant  but  as  the  result  of  fermentation,  whereby  the  naturally 
occurring  indican,  a  glucoside,  is  decomposed,  most  probably  according  to 
the  reaction : 

2C26H?1N017  +  4H20  =  CI6H10N202  +  6C6H10O6. 

Indican.  Water.          Indigo-blue.  Indiglucin. 

The  plants  are  cut  at  two  or  three  different  periods  in  the  year  when  they 
have  just  come  into  bloom.  They  are  at  once  packed  into  bundles  and  put 
into  the  soaking- vats  covered  with  water.  A  fermentation  here  ensues, 
which  is  completed  in  from  ten  to  eighteen  hours,  according  to  the  tempera- 
ture of  the  air  and  the  ripeness  of  the  plants.  When  the  supernatant  liquid 
has  taken  a  yellowish-green  color  and  has  a  pleasant  sweetish  taste,  the  fer- 
mentation is  stopped  and  the  liquid  is  run  oif  into  vats  placed  at  a  lower 
level.  Here  it  is  beaten  vigorously  with  sticks  or  paddles  for  from  one  and 
a  half  to  three  hours  by  men  who  enter  the  vats  for  the  purpose.  The  liquid 
is  changed  by  this  treatment  to  a  deep-blue  color  and  becomes  covered  with 
froth  of  like  color.  When  the  men  leave  the  vat  to  rest,  the  separated 
indigo  rapidly  settles,  and  in  some  two  to  three  hours  the  supernatant  liquid 
can  be  run  off  from  stopcocks  placed  in  the  side  of  the  vat  at  levels  above 
the  indigo  precipitate.  Milk  of  lime  is  often  added  to  hasten  the  settling 
of  the  separated  indigo,  and  more  recently  dilute  ammonia  has  been  used. 
The  addition  of  this  latter  reagent  is  said  to  increase  the  yield  of  indigo 
and  to  improve  its  quality,  as  it  contains  less  indigo-brown  and  resinous 
impurities.  The  thin  paste  of  indigo  and  water  is  then  drawn  off,  boiled 
to  prevent  subsequent  fermentation,  and  strained  through  a  sheet.  It  is 


RAW  MATERIALS.  447 

then  put  into  square  press-boxes  lined  with  cloth  and  provided  with  holes 
in  the  sides  and  bottom  for  thorough  drainage  of  the  indigo.  Pressure  is 
then  applied,  gentle  at  first  but  stronger  as  the  indigo  hardens  and  acquires 
a  firmer  consistency.  The  mass  is  then  cut  into  cubical  blocks,  which  are 
stamped  with  the  name  of  the  factory  and  put  on  shelves  in  the  drying- 
house  to  slowly  dry  out,  great  care  being  taken  to  avoid  drafts  of  air,  which 
might  cause  the  cakes  to  crack  in  drying.  Three  hundred  kilos,  of  indigo- 
plants  yield  an  average  of  one  kilo,  of  indigo.  The  commercial  product 
contains  from  twenty  to  eighty  per  cent,  of  the  indigo-blue  (averaging  about 
forty-five  per  cent.),  and  with  this  two  other  coloring  matters,  indigo- 
brown  and  indigo-red,  besides  indigo-gluten,  moisture,  and  a  variable 
amount  of  mineral  matter. 

The  commercial  varieties  of  indigo  are,  first,  the  Asiatic,  of  which  the 
Bengal  indigo  is  the  best,  followed  by  the  Java,  Madras,  Coromandel,  and 
Manila  varieties ;  second,  the  American,  of  which  the  Guatemala  is  the 
best,  followed  by  the  Caracas  and  the  Brazilian  varieties;  and,  third, 
the  African,  including  the  Egyptian,  Senegal,  and  Isle  de  France 
varieties. 

Indigo-blue  is  insoluble  in  water,  alcohol,  ether,  dilute  acids,  and  alka- 
lies, soluble  in  fuming  sulphuric  acid,  aniline,  nitrobenzene,  chloroform,  and 
glacial  acetic  acid.  It  may  be  sublimed  by  heat,  although  with  partial  de- 
composition when  the  sublimation  is  carried  out  at  ordinary  atmospheric 
pressure.  By  the  action  of  alkaline  reducing  agents  it  is  changed  to  indigo- 
white,  C16H12N2O2,  and  dissolved.  Upon  this  reaction  and  the  subsequent 
change  of  the  indigo  white  when  deposited  upon  the  textile  fibre,  by  atmos- 
pheric oxidation  back  again  into  indigo-blue,  is  based  the  use  of  indigo  in 
vat-dyeing.  (See  p.  484.)  Indigo  is  used  on  the  most  extensive  scale  for 
cotton-  and  wool-dyeing,  less  generally  for  silk. 

2.  Woad  (syn.  Waid,  Pastel). — The  leaves  of  the  Isatis  tinctoria  and 
Isatis  liAsitanica  moistened,  slightly  fermented,  and  then  compacted  and  dried 
into  balls  constitute  the  woad  of  commerce  and  furnish  an  additional  source 
of  indigo.     As  before  stated,  the  use  of  the  woad  for  dyeing  antedated  the 
use  of  the  indigo-plant,  and  the  cultivators  of  the  woad,  particularly  in 
Central  Germany,  long  fought  against  the  introduction  of  the  richer  tropical 
indigo-yielding  material,  but  in  vain.     The  woad-culture  is  still  carried  on 
in  different  parts  of  Europe,  particularly  in  France  and  Germany,  but  in 
small  degree  compared  with  its  former  development.     The  woad  contains 
only  .3  per  cent,  of  indigo  reckoned  on  the  weight  of  the  fresh  leaves,  or 
as  it  is  often  calculated,  one  hundred  kilos,  of  woad  have  the  same  color- 
ing power  as  two  kilos,  of  indigo.     The  woad  balls  improve  in  quality  by 
keeping   for   some   years,  the   best  variety   coming   from    the   south    of 
France  under  the  name  of  Pastel.     The  woad  is  rarely  used  by  itself  in 
dyeing  operations,  but  along  with  indigo  as  a  means  of  inciting  the  fer- 
mentation in  the  "  woad-vat"  process  of  dyeing. 

A  few  other  plants,  such  as  Polygonum  tinctoriurnj  indigenous  to  China, 
and  JEupatorium  tinctorium,  indigenous  to  Brazil,  have  been  found  to  contain 
indigo,  and  have  been  used  locally  for  blue-dyeing. 

3.  Logwood  (syn.  Blauholz,  Bois  de  Campeche). — This  is  the  heart- 
wood,  freed  from  bark  and  sap-wood,  of  the  Hcematoxylon  Campechianum, 
a  tree  indigenous  to  Campeachy  Bay,  Central  America,  but  grown  now  in 
various  parts  of  Central  and  South  America  and  the  West  Indies.     The 
commercial  -varieties    are    the   Campeachy,  Yucatan,  Laguna,   Honduras, 


448  NATURAL  DYE-COLOES. 

Jamaica,  St.  Domingo,  Monte  Christo,  Fort  Liberte",  Martinique,  and  Guade- 
loupe logwoods. 

Of  these,  the  first  commands  the  highest  price  on  account  of  the  large 
yield  of  coloring  matter  obtainable  from  it  and  the  readiness  with  which  it 
"  bronzes"  when  submitted  to  the  "  curing"  process.  The  wood  conies  in 
logs  or  sticks  of  smaller  size,  and  is  then  chipped  or  rasped  by  the  makers 
of  extracts,  who  sell  it  in  the  chipped  or  rasped  condition  as  well  as  in  the 
form  of  prepared  extract.  The  wood  has  a  dark-red  color  on  the  exterior  but 
is  yellowish-red  in  the  interior,  has  a  weak  odor  of  violets  and  a  peculiar 
sweetish  but  astringent  taste.  On  moistening  the  wood  or  chips  with  am- 
monia it  takes  a  dark-violet  color.  Logwood  contains  some  nine  to  twelve 
per  cent,  of  the  chromogen,  hcematoxylin,  C16H14O6,  which  is  present  in  the 
wood  partly  in  the  free  state  but  mainly  as  glucoside.  It  forms  colorless 
prismatic  crystals  difficultly  soluble  in  water,  easily  soluble  in  alcohol  and 
ether.  From  the  hsematoxylin  by  oxidation  in  the  presence  of  alkalies,  and 
particularly  ammonia,  is  produced  hcematein,  C16H12O6,  the  true  dye-color. 
This  forms  small  crystals  or  crystalline  scales  of  dark-red  color  and  greenish 
metallic  lustre,  which  show  plainly  upon  the  wood,  especially  after  the  fer- 
mentation or  curing.  It  is  difficultly  soluble  in  water,  alcohol,  and  ether. 
Hsematein  forms  a  crystalline  compound  with  ammonia,  C16HU(NH4)O6 
-f  H2O,  which,  however,  is  decomposed  by  acids  or  by  heating  to  130°  C., 
leaving  pure  hsematein.  Zinc  and  sulphuric  acid  readily  reduce  the  hsema- 
te'in  to  haematoxylin  again.  Logwood  is  used  on  an  extended  scale  in  dye- 
ing wool,  silk,  cotton,  and  leather.  It  is  used  for  deep  blues,  blacks,  and 
jointly  with  other  coloring  matters  for  composite  shades  of  color. 

4.  Litmus  (syn.  Lakmus,  Tournesol). — This  is  a  dyestuif  very  similar  in 
character  to  orseille  and  persio  (see  p.  443),  and  also  derived  from  the  class 
of  lichens.  For  its  preparation  the  same  lichens  may  be  used,  although  at 
present  the  different  species  of  Lecanora  serve  as  the  chief  material,  such  as 
Lecanora  orcina,  L.  dealbata,  L.pareUa,  which  occur  in  the  French  Pyrenees, 
and  the  Lecanora  tartarea,  occurring  in  Iceland  and  Scandinavia.  The 
lichens  are  allowed  to  ferment  after  the  addition  of  stale  urine  or  ammonia 
and  carbonate  of  potash.  When  the  mass  has  assumed  a  deep-blue  color, 
chalk  or  gypsum  are  added,  and  it  is  shaped  into  small  cubes  and  dried. 
The  coloring  matter  is  azolitmin,  C7H7NO4,  which  differs  by  one  atom  of 
oxygen  only  from  the  orcein  of  orseille  extract,  C7H7NO3.  It  acts  like  a 
weak  acid,  the  salts  of  which  are  blue  in  color  (the  potassium  compound 
existing  in  the  commercial  litmus),  and  which  when  set  free  by  acids  is 
reddish  in  color. 

D.  GREEN  DYES. 

We  have  practically  nothing  here  that  has  assumed  practical  value  as 
yet.  The  only  ones  needing  mention  at  all  are  : 

1.  Chlorophyll. — This  is  the  green  coloring  matter  of  fresh  vegetation, 
and  is  abundantly  present  in  nature,  but  it  has  not  been  found  possible 
hitherto  to  isolate  it  in  a  pure  state  adapted  for  use.     Schutz  has,  however, 
separated  it  from  the  yellow  coloring  matter  accompanying  it,  xanthophyll. 
It  is  stated  that  chlorophyll  forms  a  beautiful  green  color  with  zinc  as  mor- 
dant which  is  adapted  for  dyeing,  but  it  has  not  as  yet  been  used  in  practice. 

2.  LoJcao,  or  Chinese  Green,  is  a  green  pulverulent  deposit  from  the 
decoction  of  the  bark  of  Rhamnus  chlorophorus  and  Rhamnus  utilis,  both 
indigenous  to  China.     Kayser,  who  has  investigated  the  lokao,  states  that 
the  coloring  matter  is  lokaonic  acid,  C^H^O^,  which  is  combined  in  the 


PROCESSES  OF  TREATMENT.  449 

commercial  preparation  as  the  alumina  lake.     This  lokaonic  acid  is  decom- 
posed by  acids  into  lokanic  acid,  CggHggC^!,  and  lokaose,  an  inactive  sugar. 
Lokao  has  been  used  for  cotton-  and  silk-dyeing,  but  is  practically  displaced 
by  the  cheaper  artificial  colors. 
E.  BROWN  DYES. 

1.  Catechu  (or  Cutch). — -This  has  already  been  spoken  of  as  one  of  the 
raw  materials  of  the  tanning  industry.     (See  p.  322.)     It  finds,  however, 
an  equally  extended  use  in  dyeing  as  an  adjective  color.     The  explanation 
of  this  is  that  catechu  contains  two  principles,  catechin,  C21H20O9  -f-  5H2O, 
a  yellow  dye  forming  brown   precipitates  with  copper,  alumina,  and  tin 
mordants,  and  catechutannic  acid,  C13H12O5.    The  former  is  present  in  amount 
from  twenty  to  thirty  per  cent.,  the  latter,  however,  from  forty-eight  to 
fifty-two  per  cent.     The  best  variety  of  catechu  is  the  Pegu  catechu,  and 
after  this  the  Bombay  and  the  Bengal  catechu.     Catechu  is  extensively  used 
in  both  cotton-  and  silk-dyeing  for  browns  and  for  composite  shades. 

2.  Kino  is  a  natural  dyestuff  very  similar  to  catechu  and  comes  from 
a  variety  of  sources,  as  JSutea  frondosa  and  Butea  superba,  yielding  the  Ben- 
gal kino  ;  Pterocarpus  erinaceus,  yielding  the  West  African  kino ;  Eucalyp- 
tus corymbosa  and  other  Eucalyptus  species  yielding  the  Australian  kino. 
The  important  principles  are  Idndin,  CuHi2O6,  and  its  anhydride,  kino-red, 
CjgH^On.     It  is  used  like  catechu  for  dyeing. 

n.  Processes  of  Treatment. 

1.  CUTTING  OF  DYE-WOODS. — Whether  the  dye-woods  are  to  be  used 
for  the  manufacture  of  extracts  or  used  as  wood  by  the  dyer,  they  must  be 
reduced  to  powder  or  cut  into  chips  of  small  size.     This  process  varies  with 
different  manufacturers.     In  America,  it  is  usually  one  of  cutting  with 
powerful  knives,  in  which  whole  logs  are  brought  with  their  ends  against 
rapidly-revolving  cylinders,  on  the  circumference  of  which  are  heavy  steel 
knives,  which  cut  off  flat  chips  directly  across  the  grain  about  one-eighth 
inch  in  thickness.     This  method  is  a  very  rapid  one,  as  but  little  previous 
splitting  of  the  logs  is  necessary.     In  Europe,  where  labor  is  cheaper,  the 
logs  are  frequently  sawed  and  split  into  billets  about  two  feet  long  and  two 
to  three  inches  in  thickness,  and  these  are  then  brought  by  hand  diagonally 
against  toothed  knives  on  a  rapidly-revolving  cylinder,  by  which  means  the 
wood  is  torn  or  rasped  into  a  much  finer  condition,  or  these  billets  are  put 
into  a  machine  which  presses  them  in  this  way  against  the  revolving  knives. 
Such  a  machine  of  German  design  is  shown  in  Fig.  117,  where  a  rotating 
drum,  D,  carrying  on  its  circumference  a  series  of  knife-blades,  is  continu- 
ously cutting  the  billets  of  wood  which  are  pressed  against  it. 

2.  FERMENTATION  OR  CURING  OF  DYE-WOODS. — As  has  already  been 
stated  in  several  cases,  the  dye-woods  in  the  fresh  condition  contain  not  the 
finished  dye-color,  but  a  chromogen  capable  of  passing  into  the  former 
under  the  influence  of  oxidizing  or  other  agents.     Notably  is  this  the  case 
with  logwood,  and  the  chips  or  rasped  wood  are  therefore  submitted  to  a 
curing  treatment  by  moistening  them  with  water  and  exposing  them  to  the 
air  in  heaps  some  three  feet  in  depth  for  from  four  to  six  weeks.     The  chips 
heat  up,  and  the  pile  must  then  be  turned  with  shovels  to  regulate  the 
temperature  and  allow  contact  with  the  air.     More  water  is  then  added, 
and  the  process  continued  until  the  chips  assume  a  rich  reddish-brown  color 
or  become  coated  with  a  bronze  powder  (hsematein).     Various  chemicals 

29 


450 


NATURAL  DYE  COLORS. 


have  been  suggested  to  hasten  the  operation,  such  as  ammonium  carbonate 
and  chloride,  stale  urine,  sodium  carbonate,  potassium  nitrate,  chalk,  and 
glue.  None  of  these  are  known  certainly  to  be  of  benefit.  The  alkalies 
give  the  chips  a  fine  red  color  at  first,  but  unless  great  care  is  taken  they 
cause  them  to  become  black  from  over-oxidation  before  the  action  can  be 
checked.  Glue  has  been  used  because  it  is  said  to  combine  with  the  tannin 
of  the  wood,  and  by  removing  it  to  open  up  the  pores  of  the  wood  to  the 
oxidizing  influence  and  so  facilitate  the  curing.  But  the  existence  of  tannin 
in  logwood  has  not  been  at  all  certainly  established. 

FIG.  117. 


Curing  is  of  value  to  the  dyer  because  it  enables  him  to  rapidly  obtain 
the  color  from  the  chips  and  gives  him  a  liquor  containing  a  more  highly 
oxidized  coloring  matter,  which  "goes  on"  the  goods  more  rapidly.  It 
must  be  remembered,  however,  that  curing  the  chips  enables  the  manufac- 
turer to  sell  twenty  to  thirty  per  cent,  of  water  with  them,  while  uncured 
chips  contain  ten  to  fifteen  per  cent,  of  moisture. 

When  the  chipped  logwood  is  intended  for  the  manufacture  of  extract  it 
is  usually  conveyed  directly  to  the  extractors  without  curing,  which  is,  no 
doubt,  the  better  procedure,  since  all  oxidation  in  the  first  part  of  the  process 
is  objectionable. 


PROCESSES  OF  TREATMENT. 


451 


3.  MANUFACTURE  OF  DYE-WOOD  EXTRACTS. — As  dye-woods  contain 
generally  only  a  tenth   or  less  of  their  weight  of  dye-color,  it  becomes  a 


FIG.  118. 


452 


NATURAL  DYE-COLORS. 


FIG.  119. 


matter  of  great  economy  in  transportation  and  storage  to  prepare  from  them 
extracts,  either  as  concentrated  liquids  or  solids  representing  the  active 
coloring  principle.  This  is  done  by  manufacturers  who  make  a  specialty 
of  this  extracting,  and  apply  to  it  the  best  designed  and  most  improved 
machinery. 

The  operation  may  be  divided  into  two  stages, — the  extraction  and  the 
concentration.  For  extraction  a  rasped  wood  such  as  is  made  in  France  has 
many  advantages  over  the  chipped,  since  it  yields  its  coloring  to  a  smaller 
quantity  of  water  and  at  a  lower  temperature  than  the  chips.  The  extrac- 
tion consists  in  heating  the  wood  with  water  under  various  conditions  and 

then  drawing  off  the  liquor  into  tanks  for 
settling  or  treatment.  The  conditions  refer 
to  the  kind  of  vessels,  the  amount  and 
quality  of  the  water,  and  the  temperature. 
Many  European  manufacturers  use  open 
wooden  vessels  for  extractors,  so  that  the 
temperature  does  not  get  above  100°  C. 
As  this  method  was  first  used  in  France,  it 
is  known  as  the  French  process.  The  use 
of  closed  extractors,  however,  allows  of 
increase  in  the  pressure,  and  this  within 
limits  much  facilitates  the  perfect  extrac- 
tion. A  closed  extractor  of  German  de- 
sign, in  which  a  pressure  not  exceeding 
two  atmospheres  is  used,  is  shown  in  Fig. 

118.  (See  preceding  page.)     It  will  be  seen 
that  the  vessel,  A,  is  provided  with  a  false 
bottom,  D,  to  allow  of  the  draining  off  the 
extract  liquor,  a  perforated  steam-pipe,  g, 
to  rapidly  bring  up  the  contents  of  the  ex- 
tractor to  the  required  temperature,  and  a 
drainage-pipe,  A,  to  draw  off  the  thin  ex- 
traction liquors. 

In  America  closed  copper  or  iron  ves- 
sels are  used,  arranged  in  battery  form  very 
much  like  the  diffusion  apparatus  now  used 
in  the  extraction  of  sugar.  One  cell  of 
such  an  extraction  battery  is  shown  in  Fig. 

119.  This  method  allows  of  continuous 
working,  as  one  cell  of  the  series  can  be 
emptied  of  exhausted  dye-wood  and  loaded 
with  fresh  chips  while  the  extraction  liquors 

are  passing  successively  through  the  other  cells  of  the  battery  and  ac- 
quiring the  maximum  strength.  The  temperature  or  pressure  varies  with 
different  manufacturers,  but  most  writers  on  the  subject  agree  that  a  press- 
ure not  exceeding  fifteen  to  twenty  pounds  excess  over  atmospheric  press- 
ure should  be  used.  An  increase  in  the  pressure  is  always  attended  with 
an  increase  in  the  yield,  and  after  a  certain  point  with  a  decrease  in  the 
coloring  value  of  the  resulting  extract.  When  the  liquors  from  the  ex- 
tractors are  run  into  large  tanks  and  allowed  to  cool  much  wood-fibre 
and  some  resinous  matter  separates.  The  clear  liquor  is  then  drawn 
into  the  evaporators,  which  in  this  country  almost  invariably  consist  of 


PROCESSES  OF  TREATMENT. 


453 


vacuum-pans,  but  in  Europe  often  consist  of  open  pans  or  vessels  in  which 
heated  disks  revolve  so  as  to  favor  the  evaporation.  While  the  liquor  is 
still  thin,  double-  or  triple-effect  pans  are  used,  and  of  recent  years  the 
Yaryan  evaporators  (see  Fig.  40,  p.  131)  have  been  applied  with  great  suc- 
cess to  the  evaporation  of  dye-wood  extracts.  As  the  liquors  become  thicker 
the  concentration  is  continued  in  vacuum-pans  more  analogous  to  the  strike- 
pans  of  the  sugar  refinery.  Such  a  vacuum-pan  designed  for  use  in  the 
manufacture  of  dye-wood  extracts  is  shown  in  Fig.  120.  When  the  gravity 

FIG.  120. 


of  the  liquid  becomes  42°  or  51°  Tw.,  it  is  drawn  off  into  barrels  for  ship- 
ment, or  if  the  solid  extract  is  desired  the  concentration  is  continued  in  a 
vacuum-pan. 

Various  methods  of  treatment  have  been  suggested  at  different  stages  of 
the  process  with  a  view  of  improving  the  extract,  but  it  is  an  open  question 
whether  anything  better  than  pure  water  has  yet  been  used.  The  addition 
of  solutions  of  glue  and  of  different  salts  to  the  wood  before  extraction  has 
been  frequently  recommended.  Chalk  suspended  in  water  and  dilute  lime- 


454  NATURAL  DYE-COLORS. 

water  have  also  been  recommended  to  be  similarly  used.  Such  processes 
could  only  result  in  an  over-oxidized  product.  Borax  has  also  been  used, 
but  without  notable  advantage  in  the  case  of  logwood,  although  it  serves 
very  well  in  the  case  of  the  redwoods.  The  use  of  chlorine,  hypochlorites, 
and  chlorates  has  been  patented  in  connection  with  logwood  extract  for  addi- 
tion either  to  the  wood  or  the  liquor  after  extraction,  but  it  is  doubtful  if 
any  of  these  are  used  on  a  large  scale  at  the  present  time.  That  these  sub- 
stances and  many  others  develop  the  color  of  logwood  there  can  be  no  ques- 
tion, but  to  be  of  value  to  the  dyer  that  development  must  take  place  in  the 
presence  of  the  goods. 

The  yield  of  logwood  extract  by  the  American  process  of  manufacture 
is  said  by  Soxhlet  *  to  be  twenty  or  twenty-one  per  cent,  of  solid  extract, 
while  that  by  the  French  process  is  sixteen  and  a  half  per  cent.  The  latter 
is  superior  in  quality,  and  is  therefore  almost  invariably  reduced  by  the 
addition  of  such  substances  as  molasses,  glucose,  and  extract  of  chestnut. 
In  America,  in  addition  to  the  above,  extract  of  hemlock  and  extract  of 
quercitron  (after  the  removal  of  the  flavine)  are  considerably  used  to  adul- 
terate logwood  extract. 

4.  MISCELLANEOUS  PROCESSES. — (a)  Preparation  of  Quarantine  and 
Madder  Flowers. — For  the  preparation  of  guarancine,  the  pulverized  mad- 
der-root is  warmed  gently  with  dilute  sulphuric  acid  (one  part  acid  and  two 
parts  water)  for  some  time,  whereby  the  glucosides  of  the  madder  are  de- 
composed. The  sugary  liquid  is  drained  off  and  the  residue  heated  with 
concentrated  sulphuric  acid,  which  decomposes  the  woody  fibre  and  other 
organic  substances  present  and  decomposes  any  lime  compounds  that  may 
have  been  in  the  madder.  The  whole  mixture  is  now  thrown  into  water, 
the  precipitate  collected,  washed,  and  dried.  The  guarancine  now  contains 
the  alizarin  and  Jmrpurin  in  uncombined  form.  The  yield  is  from  thirty- 
four  to  thirty-seven  per  cent.  For  the  preparation  of  "  madder  flowers" 
the  powdered  madder  is  set  to  ferment  with  warm  water  to  which  a  little 
dilute  sulphuric  acid  had  been  added.  After  some  days,  the  liquid  is  filtered 
and  the  residue  washed,  pressed,  and  dried.  The  flowers  of  madder  can  be 
used  more  readily  than  crude  madder  in  dyeing  at  low  temperatures,  and 
give  finer  and  purer  violets. 

(b)  Preparation  of  Ammoniacal  Cochineal  and  Carmine. — Five  parts  of 
powdered  cochineal  are  mixed  with  fifteen  parts  of  ammonia-water,  and  the 
mixture  is  allowed  to  stand  in  a  warm  place  with  frequent  stirring  for  some 
four  weeks.  Some  two  parts  of  alumina  are  then  added,  and  the  mixture 
carefully  evaporated  in  a  porcelain  dish  until  the  odor  of  ammonia  has  dis- 
appeared. The  preparation  so  obtained,  known  as  ammoniacal  cochineal, 
yields  its  color  more  readily  than  cochineal  and  produces  brighter  shades  of 
color. 

Cochineal-carmine  is  a  brilliant  red  pigment  prepared  from  decoction  of 
cochineal  by  the  action  of  alum  under  certain  conditions.  The  details  of 
its  preparation  vary  and  are  kept  by  different  manufacturers  as  trade  secrets. 
The  following  process  has  been  published  :f  Five  hundred  grammes  of  finely- 
powdered  cochineal  are  boiled  for  one-quarter  of  an  hour  with  thirty  times 
the  weight  of  distilled  water,  thirty  grammes  of  acid  tartrate  of  potassium 
added,  boiled  for  ten  minutes  longer,  fifteen  grammes  of  alum  added  and 
boiled  for  two  minutes  longer.  The  clear  liquid  is  allowed  to  stand  in  shal- 

*  Textile  Colorist,  xiii.  p.  125.  f  Schiitzenberger,  Die  Farbstoffe,  ii.  p.  338. 


PROCESSES  OF  TREATMENT. 


455 


FIG.  121. 


low  glass  vessels,  when  the  carmine  separates  in  a  very  fine  state.  It  is 
washed  with  water  and  dried  in  the  shade.  Or,  by  another  process,*  one 
pound  of  cochineal  and  one-half  ounce  of  potassium  carbonate  are  boiled  with 
seven  gallons  of  water  for  fifteen  minutes.  The  heat  having  been  with- 
drawn, one  ounce  of  powdered  alum  is  added,  and  the  liquid  stirred  and 
allowed  to  settle.  The  clear  liquid  is  decanted,  one-half  ounce  of  isinglass 
added,  and  heat  applied  until  a  coagulum  forms,  when  the  liquid  is  briskly 
stirred  and  allowed  to  settle. 

(c)  Preparation  of  Flavine. — As  stated  before  (see  p.  445),  flavine  is  a 
preparation  containing  the  coloring  matter  of  the  quercitron  bark  in  purer 
and  more  concentrated  form.     The  method  for  its  preparation  is  not  gener- 
ally known,  although  it  is  found  to  contain  quercetin  as  well  as  quercitrin, 
and  frequently  the  former  in  larger  amount. 

A  procedure  that  has  been  published  f  is  the  following  :  Two  hundred 
and  fifty  kilos,  of  the  powdered  quercitron  are  boiled  for  fifteen  minutes 
with  fifteen  kilos,  of  crystallized  soda  and  two  hundred  kilos,  of  water,  there 
is  then  added  to  the  liquid  sixty-one  kilos,  of  sulphuric  acid  of  66°  B.,  and 
the  boiling  continued  for  three-quarters  of  an  hour  longer,  when  the  whole 
is  allowed  to  cool  and  settle,  the  liquid  poured  off,  and  the  separated  color 
drained  and  dried. 

(d)  Preparation  of  Indigo-carmine,  Soluble  Indigo,  etc. — It  was  stated 
in  an  earlier  section  (see  p. 

447)  that  indigo-blue  was  sol- 
uble in  strong  sulphuric  acid. 
The  solubility  depends,  how- 
ever, upon  the  chemical  ac- 
tion of  the  acid,  whereby  sul- 
phonic  acids  of  indigo  are 
formed.  Two  such  acids, 
indigo-monosulphoni  c  acid 
(sulpho-purpuric  acid),  C16H9 
(HSO3)N2O2,  and  indigo-di- 
sulphonic  acid  (sulphindigotic 
acid),  C16H8(HSO3)2N2O2,  are 
formed.  Of  these,  the  first  is 
insoluble  in  water  or  dilute 
acids,  while  the  second  is  sol- 
uble with  deep-blue  color. 
Both  are  formed  together  in 
practice  when  indigo  is  dis- 
solved in  strong  sulphuric 
acid,  although  if  not  more 
than  four  parts  of  sulphuric 
acid  to  one  of  indigo  be  used 
and  too  prolonged  heating  be 
avoided,  the  monosulphonic 
acid  will  be  formed  predomi- 
nantly, while  if  some  fifteen 
parts  of  ordinary  concentrated  sulphuric  acid  or  seven  parts  of  fuming 


*  Allen,  Commercial  Organic  Analysis,  2d  ed.,  iii.  p.  367. 
f  Gerb-  und  Farbstoffe-Extracte,  Mierzinski,  p.  208. 


456  NATURAL  DYE-COLORS. 

sulphuric  acid  be  taken  to  one  of  indigo  and  the  heating  be  continued,  the 
disulphonic  acid  will  be  the  sole  product.  After  treatment  with  the  acid 
the  dissolved  mass  of  indigo  is  allowed  to  cool  down  and  then  strained  to 
remove  any  lumps  that  may  have  escaped  grinding;  salt  is  thrown  in, 
which  precipitates  the  indigo-sulphonic  acids,  which  are  removed  by  filtra- 
tion through  felt.  For  finer  grades  of  "  indigo  extract"  the  precipitate  is 
redissolved  in  water  and  reprecipitated  with  salt  several  times,  each  pre- 
cipitation removing  a  greater  quantity  of  the  objectionable  green  coloring- 
matter.  Whatever  be  the  process  or  proportion  of  acid  used,  the  indigo 
must  be  very  finely  ground.  This  is  done  in  indigo-mills,  which  are  of 
various  forms,  known  as  "ball- mills,"  in  which  rotating  cannon-balls 
gradually  grind  the  color,  as  "  cylinder-mills,"  in  which  heavy  iron  rolls 
accomplish  the  same  work,  and  other  forms.  An  illustration  of  such  an 
indigo-mill  with  conical  rolls,  taken  from  a  form  in  current  use,  is  shown 
in  Fig.  121.  The  direct  use  for  dyeing  of  the  product  obtained  by  the 
action  of  sulphuric  acid  upon  indigo  is  no  longer  common.  The  prepara- 
tion and  sale  by  the  color  manufacturers  of  pure  preparations,  known  as 
Indigo  Extract,  Soluble  Indigo,  or  Indigo-carmine,  has  replaced  them.  The 
sodium  salt  of  the  monosulphonic  acid  constitutes  "  indigo-purple"  or  "  red 
indigo-carmine,"  the  sodium  salt  of  the  disulphonic  acid  the  true  "  indigo- 
carmine,"  which  comes  into  commerce  in  paste  form  under  that  name  or  as 
a  dry  powder  known  as  "  Indigotin." 

This  indigo-disulphonic  acid  fixes  itself  on  the  animal  fibre  like  other 
acid  dye-colors,  and  hence  "  indigo-carmine"  has  an  extended  use  in  wool- 
dyeing.  The  wool  is  generally  mordanted  with  alum  and  then  dyed  in  an 
acid  bath  containing  sulphuric  acid. 


m.  Products. 

1.  FROM  KED  DYESTUFFS. — (a)  Brazil-wood  Extracts  are  made  by 
the  diffusion  process,  three  varieties  coming  into  commerce, — a  liquid  ex- 
tract of  20°  B.,  a  liquid  one  of  30°  B.,  and  a  solid  one.  One  kilo,  of  the 
dry  extract  corresponds  on  the  average  to  twelve  kilos,  of  the  wood.  Bra- 
silin  is  also  manufactured  on  a  large  scale  almost  pure  by  Geigy,  of  Basle. 

This  brasilin  often  separates  in  the  form  of  a  crystalline  crust  on  the 
surface  of  the  commercial  extract  liquors.  These  crusts  contain  the  bra- 
silin mixed  with  the  lime  compound  of  the  same.  If  this  crude  product 
is  boiled  with  very  dilute  alcohol  with  the  addition  of  zinc  dust  and  hydro- 
chloric acid  and  the  solution  stood  aside  to  crystallize  a  very  pure  product 
is  obtained. 

Brasilin  is  relatively  easily  soluble  in  water,  alcohol,  and  ether.  In 
alkalies  it  is  soluble  with  carmine-red  color.  Zinc  dust  will  decolorize  the 
solution,  but  on  exposure  to  the  air  it  speedily  takes  up  the  red  color  again. 
Acetate  of  lead  precipitates  a  colorless  crystalline  compound  which  gradu- 
ally turns  red.  Brasilein  bears  the  same  relation  to  brasilin  that  hsematein 
bears  to  hsematoxylin,  and  can  be  prepared  by  the  oxidation  of  the  alkaline 
solution  of  brasilin  in  the  air. 

Brazil-wood  extracts  are  used  in  wool-  and  cotton-dyeing.  With 
alumina  mordants  they  produce  shades  resembling  the  alizarin  lakes,  but 
inferior  in  character.  On  wool  mordanted  with  bichromate  of  potash  they 
produce  a  fine  brown. 


PRODUCTS.  457 

The  insolubility  of  the  coloring  matters  in  sandal-wood  prevents  their 
being  used  in  the  form  of  extracts. 

(6)  Madder  Preparations. — We  have  already  referred  to  Quarantine 
and  Flowers  of  Madder.  Guaranceux  is  the  name  applied  to  the  impure  pur- 
purin  recovered  from  the  sediment  of  the  waste-liquors  in  madder-dyeing. 

Pincoffin  (Alizarine  commertiale)  is  a  preparation  from  guarancine,  in 
which  the  purpurin  has  been  decomposed  by  superheated  steam,  leaving  the 
alizarin  unchanged.  It  has  twenty-five  per  cent,  less  coloring  power  than 
the  guarancine,  but  gives  finer  violets  than  can  be  obtained  with  the  former. 

(c)  Safflower  Preparations. — These  are  practically  more  or  less  pure  prep- 
arations of  carthamin,  and  the  names  Safflower  Extract,  Safflower-carmine, 
Safflower-red,  and  Plate-red  refer  to  diiFerent  concentrations  of  the  cartha- 
min solution.     For  the  preparation  of  the  pure  safflower-red,  the  safflower- 
yellow  must  be  removed  by  washing  the  crushed  flowers  with  water  until 
this  runs  off  colorless.     The  residue  is  then  treated  with  water  and  fifteen 
per  cent,  of  its  weight  of  crystallized  soda  salt.     The  solution  is  strained 
from  the  residue,  filtered,  and  after  acidulating  with  acetic  or  citric  acid, 
cotton  yarn  is  immersed  in  it  to  take  up  the  color.     The  dyed  cotton  is 
stripped  of  the  color  by  a  five  per  cent,  soda  solution,  and  from  this  solu- 
tion the  color  is  again  precipitated  by  citric  acid.     It  is  now  drained,  and 
comes  into  commerce  as  a  paste  known  as  "  Saffiower  Extract."     The  color 
must  be  kept  in  sealed  flasks,  protected  from  the  light.     This  paste  dried 
upon  plates  at  a  gentle  heat  yields  the  so-called  "  plate-red."    It  then  forms 
a  red  powder  with  greenish  reflex,  almost  insoluble  in  water  and  ether,  but 
easily  soluble  in  alcohol.     It  is  also  soluble  in  alkalies  with  yellowish-red 
color.     The  "  safflower-carmine,"  on  the  other  hand,  is  prepared  from  the 
extract  paste  by  washing  the  insoluble  color  and  dissolving  it  in  alcohol, 
which  is  then  left  to  slowly  evaporate.     For  dyeing  purposes  the  safflower- 
carmine  is  dissolved  by  addition  of  soda,  and  the  bath  is  then  made  slightly 
acid  with  citric  acid ;  or  the  soda-extraction  liquors  from  the  flowers,  which 
have  been  washed  with  water,  may  be  used  directly,  acidifying  the  bath  as 
before.    Safflower-red  is  fixed  in  a  weak  acid  bath  both  upon  the  animal  fibre 
and  upon  the  unmordanted  cotton.    On  silk  it  produces  a  fine  rose-red  color. 

(d)  Orseille  Preparations. — These  come  into  commerce  both  as  paste  and 
liquor.     The  solid  matter  consists  essentially  of  the  impure  orcein  in  com- 
bination with  ammonia.    It  is  liable  to  be  adulterated  with  the  spent  weeds 
from  the  manufacture  of  the  orseille  liquor  or  with  other  vegetable  coloring 
matters.    It  is  also  at  times  adulterated  with  aniline  dyes,  such  as  magenta, 
acid   magenta,  and   methyl  violet.     Various  azo  dyes,  producing  colors 
ranging  from  crimson  to  claret-red,  are  now  sold  as  substitutes  for  the 
orseille  extract,  and,  being  cheaper,  are  used  to  adulterate  it.     These  are 
known  as  "  orchil  extract,"  "  orchil-red,"  "orselline,"  etc.     They  may  be 
detected  when  so  admixed  by  their  behavior  with  salt  solution  and  basic 
acetate  of  lead.     The  liquid  extract  is  usually  brought  to  25°  B.,  and  is 
frequently  adulterated  with  logwood  or  Brazil-wood  extract.    Orseille  Purple 
(French  Purple)  is  a  pure  orseille  dye,  obtained  by  extraction  of  the  lichens 
with  a  fifteen  per  cent,  ammonia  solution,  precipitation  with  hydrochloric 
or  sulphuric  acid,  and  redissolving  in  ammonia.     This  solution  is  then  left 
exposed  to  the  air  in  shallow  vessels  until  it  becomes  dark  purplish- violet. 
The  color  is  then  precipitated  by  addition  of  sulphuric  acid,  washed,  and 
dried.     Orseille  Carmine  is  a  similar  preparation,  in  which  the  ammoniacal 
solution,  after  exposure  to  the  air  until  it  becomes  cherry-red,  is  heated 


458 


NATURAL  DYE-COLORS. 


with  alum  or  calcium  chloride.  Cudbear,  or  Perseo,  as  before  stated,  is  a 
dry  powder  obtained  by  evaporation  of  the  extract,  or  prepared  direct  from 
the  lichens  by  the  action  of  ammonia  or  urine  and  then  evaporated  to  the 
condition  of  a  powder.  It  is  often  adulterated  with  common  salt  and  other 
mineral  matters,  and  is  liable  to  much  the  same  organic  impurities  or 
adulterants  as  orseille. 

(e)  Cochineal  Preparations. — Ammoniacal  cochineal  and  cochineal-car- 
mine have  already  been  referred  to.  Ammoniacal  Cochineal  is  distinguished 
from  carminic  acid  by  giving  a  purple  or  violet  precipitate  (instead  of  scarlet) 
with  oxymuriate  of  tin.  The  crimson,  purple,  and  mauve  colors  it  yields 
with  mordants  are  not  affected  by  acids  so  readily  as  those  produced  directly 
by  cochineal.  Ammoniacal  cochineal  is  used  in  admixture  with  ordinary 
cochineal  for  producing  the  bluer  shades  of  pink.  Cochineal-carmine  re- 
quires for  its  production  a  decoction  of  cochineal  itself  and  not  of  carminic 
acid,  the  nitrogenized  matters  being  essential  to  its  formation.  Liebermann,* 
who  has  investigated  carefully  the  nature  of  the  cochineal  coloring  matter, 
found  it  to  contain  3.7  per  cent,  of  nitrogen,  of  which  only  .25  per  cent, 
could  be  expelled  by  boiling  with  dilute  alkali,  the  remainder  existing  ap- 
parently as  proteids.  He  gives  the  following  as  the  composition  of  the 
commercial  sample  of  carmine  examined  by  him :  Water,  seventeen  per 
cent.  ;  nitrogenous  matter,  twenty  per  cent. ;  ash,  seven  per  cent. ;  coloring 
matter,  fifty-six  per  cent. ;  wax,  traces.  Liebermann  considers  cochineal- 
carmine  to  be  no  ordinary  compound  of  a  coloring  matter  with  alumina,  but 
as  ar:  alumina-albuminate  of  the  carmine  coloring  matter,  comparable  in 
some  respects  to  the  product  from  alizarin  and  alumina  with  "  Turkey-red 
oil."  Carmine  forms  red,  porous,  relatively  light  masses,  which  are  easily 
rubbed  up  to  a  fine  red  powder.  It  is  insoluble  in  water  and  alcohol,  but 
readily  soluble,  when  pure,  in  aqueous  ammonia.  Cochineal -carmine  is  liable 
to  adulteration  with  starch,  kaolin,  vermilion,  red-lead,  chrome-red,  etc. 
These  admixtures  may  be  detected  by  treating  the  sample  with  dilute 
ammonia,  in  which  a  pure  sample  should  be  completely  and  readily  soluble. 

M.  Dechan  f  has  published  a  series  of  analyses  of  commercial  carmine, 
which  are  here  given  : 


1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 

10. 

Moisture    

22.1 

16.1 

2.0 

22.3 

20.2 

23.5 

85 

10.0 

21.2 

13.0 

Soluble  in  f  Coloring  matter    . 
ether.      (  Alumina,  lime,  etc. 

46.1 
8.0 

69.2 
9.8 

34.1 
11.4 

65.7 
12.0 

608 
9.0 

69.5 
7.0 

26.1 
0.4 

72.0 
8.1 

18.4 
4.4 

67.5 
10.0 

Solublein(?r£anicmatter  •  • 

21.8 
20 

2.5 
24 

18.5 
340 

Trace 

9.8 
02 

Trace 

146 

8.0 
1  9 

52.4 
36 

9.5 
Trace. 

ether.     \  vermilion.  .  .  .  '. 

50.4 

Cochineal  is  not  used  in  cotton-dyeing.  In  dyeing  silk  it  has  also  been 
almost  entirely  superseded  by  aniline  reds,  and  in  wool-dyeing  the  azo 
colors  have  to  a  great  extent  replaced  it.  Two  distinct  shades  of  red  are 
obtained  with  cochineal,  according  to  the  mordant  used, — cochineal-crimson 
with  cream  of  tartar  and  alum,  and  cochineal-scarlet  with  stannous  chloride 
and  cream  of  tartar  or  oxalic  acid. 

2.  FROM  YELLOW  DYESTUFFS.— (a)  Old  Fustic  Extracts.— Both  a 
liquid  extract  of  about  20°  B.  and  a  solid  extract  have  been  prepared.  The 


*  Ber.  Chem.  Ges.,  xviii.  p.  1971.  -f  Pharm.  Journ.  [3],  xvi.  p.  611. 


PRODUCTS. 


459 


latter  forms  large  yellowish-brown  blocks  of  a  waxy  lustre,  which  dissolve 
in  water  with  yellow  color.  They  are  prepared  from  the  wood  by  diffusion. 
The  name  morin  has  been  given  to  a  commercial  product  obtained  by  boiling 
the  rasped  wood  with  a  two  per  cent,  soda  solution  and  evaporating  the 
solution  so  obtained  to  a  specific  gravity  of  1.041,  when  on  cooling  the 
morin  and  moritannic  acid  separate  out. 

(6)  Quercitron  Extracts,  etc. — Both  liquid  and  solid  extracts  are  used 
commercially.  The  former  of  20°  and  30°  B.  respectively,  and  the  latter 
as  a  dark-brown  mass  of  waxy  lustre.  The  extracts  contain,  as  a  rule,  mix- 
tures of  quercitrin  and  quercetin.  Flavine  has  already  been  referred  to. 
It  is  a  preparation  in  which  the  quercitrin  of  the  bark  has  been  extracted 
and  in  large  part  changed  by  subsequent  treatment  with  sulphuric  acid  into 
quercetin,  which  is  superior  in  coloring  power.  The  tannic  acid  of  the  bark 
extract  has  also  been  removed  and  the  lime  salts,  so  that  it  gives  much  purer 
colors  than  the  original  extract.  Flavine  is  largely  used  in  connection  with 
cochineal  or  lac-dye  for  producing  scarlet.  A  quercitron  extract  to  which 
stannite  of  soda  or  sulphate  of  zinc  has  been  added  is  said  to  be  used  under 
the  name  of  "  Fustic  Substitute."  It  can  be  told  from  genuine  extract  of 
fustic  by  the  test  with  ferric  chloride,  which  produces  a  brown  precipitate, 
turning  olive-green  with  fustic,  but  a  greenish-black  with  quercitron  extract. 

(c)  Persian  Berries. — A  thick  extract  is  prepared  from  Persian  berries, 
soluble  in  water  with  yellow  color  shading  into  brown.  The  solution  be- 
comes clearer  on  addition  of  hydrochloric  or  nitric  acids  and  deposits  a 
dirty  yellow  precipitate.  Ammonia  or  caustic  soda  color  it  a  reddish-yellow, 
stannous  chloride  gives  at  once,  and  stannic  chloride  after  the  addition  of 
carbonate  of  soda,  a  golden-yellow  precipitate,  iron  salts  a  dark  olive-green 
to  greenish-black  color. 

3.  FROM  BLUE  DYESTUFFS. — (a)  Commercial  Indigo  occurs  in  lumps 
or  fragments  of  a  deep-blue  color,  usually  showing  a  bronze  or  purple-red 
streak  when  rubbed  with  any  hard  substance,  or  in  the  case  of  the  better 
kinds  with  the  friction  of  the  thumb  only.  The  fracture  of  indigo  is  dull 
and  earthy,  it  sticks  to  the  tongue,  is  odorless  and  tasteless.  The  specific 
gravity  varies  from  1.324  to  1.455.  Helen  Cooley  *  has  given  the  follow- 
ing determinations  of  indigotin,  ash,  and  specific  gravity  in  a  number  of 
samples  of  commercial  indigo  : 


DESCRIPTION. 

Specific  gravity. 

Ash. 

Indigotin. 

Kurpah  blue    

1.129 

17.54 

55.11 

Watson's  be^t 

1  292 

6  50 

59  53 

Bengal  red 

1  391 

6  41 

54  03 

Qude  

1  427 

7  02 

52  90 

1  431 

7  50 

57  60 

Kurpah  red  

1.529 

21  20 

4528 

Guatemala 

1  559 

14  49 

47  04 

Indigo  preparations  have  been  referred  to  under  processes  (see  p.  455), 
and  it  was  then  noted  that  the  salts  of  the  indigo-sulphonic  acids  constituted 
the  several  so-called  indigo  extracts.  Indigo-carmine  is  the  potassium  or 
sodium  sulphindigotate  (C16H8(SO3K)2N2O2).  It  conies  into  commerce  in 

*  Amer.  Journ.  Anal.  Chem.,  ii.  p.  130. 


460  NATURAL  DYE-COLORS. 

both  paste  and  solid  form.  It  is  soluble  in  one  hundred  and  forty  parts  of 
cold  water,  readily  soluble  in  dilute  sulphuric  acid.  It  dyes  animal  fibres 
direct,  but  with  a  much  lighter  shade  than  indigo,  and  is  not  at  all  so  fast 
to  light,  while  to  vegetable  fibres  it  shows  no  affinity.  An  analysis  of  the 
several  grades  of  carmine-paste  by  Mierzinski  *  gave  : 


DESCRIPTION. 

Water. 

Indigo. 

Salt. 

Carmine  I  

89.0 

4  96 

5  7 

Carmine  II  

850 

10  02 

4  8 

Carmine  III  

73  7 

1204 

13  9 

Saxony  Blue  (Chemic  Blue)  is  the  free  sulphindigotic  acid,  C16H8N2O2 
(SO3H)2,  and  forms  a  deep-blue  solution.  It  is  prepared  as  in  the  making 
of  indigo-carmine,  except  the  acid  is  not  saturated  with  alkali.  It  was 
largely  used  in  dyeing  wool,  but  is  not  adapted  for  silk.  Indigo-purple  is 
a  reddish-violet  powder,  which  mixed  with  varying  amounts  of  orseille  can 
be  used  for  dyeing  wool  directly  without  mordants.  For  its  preparation, 
powdered  indigo  is  covered  with  ordinary  (not  fuming)  sulphuric  acid,  and 
having  been  cooled  is  left  for  half  an  hour.  In  this  way  is  obtained  a  blue 
solution  of  sulphindigotic  (indigo-disulphonic)  acid,  which  can  be  worked 
up  into  indigo-carmine  and  a  violet  powder.  This  latter  is  the  monosul- 
phonic  acid,  which  is  washed  first  with  water  and  then  with  dilute  soda 
solution  until  the  washings  are  no  longer  acid,  then  dried  for  use  as  above. 
A  product  of  analogous  composition,  known  as  Boiley's  Blue,  is  prepared  by 
gradually  adding  one  part  of  finely-powdered  indigo  to  ten  or  twenty  parts 
of  acid  sodium  sulphate,  HNaSO4,  in  a  state  of  fusion.  The  product  is 
dissolved  in  water,  precipitated  with  common  salt,  and  washed  with  brine. 
Boiley's  blue  is  a  crystalline  light-purplish  mass,  soluble  in  water  with 
beautiful  blue-violet  color.  Its  solution  in  strong  boiling  acetic  acid 
deposits  on  cooling  large  prismatic  crystals  exhibiting  a  coppery  reflection. 
It  is  insoluble  in  alcohol  or  ether,  but  readily  soluble  in  hot  water.  The 
light  transmitted  by  the  solution  is  red.  With  barium  and  strontium  salts  it 
yields  violet  precipitates. 

The  fact  that  indigo  had  been  obtained  artificially  by  several  different 
methods  was  mentioned  under  the  artificial  dye-colors.  (See  p.  420.)  A 
synthesis  of  indigo-carmine  has  also  been  effected  within  recent  years. 
The  process,  due  to  B.  Heymann,t  is  as  follows  :  One  part  of  phenyl-glyco- 
coll  (C6H6.NHCH2.COOH)  is  rubbed  up  with  ten  to  twenty  times  its  volume 
of  clean  sand  (which  simply  acts  in  the  way  of  reducing  the  temperature  of 
the  reaction),  and  slowly  added  to  fuming  sulphuric  acid,  with  eighty  per 
cent,  anhydride  strength,  warmed  to  20°  or  25°  C.  Care  is  to  be  taken  that 
the  temperature  does  not  thereby  exceed  30°  C.  After  the  solution  of  the 
phenyl-glycocoll,  which  takes  place  with  evolution  of  sulphurous  oxide, 
concentrated  sulphuric  acid  of  66°  B.  is  added  to  remove  the  excess  of 
anhydride.  It  is  then  diluted  with  ice  and  common  salt  added,  when  indigo- 
carmine  (indigo-disulphonic  acid)  at  once  separates  out.  Experiments  on 
dyeing  with  the  new  product  show  it  to  be  better  and  purer  than  the  com- 
mercial indigo-carmine.  Its  identity  was  established  in  a  number  of  ways. 

*  Ganswindt,  Farberei,  p.  150.  f  Ber.  Chem.  Ges.,  xxiv.  p.  1476. 


PRODUCTS. 


461 


The  yield  at  present  amounts  to  sixty  per  cent,  of  the  theoretical,  but  this 
may  be  improved  by  further  study  of  the  conditions  of  the  reaction. 

(6)  From  Logwood. — Logwood  Extracts  are  prepared  as  liquids  of  12°, 
42°,  and  51°  Tw.  (for  equivalents  of  the  Beaum6  scale,  see  Appendix)  and 
as  a  solid.  This  latter  forms  a  dry  black,  lustrous  and  resin-like  mass, 
which  is  quite  brittle  and  easily  powdered,  tastes  sweetish  astringent,  and 
yields  a  reddish-brown  solution.  The  specific  gravity  ranges  from  1.45  to 
1.51.  The  specific  gravity  is  not  a  reliable  indication  of  the  strength  of 
the  fluid  extract,  as  it  is  liable  to  be  raised  by  the  addition  of  salt,  glucose, 
molasses,  etc.  The  extracts  are  also  sometimes  adulterated  with  starch, 
dextrin,  chestnut-bark  extract,  hemlock  extract,  etc.  The  following  table 
by  Briihl  *  gives  the  yields  of  extracts  obtained  by  himself  from  different 
woods  and  the  percentage  solubility  of  the  resulting  extracts  in  ether  and 
alcohol.  The  portion  dissolved  by  ether  represents  roughly  the  hsematoxy- 
lin  percentage,  while  that  dissolved  by  absolute  alcohol  represents  the 
haematein  and  decomposition  products  of  the  hsematoxylin. 


DESCRIPTION  OF  WOOD. 

Yield  of 
extract 

Soluble  in 
ether. 

Soluble  iu 
absolute 
alcohol. 

Residue. 

Yucatan 

20.20 
17.34 
21.00 
14.02 
19.30 
18.75 
14.00 
20.33 
16.00 
17.45 
18.00 
1870 
18.00 
10.70 

60.12 
58.34 
51.37 
44.95 
43.81 
32.00 
34.72 
41.89 
50.00 
59.72 
59.24 
43.20 
43.05 
52.99 

37.46 
38.51 
47.95 
53.47 
50.32 
60.32 
54.10 
54.11 
47.92 
35.17 
34.81 
50.50 
50.71 
3012 

2.42 
3.15 

0.68 
1.58 
5.87 
7.68 
11.18 
4.00 
2.08 
5.21 
5.95 
6.30 
6.24 
16.89 

Yucatan  E   J 

Lasruna 

St   Domingo 

St.  Dominsjo,  O             .            . 

Monte  Christo,  1884            

Monte  Christo,  1887         .    .            ... 

Fort  Liberte,  1886            

Fort  Liberte,  1887    

Fort  Liberte,  1885-86  

Fort  Liberte,  J.  B.,  1887    

Jamaica 

Jamaica 

Jamaica  wood  roots 

Indigo  Substitute  (Noir  imperial,  or  Kaiser  schwarz). — Under  these  names 
are  known  oxidized  logwood  extracts,  made  by  boiling  logwood  extract  with 
copper,  iron,  or  chromium  salts  with  the  addition  of  oxalic  acid.  They 
may  be  in  liquid  form,  or  pastes,  or  dry  powders.  The  preparations  are 
almost  insoluble  in  water,  but  completely  soluble  in  acids  with  yellowish- 
brown  color.  A  commercial  preparation  of  this  class,  known  as  "  direct 
black,"  for  cotton  forms  a  brownish,  viscid  liquid,  composed  of  fifty  per 
cent,  water,  forty-five  per  cent,  of  a  substance  soluble  in  alcohol  and  ether 
(hsematoxylin  and  hsematein),  and  3.5  per  cent,  of  copper  sulphate.  Hcem- 
atein  (Hematin)  is  a  commercial  preparation  of  French  origin,  which  claims 
to  consist  of  nearly  pure  dyestuff.  It  forms  a  granular,  reddish-brown 
powder,  completely  soluble  in  water,  and  dyes  the  same  shades  as  those  ob- 
tained from  the  wood.  Fifteen  kilos,  of  hsematein  are  said  to  be  equiva- 
lent to  one  hundred  kilos,  of  the  logwood. 

(c)  Litmus,  as  has  been  said,  is  a  mixture  of  the  lichen  dye  of  that 
name  with  chalk  or  gypsum  as  inert  material.  It  is  made  in  different 
numbered  grades,  containing  different  amounts  of  the  mineral  matter.  Lit- 


Textile  Colorist,  x.  p.  148. 


462  NATURAL  DYE-COLOKS. 

mus  in  the  dry  form  has  a  violet-blue  color,  is  quite  friable,  and  dissolves 
in  water  and  dilute  alcohol,  leaving  a  residue  of  chalk,  gypsum,  alumina, 
silica,  etc. 

4.  FROM  BROWN  DYES. — (a)  Catechu  has  been  described  already  in  part 
under  the  raw  materials  of  the  tanning  industry.  (See  p.  322.)  It  is  not 
unfrequently  adulterated  with  starch,  sand,  clay,  and  blood.  Good  catechu 
should  yield  at  least  half  its  weight  to  ether  and  should  be  entirely  soluble 
in  boiling  water,  the  latter  solution  depositing  catechu  on  cooling.  Catechu 
does  not  wholly  dissolve  in  cold  water  unless  it  has  been  previously  modi- 
fied by  age  or  exposure  to  damp.  It  should  not  yield  more  than  five  per  cent, 
of  ash.  Prepared  Catechu  has  been  merely  purified  by  mechanical  means. 
For  this  purpose,  the  commercial  catechu  is  fused  on  the  water-bath, 
whereby  sand,  earth,  and  similar  impurities  settle  out,  and  then  it  is  strained 
to  remove  leaves,  etc.  The  material  so  obtained  is  again  melted  on  the 
water-bath,  and  to  every  one  hundred  parts  of  the  catechu  three-fourths  per 
cent,  of  potassium  bichromate  is  added,  when  it  is  allowed  to  cool  down 
again. 

IV.  Analytical  Tests  and  Methods. 

1.  FOR  DYE-WOODS. — Here  the  question  of  adulteration  does  not  come 
notably  in  play.     The  compact  woods  are  not  capable  of  much  adulteration 
of  any  kind.     When  chipped  or  rasped,  however,  they  may  be  adulterated 
quite  considerably.     The  examination  with  the  microscope  or  simple  lens 
will  often  suffice  to  indicate  the  nature  of  this  adulteration.     A  special  case 
of  cheapening  is  that  of  the  cured  or  fermented  logwood  chips,  which,  as 
has  already  been  stated,  may  take  up  as  the  result  of  this  fermentative  pro- 
cess as  much  as  thirty  to  forty  per  cent,  of  water.     In  this  case  a  moisture 
determination  will  show  the  change,  allowance  being  made  for  the  fourteen 
per  cent.,  which  is  the  average  moisture  of  the  unfermented  wood. 

To  determine  the  comparative  dyeing  value  of  different  samples  of 
woods,  the  only  thoroughly  reliable  test  is  an  actual  dyeing  test  made  with 
definite  weights  of  the  wood,  thoroughly  extracted,  and  using  definite 
amounts  of  mordants  upon  the  wool  or  other  fibre  used.  This  test,  as 
applied  to  logwood,  for  example,  would  be  carried  out  as  follows  :  *  "  Some 
white  wool  is  boiled  in  a  solution  of  potassium  bichromate  containing  such 
an  amount  of  the  salt  as  will  correspond  to  three  per  cent,  of  the  weight  of 
the  wool.  The  mordanted  wool  is  then  introduced  in  small  successive  por- 
tions into  the  hot  liquid  to  be  tested  (logwood  decoction  or  extract),  when 
it  will  be  dyed  black,  and  the  weight  which  can  be  thus  dyed  will  be  an 
indication  of  the  amount  of  the  coloring  matter.  This  method  of  logwood 
assay  takes  cognizance  both  of  the  actual  and  the  potential  coloring  matter 
present  (hsematein  and  hsematoxylin),  and  is  a  more  rational  method  of 
examination  than  any  based  on  the  color  produced  on  cotton  mordanted 
with  alumina  or  tin  salts."  The  dye  test  in  other  cases  must  be  made  upon 
a  normal  prepared  extract  of  known  strength  and  purity,  and  the  result 
compared  with  those  obtained  with  a  corresponding  weight  of  the  supposed, 
adulterated  sample. 

2.  FOR  DYE-WOOD  AND  OTHER  EXTRACTS. — (a)  Or  settle  Extract. — This 
may  be  adulterated  with  logwood  or  Brazil-wood  extract.     They  may  be  de- 
tected, according  to  Leeshing,  as  follows  :  A  solution  of  orseille  extract,  much 

*  Allen,  Commercial  Organic  Analysis,  2d  ed.,  iii.  p.  330. 


ANALYTICAL   TESTS   AND   METHODS. 


463 


diluted  and  acidified  with  acetic  acid,  will,  if  pure,  when  boiled  with  a 
freshly  prepared  solution  of  stannous  chloride,  become  pale  yellow  or  almost 
colorless,  while  logwood  extract  solution  under  similar  circumstances  will 
show  a  violet  color  and  Brazil-wood  solution  a  red  color.  If,  therefore,  the 
orseille  is  adulterated  with  logwood  extract  a  permanent  grayish-blue  color 
will  show,  if  with  Brazil-wood  extract,  a  reddish  color. 

Orseille  is  also  found  frequently  to  have  been  adulterated  with  aniline 
dyes,  especially  magenta,  acid  magenta,  and  methyl  violet.  For  the  detec- 
tion of  magenta  and  methyl  violet  Knecht  *  employs  cotton  yarn  dyed  with 
chrysamin  (p.  419).  This  does  not  take  up  the  coloring  matter  of  the 
orseille,  but  is  dyed  red  by  magenta  and  brownish-red  by  methyl  violet. 
To  detect  the  acid  magenta,  Kertesz  f  treats  the  orseille  preparation  with 
benzaldehyde  and  adds  to  the  solution  tin  salt  and  hydrochloric  acid, 
shaking  up  the  mixture  thoroughly.  If  acid  magenta  was  present  a  red 
color  will  remain,  while  with  pure  orseille  the  solution  remains  colorless. 
One  part  of  acid  magenta  in  one  thousand  parts  of  orseille  it  is  said  can  be 
thus  detected.  For  other  tests  for  the  artificial  dye-colors  when  present  as 
adulterants  in  orseille,  see  Allen,  "  Commercial  Organic  Analysis,"  2d  ed., 
iii.  pp.  322  and  323. 

(b)  Quercitron  Extracts. — The  dyeing  value  of  the  extract,  as  well  as  a 
possible  adulteration  of  the  same  with  dextrin,  glue,  etc.,  can  be  best  de- 
termined by  an  actual  dye  test.     For  this  purpose,  wool  is  boiled  with  1.5 
per  cent,  of  tin  salt  and  three  per  cent,  of  oxalic  acid,  then  washed.     One 
gramme  of  the  wool  is  now  dyed  with  twenty  cubic  centimetres  of  a  solu- 
tion of  ten  grammes  of  the  quercitron  extract  in  one  thousand  cubic. centi- 
metres of  water.     Similarly  several   portions  of  one  gramme  each  of  mor- 
danted wool  are  dyed  with  solutions  of  pure  bark  or  pure  extract  of  definite 
strength,  and  the  results  compared. 

(c)  Annatto  (Orleari). — Annatto  possesses  only  a  slight  importance  as  a 
dyeing  agent,  but  special  importance  as  the  basis  of  most  butter  colorings. 
(See  p.  270.)     It  is  therefore  a  commercial  article  of  common  use  and  liable 
to  be  adulterated.     The  common  adulterants  are   starch,  dextrin,  chalk, 
silica,  alumina  compounds,  and  common  salt,  together  with  ochre,  brick- 
dust.     Most  of  these  increase  notably  the   percentage  of  ash,  which  in  a 
pure  sample  it  is  said  should  not  exceed  ten  to  twelve  per  cent.     Wynter 
Blyth  gives  the  following  two  analyses  as  illustrating  the  nature  of  its 
adulteration : 


DESCRIPTION. 

Water. 

Resin. 

Extractive 
matter. 

Ash. 

Fair  commercial  sample    .    . 
Adulterated  sample    .... 

242 
13.4 

28.8 
11.0 

245 
27.3 

22.5 

40  Q  1  Oxide  of  iron,  alumina, 
'    J    silica,  chalk,  and  salt. 

For  dyeing  purposes  the  only  satisfactory  test  is  an  actual  dyeing  test  in 
comparison  with  an  authentic  unadulterated  sample.  For  the  analysis  of 
the  many  butter-coloring  mixtures  containing  annatto  as  the  basis  the  reader 
is  referred  to  Allen,  "Commercial  Organic  Analysis/7  2d  ed.,  iii.  pp.  353-356, 
and  Wynter  Blyth,  "  Foods,  Composition  and  Analysis,"  p.  306. 


*  Journ.  Soc.  Dyers,  etc.,  ii.  p.  58. 


f  Dingier,  Polyt.  Journ.,  256,  p.  281. 


464 


NATURAL  DYE-COLORS. 


(d)  Logwood  Extract. — Both  the  liquid  and  the  solid  extracts  are  liable 
to  be  adulterated,  the  former  with  glucose,  molasses,  dextrin,  salt,  and 
other  extracts  of  lesser  value,  the  latter  with  starch  and  inferior  extracts. 
Notably  are  the  French  and  German  logwood  extracts  adulterated  in  the 
way  just  referred  to.  The  following  analyses  of  some  of  the  commercial 
extracts  as  currently  sold  in  France  and  Germany  are  given  by  V.  H. 
Soxhlet  :* 


DESCRIPTION  OF  EXTRACT. 

Molasses. 

Dextrin. 

Chestnut  extract. 

Salt. 

Guaranteed  Pure,  30°  B.  .    . 
Prima  30°  B 

5  per  cent. 
10 

Secunda   30°  B 

20 

10  per  cent. 

10  per  cent. 

Secunda  Solid            .    . 

20 

15   "       " 

Sanford  Brand,  I  

25 

15  per  cent. 

Sanford  Brand,  II  
Sanford  Brand,  III  

35 

35 

10   »       " 
15   "       " 

10   "       " 
15   "       " 

The  Sanford  Brand  here  referred  to  is  a  French  extract  made  in  imita- 
tion of  the  original  American  Sanford  Extract. 

The  extracts  may  be  tested  for  purity  either  by  the  colorimetric  assay 
or  by  comparative  dye  tests.  The  colorimetric  test  is  carried  out,  according 
to  Henry  Trimble,f  as  follows :  A  volume  of  solution  corresponding  to 
.001  gramme  of  the  dry  extract  is  treated  with  ten  cubic  centimetres  of 
water  naturally  or  artificially  containing  traces  of  calcium  carbonate  and  a 
solution  of  .002  gramme  of  crystallized  copper  sulphate.  The  mixture  is 
brought  quickly  to  the  boiling-point  and  diluted  with  distilled  water  to  one 
hundred  cubic  centimetres.  The  color  of  this  solution  is  then  compared 
with  one  of  pure  hsematoxylin  similarly  treated,  or  with  a  standard  sample 
of  logwood  extract. 

The  method  of  carrying  out  the  dye  test  for  logwood  with  bichromate 
of  potassium  mordant  has  already  been  given  in  speaking  of  dye-woods. 
The  same  test  is,  of  course,  equally  applicable  to  the  extracts.  Cotton 
strips  are  sometimes  used  for  these  dye  tests  instead  of  wool.  The  cotton 
strips  must  be  boiled  in  dilute  soda  solution  and  well  washed.  They  may 
then  be  mordanted  with  nitrate  of  iron  solution  instead  of  the  chromium  salt, 
following  the  nitrate  of  iron  with  a  rinsing  in  carbonate  of  soda  solution  and 
thorough  washing.  They  are  then  put  in  the  dye-bath  cold,  and  this 
gradually  heated  to  boiling.  In  this  dye-testing  with  iron  solution,  the 
hsematoxylin  of  the  solution  is  oxidized  by  the  ferric  oxide  to  hsematein,  so 
that  the  full  coloring  value  of  the  logwood  is  obtained  in  the  test. 

For  the  discovery  of  adulterations  like  chestnut  extract,  which  con- 
tain almost  nothing  soluble  in  ether,  Houzeau  proceeds  as  follows :  One 
gramme  of  the  extract  to  be  investigated  is  dried  at  110°  C.,  exhausted 
with  ether,  and  the  weight  of  the  dissolved  material  determined.  The  un- 
dissolved  material  is  then  exhausted  with  absolute  alcohol,  and  the  weight 
of  the  portion  dissolved  by  this  also  determined.  The  comparison  of  the 
figures  so  obtained  with  those  yielded  when  a  pure  extract  is  treated  with 
the  same  solvents  will  show  clearly  the  presence  or  absence  of  adulterating 
extract.  Dye  tests  may  also  be  carried  out  with  the  material  which  has 


*  Farber-Zeitung,  Aug.  1,  1890,  p.  368. 


f  Journ.  Soc.  Dyers,  etc.,  i.  p.  92. 


ANALYTICAL  TESTS  AND  METHODS.  465 

been  extracted  by  ether  and  alcohol  respectively  in  the  two  cases,  and  the 
difference  more  fully  established. 

(e)  Catechu  Extract. — Catechu  is  frequently  adulterated,  not  only  with 
mineral  matter  like  sand  and  clay,  but  with  starch,  dextrin,  sugar,  blood, 
etc.  The  mineral  matters  will,  of  course,  remain  in  the  ash.  This  in 
normal  catechu  should  not  exceed  five  per  cent.  The  starch  may  be  de- 
tected by  extracting  the  sample  with  alcohol,  boiling  the  insoluble  residue 
with  water,  and  testing  the  cooled  liquid  with  iodine,  which  will  show  by 
the  blue  color  any  starch  present.  An  addition  of  alcohol  to  the  aqueous 
solution  will  show  by  the  production  of  a  turbidity  any  notable  quantity  of 
dextrin.  Blood  may  be  detected  by  treating  the  sample  with  alcohol,  and 
drying  and  heating  the  residue  in  a  tube,  when  ammonia  and  offensive  de- 
composition products  will  be  given  off,  or  the  coagulation  of  the  blood 
albumen  when  the  aqueous  solution  is  boiled. 

The  value  of  catechu  for  dyeing  purposes  can  only  be  determined  by  a 
dye  test.  For  this  purpose  strips  of  cotton-stuff  are  immersed  for  half  an 
hour  in  a  catechu  solution  (for  each  gramme  of  the  cotton  fifty  cubic  centi- 
metres of  a  catechu  solution  containing  five  grammes  to  the  litre  of  water 
are  taken  and  diluted  with  water  if  necessary).  The  strips  are  pressed  out, 
and  then  the  color  developed  by  oxidizing  in  a  hot  solution  of  one  to  two 
grammes  of  potassium  bichromate  to  the  litre  of  water. 

3.  FOR  COCHINEAL. — The  adulteration  of  cochineal  may  be  effected  in 
various  ways.  A  very  common  adulteration  is  to  admix  with  the  fresh 
cochineal  insects  others  from  which  the  coloring  power  has  already  been  in 
large  part  extracted.  To  give  the  exhausted  cochineal  insects  the  appear- 
ance of  fresh  ones,  they  are  shaken  up  with  talc,  barytes,  and  white  lead, 
and  thus  given  a  coating  resembling  the  silvery  insects.  Either  a  wash- 
ing or  an  ash  determination  will  serve  to  detect  this  adulteration  The 
valuation  of  the  cochineal  as  to  coloring  power  may  be  made  by  several 
methods.  The  one  best  known  is  that  of  Penny,*  in  which  one  gramme  of 
the  cochineal  is  treated  with  fifty  grammes  of  dilute  potassium  hydrate, 
twenty-five  grammes  of  water  added,  and  to  this  is  then  added  drop  by 
drop  a  solution  of  ferricyanide  of  potassium  containing  five  grammes  to 
the  litre.  The  solution  loses  its  purplish-red  color  and  becomes  brownish- 
yellow.  The  action  of  the  ferricyanide  of  potassium  solution  is  tested  in 
comparison  on  the  solution  of  one  gramme  of  a  cochineal  of  known  purity. 
Liebermann  f  extracts  the  cochineal  with  boiling  water,  and  determines  the 
coloring  matter  by  the  addition  of  a  slightly  acid  solution  of  lead  acetate. 
After  filtering  and  washing  the  lead  precipitate,  a  lead  determination  is 
made  in  an  aliquot  portion,  and  from  this  the  percentage  of  coloring  matter 
calculated.  Allen  does  not  consider  either  of  these  methods  to  be  perfectly 
satisfactory.  An  actual  dye  test  is  therefore  in  the  end  to  be  regarded  as 
the  most  reliable  method  of  valuation.  For  this  purpose  strips  of  woollen 
stuff  of  about  five  grammes  in  weight  are  put  into  the  bath  until  the  color 
is  all  taken  up.  A  portion  of  the  strips  may  then  be  dyed  scarlet-red  by 
immersing  them  in  a  tin  solution  (for  one  gramme  of  cochineal  two  grammes 
of  cream  of  tartar,  two  grammes  of  tin  salt,  and  as  much  water  as  is  needed 
to  thoroughly  immerse  the  strips),  and  the  other  portion  of  the  strips  may 
be  dyed  a  cherry-red  by  the  use  of  an  alum  solution  (for  one  gramme  of 
cochineal,  three-fourths  gramme  of  cream  of  tartar  and  one  and  a  half 

*  Journ.  fur  Prakt.  Chem.,  71,  p.  119.      |  Berichte  der  Chem.  Ges.,  xviii.  p.  1970. 

30 


466  NATURAL  DYE-COLORS. 

grammes  of  alum).  These  strips  are  then  to  be  compared  with  others  ob- 
tained from  similar  treatment  of  a  normal  or  pure  cochineal  sample. 

4.  FOR  INDIGO  AND  ITS  PREPARATIONS. — Indigo  may  be  of  very 
varying  value  as  it  comes  into  commerce,  partly  because  of  the  differences 
natural -to  such  a  product  and  dependent  upon  the  differences  in  cultivation 
of  the  plant,  care  in  extracting  and  drying  the  indigo,  and  the  fact  that  the 
natural  product  is  at  best  a  mixture,  and  partly  from  intentional  adultera- 
tion. Thus  starch  colored  with  iodine,  Prussian  blue,  smalt,  and  logwood- 
powder  are  said  to  be  used  as  adulterants  of  commercial  indigo.  In  order 
to  detect  the  starch,  the  suspected  sample  is  rubbed  up  in  a  mortar  with 
chlorine-water  until  it  is  completely  decolorized,  when  a  drop  of  potassium 
iodide  is  added.  If  starch  be  present  the  blue  color  of  iodide  of  starch 
will  be  seen.  To  detect  the  smalt  or  Prussian  blue,  the  sample  is  oxidized 
with  nitric  acid,  when  if  a  blue  residue  is  shown  in  the  yellowish  solution 
adulteration  is  indicated.  If  the  adulterant  were  Prussian  blue,  the  color 
fades  too  after  a  time,  if  smalt,  it  is  permanent.  To  detect  logwood-powder, 
mix  the  sample  with  oxalic  acid,  place  it  upon  filter- paper,  and  moisten  it ; 
in  the  presence  of  logwood  the  paper  will  be  colored  red,  if  the  sample  were 
pure  it  is  unchanged. 

In  the  assay  of  commercial  indigo  the  moisture  is  generally  to  be  deter- 
mined. This  should  not  exceed  some  seven  per  cent,  in  a  genuine  sample. 
The  ash  similarly  is  an  important  criterion  of  the  quality  of  the  indigo 
sample.  In  the  purest  kinds  it  is  sometimes  as  low  as  two  per  cent.,  but 
from  five  to  eight  per  cent,  is  more  usual.  Some  of  the  inferior  grades  of 
indigo,  such  as  Kurpah  and  Madras,  may  contain  from  twenty-five  to  thirty- 
five  per  cent,  of  ash. 

The  methods  for  the  determination  of  the  percentage  of  indigo-blue  are, 
of  course,  the  most  important  things  to  be  considered  in  connection  with 
indigo  as  a  dyeing  material.  They  are  very  numerous.  We  may  sum- 
marize the  more  important  of  them  under  three  heads, — viz.,  oxidation 
methods,  reduction  methods,  and  sublimation  of  the  pure  indigo-blue  from 
the  commercial  product. 

The  oxidation  of  the  indigo-blue  takes  place  in  acid  solution,  the  indigo 
being  previously  dissolved  in  strong  sulphuric  acid.  Potassium  perman- 
ganate, bichromate,  and  ferricyanide  have  all  been  recommended  and  used 
in  this  connection.  All  the  processes  are  open  to  the  objection  that  the 
oxidizing  agents  act  on  the  indigo-gluten  and  ferrous  salts  as  well  as  on  the 
indigo-blue  and  indigo-red,  but  the  errors  due  to  this  cause  may  be  practi- 
cally avoided,  as  pointed  out  by  Rawson,  by  previously  precipitating  the 
sulphindigotic  acid  in  the  form  of  the  sodium  salt  by  adding  common  salt  to 
the  solution.  The  method  with  permanganate  of  potassium,  modified  in 
this  manner  by  the  use  of  common  salt,  is  as  follows  :*  One  gramme  of  the 
sample  of  indigo  in  the  form  of  an  impalpable  powder  is  mixed  in  a  small 
mortar  with  its  own  weight  of  ground  glass.  This  mixture  is  gradually 
added  with  constant  stirring  to  twenty  cubic  centimetres  of  concentrated  sul- 
phuric acid  (specific  gravity  1.845),  which  is  then  heated  to  about  85°  C. 
for  an  hour.  The  product  is  then  cooled,  diluted  with  water  to  one  litre, 
and  filtered  from  indigo-brown  and  other  soluble  matter.  Fifty  cubic 
centimetres  of  the  filtered  solution  are  now  taken  diluted  with  fifty  cubic 
centimetres  of  water,  and  thirty-two  grammes  of  common  salt  added,  which 

*  Allen,  Commercial  Organic  Analysis,  2d  ed.,  iii.  p.  308. 


ANALYTICAL  TESTS  AND  METHODS.  467 

quantity  is  almost  sufficient  to  saturate  the  liquid.  After  standing  for  two 
hours,  the  solution  is  filtered,  and  the  precipitate  washed  with  about  fifty 
cubic  centimetres  of  brine  of  1.2  specific  gravity.  This  sodium  sulphindi- 
gotate  is  dissolved  in  hot  water,  the  solution  cooled,  mixed  with  one  cubic 
centimetre  of  sulphuric  acid,  and  diluted  to  three  hundred  cubic  centimetres. 
This  solution  is  then  titrated  in  a  porcelain  dish  with  a  solution  of  potas- 
sium permanganate  containing  .5  gramme  of  the  solid  salt  per  litre,  the 
exact  oxidizing  power  of  which  has  been  ascertained  by  experiment  with 
a  solution  of  pure  indigotin.  The  oxidation  is  regarded  as  complete  when 
the  liquid  which  at  first  takes  a  greenish  tinge  changes  to  a  light  yellow 
with  a  faint  pink  color  on  the  margin. 

The  reduction  of  indigo-blue  may  take  place  in  alkaline  solution  or 
with  a  solution  of  the  sulphindigotic  acid  or  its  salts.  Ferrous  hydroxide 
and  hyposulphites  are  among  the  reducing  agents  used  to  effect  the  reduction 
in  alkaline  solutions.  C.  Rawson  considers  the  hyposulphite  reduction 
method  the  better  one  of  the  two.  In  carrying  it  out,  one  gramme  of  the 
finely-powdered  sample  is  made  into  a  paste  with  water  and  placed  in  a 
flask  with  about  six  hundred  cubic  centimetres  of  lime-water.  The  flask  is 
closed  by  a  cork  having  four  perforations,  two  of  which  serve  for  the  pas- 
sage of  coal-gas,  a  third  carries  a  siphon,  while  to  the  fourth  is  fitted  a  tap- 
funnel.  The  contents  of  the  flask  are  heated  to  80°  C.  and  one  hundred  to 
one  hundred  and  fifty  cubic  centimetres  of  a  strong  solution  of  sodium 
hyposulphite  (NaHSO2)  introduced  through  the  tap-funnel.  In  a  few 
minutes  the  liquid  assumes  a  yellow  tint,  and  is  maintained  at  a  tem- 
perature near  the  boiling-point  for  half  an  hour.  After  allowing  the  in- 
soluble matters  to  subside,  an  aliquot  portion  of  the  solution  should  be 
removed,  and  a  current  of  air  drawn  through  it  for  about  twenty  minutes,, 
when  it  is  acidulated  with  hydrochloric  acid.  The  precipitate,  which  con- 
sists of  indigotin  and  indigo-red,  is  collected  on  a  weighed  filter,  washed 
with  hot  water,  dried  at  100°  C.,  and  weighed.  It  is  then  exhausted  with 
boiling  alcohol,  whereby  the  indigo-red  is  dissolved  out  and  the  difference 
again  weighed  as  indigo-blue.  Ran  reduces  the  indigo  in  alkaline  solution 
with  glucose,  and  L.  M.  Norton  uses  milk  of  lime  and  zinc-dust  as  reducing 
agent,  and  then  takes  an  aliquot  portion  of  the  reduced  solution  to  reduce 
a  solution  of  iron-alum.  The  ferrous  salt  formed  corresponds  to  the  re- 
duced indigo  in  the  volume  taken,  and  is  determined  by  titration  with  a 
standard  solution  of  potassium  bichromate.  (For  details,  see  Helen  Cooley's 
article,  Amer.  Journ.  Anal.  Chem.,  ii.  p.  133.) 

For  the  reduction  of  the  indigo  in  acid  solution,  Bernthsen  and  Drew  * 
recommend  the  use  of  hyposulphite  of  soda  (]S"aHSO2),  and  claim  that 
the  reaction  is  a  quantitative  one  :  C16H8N2O2(SO3H)2  +  NaHSO2  +  H2O  = 
C16H10N2O2(SO3H)2  +  NaHSO3. 

C.  Rawson  f  considers  that  of  all  the  volumetric  methods  which  have 
been  devised  for  estimating  indigotin  the  hyposulphite  process  is  capable  of 
giving  the  most  rapid  and  accurate  results,  but  that  considerable  care  and 
delicacy  are  required  in  its  manipulation. 

Lee  J  has  proposed  the  sublimation  of  the  indigo-blue  as  a  method  for 
determining  its  percentage  in  commercial  indigo.  Other  writers,  however, 
do  not  agree  that,  unless  the  indigo  has  previously  been  somewhat  purified, 
the  results  can  be  depended  upon. 

*  Chem.  News,  xliii.  p.  80.  f  Allen's  Com.  Org.  Anal.,  2d  ed.,  iii.  p.  309. 

J  Chem.  News,  1.  p.  49. 


468 


NATURAL   DYE-COLORS. 


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BIBLIOGRAPHY   AND   STATISTICS. 


469 


C.  Rawson  *  has  given  the  following  results  with  commercial  samples, 
using  the  several  processes  just  detailed  : 


METHOD  USED. 

Java. 

Bengal. 

Bengal. 

Oude. 

Kurpah. 

Madras. 

Water    

2.99 

522 

6  17 

7  50 

8  05 

5  71 

Ash 

1  99 

3  91 

4  86 

8  91 

25  72 

33  62 

Indigotin,  by  sublimation  .... 
Indigotin,  volumetric,  by  hypo- 
sulphite   

60.84 
68  78 

57.50 
59  26 

49.36 
55  66 

41.60 
43  18 

41.92 
42  52 

39.56 
36  80 

Indigotin,  gravimetric,  by  ferrous 
sulphate  and  NaOH  

6824 

58  84 

54  34 

44  50 

41  50 

34  50 

Indigotin,  gravimetric,  by  hypo- 
sulphite and  lime   

68.97  1 

59  12\ 

56  201 

43  42  \ 

42  68  "1 

3521  \ 

Indirubin,  separated  bjr  alcohol   . 
Indigotin  and  indirubin,  titration 
with  KMnO4  direct 

4.23  f 
76  18 

3.50  / 
66  71 

2.80  / 
62  66 

365/ 
5004 

2.45  / 
47  15 

3.98  / 
39  50 

Indigotin  and  indirubin  titration 
after  precipitation  with  salt  .    . 

73.55 

63.50 

57.50 

44.90 

43.10 

37.40 

The  table  from  Damrner's  Chem.  Technologic,  Band  iv.  p.  591  (see 
opposite  page),  shows  the  characteristic  reactions  of  the  important  natural 
dyestuifs. 

V.  Bibliography  and  Statistics. 

BIBLIOGKAPHY. 

1873. — Die  Farbstoffe,  P.  Schutzenberger,  iibersetzt  von  C.  Schroeder,  2te  Auf.,  Berlin. 
1877. — Tropical  Agriculture,  P.  L.  Simmonds,  London  and  New  York. 
1880.— Lehrbuch  der  Farbenfabrikation,  J.  G.  Gentele,  2te  Auf.,  Braunschweig. 

Lexikon  der  Farbwaaren,  F.  Springmiihl,  Berlin. 
1881. — Les  Matieres  premieres,  Georges  Pennetier,  Paris. 
1882. — Dictionnaire  des  Alterations,  etc.,  Ed.  Baudrimont,  6me  ed.,  Paris. 

Manual  of  Colors  and  Dye-wares,  J.  W.  Slater,  London. 
1883. — Matieres  colorantes  et  ses  Applications,  Girard  et  Pabst,  Paris. 
1885. — The  Dyeing  of  Textile  Fabrics,  J.  J.  Hummel,  London. 

Die  Gesammte  Indigo-kupen-blau  Farberei,  etc.,  E.  Rudolf. 
1886. — Organische  Farbstoffe,  R.  Nietzki,  Breslau. 
1887.— Die  Gerb-  und  Farbstoif  Extracte,  S.  Mierzinski,  Vienna. 

The  Printing  of  Cotton  Fabrics,  A.  Sansone,  Manchester. 

Lexikon  der  Verfalschungen,  O.  Dammer,  Leipzig. 

The  Culture  and  Manufacture  of  Indigo,  W.  M.  Reid,  Calcutta. 
1889.— Das  Farben  und  Bleichen,  etc.,  Bd.  I.  Farbstoffe,  Dr.  J.  Herzfeld,  Berlin. 

Hand-book  of  Commercial  Geography,  Geo.  G.  Chisholm,  London. 

Handbuch  der  Farberei,  A.  Ganswindt,  Weimar. 
1890. — Les  Matieres  colorantes,  etc.,  C.  J.  Tassart,  Paris. 
1892. — Der  Indigo  vom  praktischen  und  theoretischen  Standpunkte,  Georgievics,  Wien. 

On  Indigo  Manufacture,  J.  B.  Lee,  London. 
1895. — Grundriss  der  Allgemeinen  Warenkunde,  Erdman-Konig,  12te  Auf.,  von  Hanau- 

sek,  Leipzig. 

1899. — Rohstoffe  des  Pflanzenreiches,  J.  "Wiesner,  2te  Auf.,  Leipzig. 
1900. — Die  Chemie  der  Natiirlichen  Farbstoffe,  H.  Rupe,  Braunschweig. 

STATISTICS. 

1.  INMGO  PRODUCTION  AND  EXPORTS. — The  annual  production  of 
natural  indigo  in  1890  was  estimated  to  be  as  follows : 

Bengal 4,000,000  kilos.,  valued  at  $10,000,000 

Madras 1,100,000     "             "      "       2,000,000 

Manila,  Java,  Bombay 1,000,000     "            "      "      2,500,000 

Central  America 1,125,000     "             "      "       3,000,000 

China  and  other  countries 1,000,000     "             "      "      2,500,000 


8,225,000 


$20,000,000 


*  Allen,  Commercial  Organic  Analysis,  2d  ed.,  iii.  p.  311. 


470 


NATURAL   DYE-COLOES. 


In  more  recent  years  the  cultivation  of  indigo  has  diminished. 
East  Indian  production  for  the  last  five  years  has  been  as  follows : 


The 


1895 162,000  maunds  (1  maund=  37.3  kilos.). 

1896 158,923        " 

1897 110,000        " 

1898 124,500        " 

1899 85,000        " 

According  to  Dr.  George  Watt's  report  to  the  Indian  government  there 
were  in  India  2762  indigo  factories  and  6032  vats,  giving  employment  to 
356,675  persons  during  the  working  season,  a  calculation  that  does  not  in- 
clude the  agricultural  labor  necessary  to  produce  the  plant.  (Journ.  Soc. 
Chem.  Ind.,  1894,  p.  994.) 

The  exportations  of  indigo  from  India  in  recent  years  have  been  as 
follows : 


1887-88. 
Chests. 

Germany,  Austria,  and  Holland    .    .  9,900 

England 6,300 

France,  Switzerland,  and  Italy  .    .    .  6,000 

Kussia 2,600 

America 7,500 

Arabia  and  the  Levant    .  700 


1888-89. 
Chests. 

10,836 
6,085 
3,965 
2,815 
9,263 
648 


1894-95. 
Chests. 

11,463 
8,931 
5,972 
1,815 
8,917 
2,876 


1897-98. 
Chests. 

8,740 
6,590 
4,160 
1,660 
6,940 
3,080 


Total 33,000        33,612        39,974        31,170 

2.  EXPORTATIONS  OF  DYE-WOODS. — The  exportations  of  several  of 
the  more  important  dye-woods  from  tropical  American  countries  for  the 
period  given  have  been  as  follows  : 

1.  Logwood  Exports  : 

From  Haiti.  From  Jamaica. 

Pounds.                Value.  Pounds.               Value. 

1882-83 152,288,713      .$1,998,789  66,685,584        $434,632 

1883-84  .....  154,775,887         2,031,434  100,638,496          655,921 

1884-85 142,986,254        1,876,695  126,795,200          743,774 

1885-86 114,341,436        1,500,731  142,256,128         927,165 

1886-87 105,000,065        1,378,125  132,009,472          932,089 

1887-88 106,163,734         1,393,399  226,108,912       1,718,627 

1888-89 57,021,431            748,406  258,616,960      1,816,035 

1889-90 70,801,241            929,266  133,232,400          962,432 

1890-91 56,743,891            744,764  244,794,592       1,861,395 

1891-92 39,766,320            521,933  194,152,784       1,476,320 

1892-93 ....  207,472,832       1,633,947 

2.  Fustic  Exports : 

From  Mexico. 
Pounds.  Value. 

1882-83 30,746,240          $280,988  7,477,792 

1883-84 32,995,200            248,656  4,024,272 

1884-85 17,471,509            128,019  2,078,160 

1885-86 17,420,099            110,873  3,526,768 

1886-87 24,942,407             178,621  9,366,000 

1887-88 26,583,858            177,488  5.518,016 

1888-89 18,224,030             133,952  2,777,216 

1889-90 23,762,671             198,646  1,457,200 

1890-91 16,927,020            119,631  2,128,112 

1891-92 13,187,368              96,588  1,517,152 

1892-93 ...  14,472,976 


From  Jamaica. 
Pounds. 


Value. 

$48,738 

21,857 

13,093 

21,071 

61,044 

35,964 

10,425 

8,606 

12,714 

9,888 

102,190 


BIBLIOGRAPHY  AND   STATISTICS. 


471 


3.  Exports  of  Brazil-wood  from  Bahia  during 

Ten  Years  Past: 

To 

To 

To 

To 

All  other 

United  States. 

England. 

Germany. 

France. 

countries. 

Total 

Kilos. 

Kilos. 

Kilos. 

Kilos. 

Kilos. 

Kilos. 

1884  .      584,318 

143,480 

15,000 

336,189 

56,350 

1,135,337 

1885  . 

232,912 

292,212 

49,568 

703,497 

. 

1,278,189 

1886  . 

684,002 

193,189 

134,857 

904,348 

18,569 

1,934,965 

1887  . 

783,616 

152,453 

46,640 

1,374,543 

.    .    . 

2,357,252 

1888  . 

388,631 

84,341 

18,584 

369,725 

. 

861,280 

1889  . 

149,063 

82,156 

753,457 

. 

. 

984,676 

1890  . 

58,121 

166,198 

78,959 

127,016 

430,295 

1891  . 

251,873 

670,857 

21,321 

944,051 

1892  . 

635,030 

64,676 

25,782 

1,093,650 

1,819J138 

1893  . 

615,158 

517,937 

147,177 

548,734 

'8,970 

1,837,976 

3.  IMPORTATIONS  OF  DYE-WOODS,  DYE-WOOD  EXTRACTS,  ETC. — The 
United  States  importations  of  dye-woods  and  natural  dyes  for  recent  years 
have  been : 

1896, 

Cochineal,  Ibs 161,330 

$50,988 
65,756 
$1,516,855 

32,338,264 


Valued  at 
Logwood,  tons  .... 

Valued  at 

Cutch  (catechu),  \1K 
Gambler,  / 1DS> 

Valued  at $1,158,611 

Indigo,  Ibs 3,340,001 

Valued  at $1,673,170 

Logwood  and  other  extracts, 

Ibs 4,839,111 

Valued  at $282,689 

Sumach  (ground),  Ibs.     .    .  13,432,041 

Valued  at $232,570 


1897. 

142,261 

$41,943 

33,362 

$611,010 


31,349,545 

$959,501 
3,522,016 

$1,696,641 

5,562,264 

$284,868 

18,688,635 

$248,048 


1898. 
158,055 
$45,762 
46,596 
$741,455 

42,334,590 

$1,021,341 

3,097,340 

$1,815,411 


1899. 

97,563 

$23,207 

37,375 

$546,274 

38,123,478 


4,084,672 
$256,176 

8,301,235 
$120,205 


$754,497 

3,127,357 

$1,698,583 

3,183,864 

$219,192 

12,975,970 

$183,136 


The  English  importations  of  dye-woods  and  natural  dye-colors  for  the 
last  four  years  have  been  : 

1896.                      1897.  1898.  1899. 

Cochineal,  cwt 5,697                 4,729  4,961  3,823 

Valued  at £36,658            £29,103  £29,407  £20,584 

Cutch  and  gambier,  tons  .          26,844              25,048  19,504  21,526 

Valued  at £548,756         £418,128  £304,998  £347,025 

Indigo,  cwt 89,941              82,526  53,838  58,977 

Valued  at £1,533,722       £1,470,574  £890,803  £986,090 

The  German  importations  of  dye-woods,  etc.,  for  the  last  four  years 
have  been : 

1896.                  1897.  1898.  1899. 

Met.  cent.       Met.  cent.  Met.  cent.  Met.  cent. 

Madder 920             1,074  1,172  623 

Quercitron 7,275           12,242  11,218  8,489 

Logwood 444,737        367,795  283,389  287,347 

Fustic 31,933          28,302  45,187  34,309 

Brazil-wood,  etc 34,186          23,570  18,279  13,016 

Cochineal        682                761  884  906 

Catechu  and  gambier 90,115           57,912  64,872  72,371 

Indigo 19,733          14,084  10,362  11,078 

Orseille  and  perseo 1,133             1,716  1,678  840 

Sumach 70,448           66,875  62,915  57,739 

Dye-wood  extracts 49,458          44,009  41,601  35,366 


472  BLEACHING,   DYEING,   AND   TEXTILE   PRINTING, 


CHAPTER   XIV. 

BLEACHING,    DYEING,    AND   TEXTILE   PRINTING. 

PRELIMINARY. — Prior  to  the  operation  of  bleaching,  except  in  cases 
where  delicate  shades  are  required,  it  is  always  necessary  to  thoroughly  cleanse 
the  fibre  or  fabric  of  grease  and  dirt.  For  cotton,  which  is  generally  handled 
as  hanks,  warps,  and  pieces,  it  is  sufficient  to  boil  it  in  a  dilute  solution  of 
caustic  soda  or  soda  ash,  followed  by  a  good  rinsing ;  it  may,  in  some  in- 
stances, be  boiled  in  plain  water,  wrung  out,  and  bleached  or  dyed ;  ordi- 
narily, however,  a  boiling  for  two  to  three  hours  in  a  bath  of  eight  to  ten 
per  cent,  of  crystallized  soda  and  one  to  two  per  cent,  of  soap,  calculated  to 
the  weight  of  the  cotton,  yields  good  result.  The  time  for  boiling  out 
cotton  is  much  reduced  if  it  is  immersed  in  a  weak  lukewarm  bath  of 
two  per  cent,  sulphated  oil  strongly  neutralized  with  ammonia  or  in  a  soap- 
bath  containing  ammonia.  This  is  found  to  completely  remove  all  natural 
oil  on  the  fibres  and  thoroughly  wet  them.  Wool  is  always  thoroughly 
scoured  both  before  and  after  it  is  manufactured  into  yarn.  The  soap  solu- 
tion generally  employed  contains  from  four  to  five  ounces  to  the  gallon  of 
water,  accompanied  usually  with  a  carbonated  alkali  (potash  or  ammonia) 
in  about  the  following  proportion  :  ten  per  cent,  of  soda  and  two  per  cent,  of 
soap.  The  temperature  of  the  bath  being  about  40°  to  50°  C.  (See  p.  307.) 
For  silk  (see  p.  312)  the  scouring-bath  contains  about  twenty-five  to  thirty 
pounds  of  Castile,  Marseilles,  or  other  neutral  soap  for  each  hundred  pounds 
of  silk,  and  a  temperature  at  or  near  the  boiling-point  is  taken  for  about  two 
hours,  turning  the  silk  occasionally.  For  some  colors  a  second  scouring  can 
be  employed  to  advantage,  only  one-half  the  quantity  of  soap  being  used  as 
in  the  first  bath.  It  is  the  practice  to  use  the  baths  several  times,  care 
being  taken  to  enrich  them  with  fresh  soap. 

A.  BLEACHING. — This  highly-important  operation  results  in  a  more  or 
less  complete  destruction  of  the  natural  coloring  matter  which  is  found  in 
all  fibres  of  industrial  importance.  Owing  to  the  somewhat  powerful 
action  of  most  of  the  agents  employed  for  the  purpose,  it  will  appear 
that,  unless  care  and  discretion  are  applied  to  their  use  on  the  part  of  the 
bleacher,  something  more  than  a  destruction  of  the  coloring  matter  will 
occur, — a  probable  partial  destruction  of  the  fibre.  The  operation  has 
been  known  since  the  earliest  times;  the  white  linens  of  the  Egyptians 
and  Phoenicians  were  much  esteemed  by  the  nations  trading  with  them. 
In  the  early  part  of  the  eighteenth  century  immense  fields  were  given 
up  wholly  to  bleaching  in  the  United  Kingdom ;  the  process  as  carried 
out  required  several  months,  consisting  of  a  successive  treatment  of  the 
cloth  or  fabric  in  alkaline  solution — termed  "  bucking" — and  washing,  then 
exposing,  while  damp,  and  spread  out  on  the  grass  to  the  sunlight  for  a 
few  weeks  (crofting),  immersing  in  sour  milk,  washing  again,  and  finally 
exposing  on  the  grass,  these  several  operations  being  repeated  until  the 
required  degree  of  whiteness  is  obtained.  Great  improvements  in  the  above 


BLEACHING. 


473 


FIG.  122. 


tedious  process  resulted  when  the 
use  of  sulphuric  acid  was  substi- 
tuted for  the  sour  milk,  and  chlo- 
rine gas  replaced  the  lengthy  field 
exposure,  this  latter  being  due  to 
M.  Berthollet ;  but  the  general  use 
of  this  substance  was  not  estab- 
lished until  the  manufacture  of  the 
now  familiar  "  chloride  of  lime"  or 
"  bleach."  Since  then  many  other 
bleaching  agents,  notably,  hydro- 
gen peroxide,  have  appeared,  but 
whether  they  will  ever  displace  the 
above  is  an  uncertainty. 

1.  Cotton  in  the  raw  or  unmanu- 
factured state  is  rarely,  if  ever, 
bleached ;  as  yarn,  however,  it  is 
continually.  The  hanks,  which 
have  been  previously  scoured,  are 
boiled  in  a  solution  of  chloride  of 
lime  (chemick)  from  one  to  two 
hours,  washed  well  in  water,  and 
passed  through  dilute  sulphuric 
acid  (1°  Tw.)  for  about  half  an 
hour,  and  finally  well  washed. 
These  operations  can  be  easily  con- 
ducted in  the  ordinary  wooden  tubs 
of  the  dye-house  in  places  where 
much  yarn  does  not  have  to  be 
bleached,  otherwise  special  arrange- 
ments should  be  provided.  Cotton 
warps  are  similarly  treated,  the  ap- 
paratus employed  being  a  contin- 
uous (warp)  dyeing-machine.  Cot- 
ton fabrics  require  much  care  and 
skill,  especially  those  intended  for 
domestic  use  in  the  bleached  condi- 
tion, and  also  those  which  are  to  be 
afterwards  dyed  or  printed  with  deli- 
cate shades.  The  method  of  bleach- 
ing, which  has  reached  a  high  state 
of  perfection,  is  the  so-called  "  mad- 
der-bleach/' from  the  fact  that  it  is 
employed  on  all  piece  goods  to  be 
printed  with  alizarin.  The  process 
detailed  and  illustrated  below  must 
not  be  accepted  as  the  exact  method 
followed  in  every  establishment, — 
it  being  remembered  that  nearly 
every  bleacher  has  his  own  modifi- 
cations which  he  introduces,  but  all 
yield  the  same  result.  The  opera- 


474 


BLEACHING,    DYEING,   AND   TEXTILE   PRINTING. 


tion  of  stamping  or  sewing  on  designating  marks  ;  sewing  the  pieces  together 
and  singeing, — a  removal  of  the  nap  or  down  from  the  cloth  by  means  of  a 
gas  flame  or  curved  hot  plate  ("  singeing-plate"), — need  not  be  detailed  here ; 
reference  may  be  had  to  special  works  on  textile  manufacture. 

Fig.  122  is  a  plan  of  part  of  a  bleach-house  for  cotton  cloth.  The 
goods  being  received,  they  are  passed  through  the  first  washing-machine,  on 
the  left  of  the  figure ;  this  operation  has  for  its  object  the  removal  of  loose 
dirt,  grease, — added  to  the  fabric  during  weaving, — and  other  matters; 
usually  the  goods  are  stacked  overnight  in  order  to  allow  an  incipient  fer- 
mentation to  take  place,  when  they  are  passed  several  times  through  the 
lime-wash  (milk  of  lime)  in  order  to  become  thoroughly  impregnated  with 
about  five  per  cent,  of  lime,  this  being  accomplished  by  means  of  rollers 
immersed  in  and  below  the  surface  of  the  lime-bath  and  a  pair  of  squeezing 
or  "  nipping  rollers." 

Following  the  liming  operation  is  the  boiling  ("  bowking")  in  kiers ; 
these  are  strong,  wrought-iron  cylindrical  vessels,  provided  with  a  series  of 
pipes,  and  in  some  cases  with  injectors,  which  enable  the  liquids  contained  in 
them  to  circulate  completely  through  the  cloth,  which  is  previously  intro- 
duced in  the  form  of  a  rope.  Fig.  123  is  a  vertical  section  of  a  single 

FIG.  123. 


injector-kier,  and  one  well  adapted  for  working  at  low  pressures.  Reference 
being  had  to  the  figure,  the  vessel  being  filled  with  the  fabric,  which  is  well 
laid  in,  the  liquid  is  admitted,  gradually  finding  its  way  to  the  false  bottom, 


30 


BLEACHING.  475 

through  which  it  passes  to  the  injector  at  a,  where  it  meets  a  steam  current, 
which  forces  it  upward  through  the  large  pipe,  finally  being  admitted  to  the 
kier  again  through  the  valve  6,  repeatedly  following  the  circuit. 

Barlow *s  high-pressure  kiers  are  usually  worked  in  pairs,  and  the  liquid 
is  forced  from  one  to  the  other  by  the  aid  of  steam.  This  kier  has  a  central 
perforated  tube,  through  which  the  liquid  passes  to  come  in  contact  with 
the  cloth.  Several  other  forms  of  kiers  are  in  use,  even  open  kettles  acting 
as  such,  the  object  being  the  same  in  each  case. 

The  length  of  time  the  cloth  remains  in  the  kier  varies  considerably,  in 
some  establishments,  where  a  high-pressure  is  used  (forty  to  fifty  pounds 
per  square  inch),  less  time  is  required, — five  to  six  hours  being  deemed  suf- 
ficient ;  again,  where  a  low-pressure  is  used  (eight  to  twelve  pounds)  the 
goods  are  allowed  to  remain  in  from  ten  to  twelve  hours.  From  this  boil- 
ing the  pieces  are  washed  in  water,  and  passed  through  dilute  hydrochloric 
acid  (specific  gravity  1.01  =  2°  Tw.), — the  bath  being  technically  termed  a 
"  sour."  The  pieces  are  slowly  worked  until  the  lime  is  completely  dis- 
solved, when  the  goods  are  thoroughly  washed,  or  until  every  trace  of  acid 
is  removed,  when  a  boiling  with  soap  and  soda  follows  in  kiers  exactly  as 
in  the  boiling  previously  mentioned.  For  each  hundred  pounds  of  cloth  a 
resin  soap  is  used,  made  with  five  to  six  pounds  of  soda  ash  and  one  to  two 
pounds  of  resin ;  the  soda  is  dissolved  in  two  gallons  of  water,  the  resin 
added,  and  the  whole  boiled  for  several  hours ;  for  each  pound  of  cloth  to 
be  acted  upon  one  gallon  of  water  is  used.  The  time  required  for  this  boil 
is  nearly  the  same  as  in  the  previous  boiling.  When  the  resin  soap  solu- 
tion is  run  off,  the  goods  are  boiled  for  three  or  four  hours  with  a  one  per 
cent,  solution  of  soda,  to  remove  the  soap  and  any  unconverted  resin  re- 
maining, followed  immediately  by  a  wash.  At  this  stage  of  the  process 
occurs  the  real  whitening,  or  bleaching,  of  the  goods, — the  so-called  "  ehem- 
icking" — requiring  much  care,  and  is  performed  with  a  solution  made  by 
dissolving  chloride  of  lime,  allowing  to  settle  and  become  clear,  the  super- 
natant liquor  alone  being  used.  The  strength  of  the  solution,  varying  from 
J°  Tw.  to  2°  Tw.  (specific  gravity  1.001  to  1.01),  being  used  cold,  or  but 
slightly  warmed,  in  the  latter  case  penetrating  the  cloth  better.  Repeated 
passage  of  the  goods  through  a  weak  solution  is  preferable  to  a  shorter  time 
in  a  strong  solution,  the  danger  from  injury  to  the  pieces  being  less.  The 
next  operation  may  be  (not  always)  a  wash,  and  then  a  souring  in  dilute 
(specific  gravity  1.01)  sulphuric  acid, — termed  a  white  sour, — after  which 
the  goods  are  allowed  to  remain  for  some  time  in  a  heap,  but  not  long 
enough  to  become  dry,  as  a  tendering  of  the  cloth  will  result ;  this  is  fol- 
lowed with  a  final  wash  to  remove  every  trace  of  acid,  passed  through 
squeezing  rollers,  and  over  revolving  cans  heated  by  steam,  to  dry.  The 
length  of  time  required  in  the  above  process  varies ;  if  the  goods  are  to 
receive  a  fine  clear  bleach,  or  are  to  receive  delicate  shades  in  dyeing  and 
printing,  four  or  five  days  may  be  necessary,  but  in  the  event  of  the  goods 
being  intended  for  full  shades,  half  that  time  will  answer. 

Mather- Thompson's  Process. — This  is  one  of  the  newer  processes,  and  is 
admirably  suited  for  warps  and  piece-goods.  The  goods  are  sewed  together, 
or  tied,  in  the  case  of  warps,  subjected  to  the  action  of  hot  caustic  alkali, 
washed,  and  transferred  to  wagons,  the  sides  of  which  are  of  iron  lattice- 
work (cages),  and  pushed  into  a  horizontal  kier^  and  for  five  hours  acted 
upon  by  a  solution  of  caustic  soda  (2°  to  4°  Tw.= specific  gravity  1.01  to 
1.02)  delivered  in  a  spray  and  at  a  pressure  of  four  to  five  pounds.  With- 


476  BLEACHING,   DYEING,  AND   TEXTILE   FEINTING. 

out  removing  the  goods  from  the  kier  they  are  washed  with  hot  water, 
removed,  and  rinsed  with  cold  water,  completing  the  scouring.  The 
bleaching  is  carried  out  in  a  continuous  apparatus  through  the  following 
stages : 

1.  Rinsing  with  warm  water. 

2.  First  chemick   bath  (chloride  of  lime  solution,  1  °  Tw.  =  specific 
gravity  1.005). 

3.  Passage  through  atmosphere  of  carbonic  acid  gas. 

4.  Washing  with  cold  water. 

5.  Worked  through  a  one  per  cent,  soda  solution  at  175°  F. 

6.  Second  washing. 

7.  Second  chemick  (chloride  of  lime  solution  .5°  Tw.). 

8.  Second  passage  through  carbonic  acid  gas. 

9.  Third  wash. 

10.  Through  one  per  cent,  hydrochloric  acid,  or  through  one  per  cent, 
of  a  mixture  of  hydrochloric  and  sulphuric  acid  (2:1). 

11.  Final  wash. 

In  this  process  the  real  bleaching  is  effected  by  the  hypochlorous  acid 
liberated  by  the  action  of  the  carbonic  acid  gas  upon  the  calcium  hypo- 
chlorite. 

Lunges  Bleaching  Process  differs  but  slightly  from  others  using  chloride 
of  lime,  except  that  he  increases  the  bleaching  action  by  the  use  of  a  small 
quantity  of  some  organic  acid, — preferably  acetic.  Chloride  of  lime  in 
contact  with  acetic  acid  forms  calcium  acetate,  with  evolution  of  free  hypo- 
chlorous  acid ;  this  gives  up  oxygen  during  the  bleaching,  leaving  hydro- 
chloric acid,  which  acts  on  the  calcium  acetate,  forming  calcium  chloride  and 
regenerating  the  acetic  acid.  The  hydrochloric  acid  never  being  in  the  free 
state  cannot  act  on  the  fibre ;  acetic  acid  has  no  action,  even  at  the  high 
temperature  or  pressure  used  in  bleaching. 

Hermite  Process  for  Electrolytic  Bleaching. — This  process  is  probably 
one  of  the  most  successful  yet  brought  forward,  embodying  the  use  of  elec- 
tricity, effecting  the  bleaching  by  the  decomposition  of  a  four  to  five  per 
cent,  solution  of  chloride  of  calcium  (not  "  chloride  of  lime,"  or  "  bleaching- 
powder"),  of  magnesium,  or  of  aluminum.  The  electrolyzed  solution  of  the 
salt  employed  is  of  especial  service  in  causing  the  destruction  of  the  coloring 
matter  of  vegetable  textile  fibres,  but,  owing  to  the  peculiar  effect  of  chlorine 
on  wool  or  silk,  it  is  impracticable  with  them.  Electrolyzed  salt  solutions 
are  replenished  by  the  addition  of  a  quantity  of  salt  equal  to  that  absorbed 
by  the  fibres  or  fabrics  when  withdrawn  from  the  bleach-bath. 

2.  Linen. — This  fibre  is  much  more  subject  to  the  destructive  action  of 
bleaching  agents  than  cotton,  in  consequence  of  which  the  same  process  is 
not  applicable,  and  also  on  account  of  the  greater  amount  of  impurities 
present,  chiefly  pectic  acid.  For  yarns  the  trade  distinguishes  three  im- 
portant grades  of  bleaching, — half,  three-quarters,  and  full  white,  to  obtain 
which  several  operations  are  necessary  : 

1.  Boiling  for  three  or  four  hours  in  a  ten  per  cent,  solution  of  soda 
ash,  or  in  a  six  per  cent,  solution  of  caustic  soda.     Wash,  rinse,  and  pass 
through  squeezing  rollers. 

2.  Pass  through  a  .4°  Be.  solution  of  chloride  of  lime,  and  work  or 
reel  one  hour,  and  wash. 

3.  Transfer  to  dilute  sulphuric  acid  for  one  hour  (one  part  acid  to  two 
hundred  parts  water). 


BLEACHING.  477 

4.  Boil  again  in  a  kier  with  two  per  cent,  caustic  soda. 

5.  Repeat  the  passage  through  chloride  of  lime  and  wash. 

6.  Final  treatment  with  sulphuric  acid  as  in  No.  3. 

The  above  will  produce  a  half-bleach,  and  by  repeating  the  three  final 
operations  afull  white  will  be  obtained.  Reeling  is  a  term  particularly  appli- 
cable to  linen-bleaching,  owing  to  the  way  the  yarn  is  handled,  the  result 
being  that  the  carbonic  acid  in  the  air  acts  upon  and  decomposes  the  chloride 
of  lime,  setting  free  hypochlorous  acid,  similarly  to  the  use  of  the  gas  in 
the  Mather-Thompson  process.  Linen  doth,  notwithstanding  many  trials, 
still  requires  much  longer  time  to  successfully  bleach  than  yarn.  It  is  quite 
possible  to  bleach  the  cloth  in  a  comparatively  short  time,  but  the  strength 
of  the  fibre  would  be  weakened.  The  following  outline  of  the  general  pro- 
cess indicates  the  successive  stages  : 

1.  Liming.     Boil  with  eight  to  ten  per  cent,  for  fourteen  hours  and 
wash. 

2.  Allow  to  remain  in  dilute  hydrochloric  acid  (specific  gravity  1.012) 
for  four  to  six  hours  and  wash. 

3.  Boil  with  resin  soap  (two  pounds  caustic  soda  and  two  pounds  resin) 
for  ten  hours,  followed  immediately  by  a  boiling  for  six  to  eight  hours  with 
one  pound  caustic  soda. 

4.  "  Grass."     Expose  on  the  fields  for  a  week  or  more. 

5.  "  Chemick."     Pass  through  chloride  of  lime  solution  of  J°  Tw.  for 
about  five  hours  and  wash. 

6.  "Sour."     Steep  in  dilute  sulphuric  acid  1°  Tw.  for  two  to  three 
hours  and  wash. 

7.  Boil  for  four  to  five  hours  with  .5  to  .75  per  cent,  of  caustic  soda, 
wash,  and 

8.  Expose  again  for  four  to  five  days  in  the  fields. 

9.  Second  chemick.     Same  as  No.  5,  only  J°  Tw.  for  five  hours. 

10.  If  necessary,  rub  with  a  soft  soap  between  "rubbing-boards"*  to 
remove  brown  spots. 

11.  Expose  again  on  the  grass  as  before. 

The  frequent  exposure  of  the  goods  on  the  grass  to  the  combined  action 
of  moisture,  air,  and  light  necessarily  dispenses  with  a  certain  amount  of 
the  chloride  of  lime,  besides  allowing  of  a  less  energetic  action. 

3.  Jute. — A  good  white  on  this  fibre  is  difficult  to  obtain.     Prior  to 
bleaching,  jute  is  scoured  with  a  five  per  cent,  solution  of  sodium  silicate 
(soluble  glass)  at  70°  C.,  washed,  and  bleached  with  a  solution  of  sodium 
hypochlorite  containing  about  one  per  cent,  of  available  chlorine,  made  by 
decomposing  bleaching-powder  with  carbonate  of  soda,  settling,  and  using 
the  clear  liquid.     The  goods  are  thoroughly  washed,  and  treated  in  a  dilute 
bath  of  hydrochloric  acid  (J°  to  1°  Tw.)  and  washed,  or  they  can  be  further 
acted  on  by  sulphurous  acid  by  immersing  in  a  bath  of  sodium  bisulphite 
for  two  to  three  hours,  and  dry.     Jute  can  also  be  bleached  by  being 
worked  in  a  solution  containing  one  per  cent,  permanganate  potash  (calcu- 
lated to  the  weight  of  its  material)  and  exposing  to  the  air  until  it  becomes 
brown,  when  it  is  immersed  in  a  solution  of  sulphurous  acid  and  washed. 

4.  Wool. — For  yarns,  etc.,  the  best  known  method  of  bleaching  is  "stov- 
ing," — that  is,  an  exposure  of  the  damp  goods  to  the  vapors  of  burning  sul- 

*  "  Rubbing  boards''  are  two  fluted  pieces  horizontally  placed,  the  upper  of  which  is 
moved  in  an  opposite  direction  to  the  course  of  the  cloth. 


478  BLEACHING,   DYEING,   AND   TEXTILE   FEINTING. 

phur,  confined,  usually,  in  a  frame  building ;  in  the  centre  of  the  floor  is 
mounted  an  iron  pot  in  which  the  sulphur,  in  rolls,  is  ignited,  by  means  of 
a  piece  of  iron  heated  to  redness  and  dropped  in.  From  six  to  eight  per 
cent,  of  sulphur  is  consumed,  and  the  time  required  is  about  eight  hours,  but 
for  carpet  yarns  and  goods  of  a  similar  grade  twelve  hours  may  be  neces- 
sary. The  yarn  is  removed  and  well  washed,  the  water  containing,  pos- 
sibly, a  little  carbonate  of  soda  to  neutralize  any  sulphurous  acid  remaining. 

For  piece-goods  the  same  process  is  applicable,  but  it  requires  arrange- 
ments for  passing  the  fabric  over  rollers  inside  the  sulphur-house  at  a  uni- 
form rate.  Piece-goods  can  also  be  bleached  according  to  two  somewhat 
lengthy  processes,  embodying  the  sulphuring  in  chambers,  detailed  in  San- 
sone's  "  Dyeing,'7  vol.  i.  p.  123. 

The  process  based  upon  the  action  of  hydrogen  peroxide  is  destined  to 
become  the  most  valuable  for  wool.  No  metal  should  be  exposed  in  the 
wooden  vats  in  which  the  bleaching  is  performed,  and  care  should  be  taken 
to  see  that  no  sediment  is  in  the  water-supply  pipe,  all  such  taking  up 
oxygen  from  the  reagent  and  thus  weakening  it.  A  solution  of  hydrogen 
peroxide  (equal  to  about  one  per  cent.,  and  capable  of  destroying  six  cubic 
centimetres  of  decinormal  potassium  permanganate  solution)  is  made  up 
in  the  vat,  and  this  is  carefully  neutralized  with  silicate  of  soda  which  has 
been  previously  diluted  with  warm  water ;  the  yarn  or  goods  is  immersed 
and  kept  below  the  surface  of  the  liquid  by  means  of  a  wooden  lattice 
frame.  The  temperature  must  not  be  above  the  normal.  In  a  few  hours 
the  color  of  the  wool  will  have  changed  to  a  white  or  nearly  so,  and  by 
keeping  it  in  a  "  wool  white"  will  be  obtained,  when  the  material  is  lifted, 
and  allowed  to  drain  back  into  the  vat,  when  the  liquid  is  brought  up  to 
the  original  strength  with  fresh  peroxide.  The  bath  can  be  kept  in  use  for 
six  months.  After  draining,  wash  in  water  containing  a  trace  of  sulphuric 
acid,  finally  with  water  alone. 

5.  Silk. — The  preliminary  operations  for  treating  this  substance  have 
already  been  mentioned.  Ordinarily,  silk  is  treated  in  a  similar  manner  to 
wool,  being  hung  on  poles  in  an  atmosphere  of  sulphurous  acid  for  several 
hours  (four  to  six),  taken  down  and  washed  ;  or  the  silk  can  be  worked  in  a 
bath  of  bisulphite  of  soda,  followed  by  a  weak  alkaline  wash  and  a  final 
rinse.  Aqua  regia  (hydrochloric  acid  and  nitric  acid,  5  : 1)  of  3°  to  4°  Tw., 
and  at  70°  Fahr.,  is  much  used  for  small  lots  ;  the  silk  being  constantly 
worked  for  about  twenty  minutes  when  the  bleaching  is  finished.  For  very 
fine  tints,  the  silk  is  entered  into  a  soap-bath  heated  from  85°  to  105°  Fahr., 
wrung  out,  and  hung  in  the  sulphur-house  for  ten  or  twelve  hours,  washed 
in  warm  and  cold  water,  and  dried. 

Tussah  silk  is  always  bleached  with  hydrogen  peroxide,  being  immersed, 
as  in  the  case  of  wool,  for  several  hours,  or  even  days.  When  the  necessary 
degree  of  whiteness  is  obtained,  the  silk  is  rinsed  and  dried.  Sansone  men- 
tions immersing  the  silk  in  strong  peroxide,  wringing  out  the  excess,  and 
steaming  in  a  closed  vessel.  This  method  has  yielded  good  results. 

J5.  BLEACHING  AGENTS  AND  ASSISTANTS. — Chloride  of  Lime  ("  Bleach- 
ing Powder"),  the  most  important  agent  for  bleaching  purposes,  is  produced 
in  immense  quantities  by  acting  on  dry  slaked  lime  with  chlorine.  It  occurs 
in  commerce  as  a  white  powder  possessing  a  characteristic  odor  resembling 
that  of  chlorine,  and  if  exposed  rapidly  absorbs  moisture.  The  real  strength 
depends  upon  the  amount  of  available  chlorine  obtainable, — ranging  between 
twenty-two  and  thirty-five  per  cent.  Solutions  of  the  above  sold  under 


BLEACHING.  479 

fanciful  names  are  met  with  in  the  trade  varying  in  strength  from  five  to 
eight  per  cent.  "  Chlor-ozone"  is  a  product  considerably  used,  and  is  essen- 
tially a  solution  of  sodium  hypochlorite. 

Permanganate  of  Potash  (K2Mn2O8),  although  not  strictly  a  bleaching 
agent,  is  mentioned  on  account  of  its  very  high  oxidizing  properties. 

Hydrogen  Peroxide  (H2O2)  is  a  colorless,  odorless  liquid  obtained  by  the 
action  of  hydrofluoric  acid  upon  barium  peroxide  in  a  lead-lined  tank. 
The  operation  is  conducted  at  as  low  a  temperature  as  possible,  and  with 
continuous  stirring;  in  about  twelve  hours  the  reaction  is  over,  and  the 
supernatant  liquid  drawn  off  and  preserved.  The  residue,  barium  fluoride, 
is  decomposed  with  sulphuric  acid,  and  the  hydrofluoric  acid  recovered.  It 
is  customary  to  refer  to  the  strength  of  hydrogen  peroxide  as  being  of  so 
many  volume  capacity,  six,  ten,  etc. ;  this  means  that  one  volume  of  the 
peroxide  will  yield  six,  ten,  etc.,  volumes  of  oxygen  gas. 

Sodium  Peroxide,  or  Sodium  Dioxide  (Na2O2),  is  coming  into  use  quite 
largely  as  a  substitute  for  hydrogen  dioxide,  as  it  is  in  many  respects  more 
convenient  to  use  and  can  be  kept,  when  properly  sealed  from  the  air,  for  a 
long  time.  It  is  a  yellowish-white  powder,  and  can  be  used  in  alkaline  or 
acid  solution. 

Soda  Ash  (Na2CO3). — This  is  the  commercial  anhydrous  carbonate  of 
soda,  used  principally  in  scouring.  It  is  generally  contaminated  with  vary- 
ing percentages  of  caustic  soda,  sodium  chloride,  sulphate,  etc.  Its  value 
depends  on  the  amount  of  Na2O  contained. 

Soda  Crystals  (Na2CO3.10H2O)  is  a  much  purer  and  more  expensive 
carbonate ;  it  contains  no  caustic  soda,  which  renders  it  well  suited  to 
scouring. 

Caustic  Soda  (NaOH). — It  comes  in  trade  in  iron  drums — solidly  filled 
— or  in  a  coarse  powder.  It  is  obtained  by  treating  carbonate  of  soda  with 
milk  of  lime,  whereby  the  carbonate  is  decomposed  with  formation  of 
calcium  carbonate,  when  the  clear  liquid  is  drawn  off  and  evaporated  down 
to  the  solidifying  point. 

Carbonate  of  Potash  (K2CO3)  is  not  used  in  the  dye  and  bleach  works 
to  the  same  extent  as  soda,  although  for  silk-  and  wool-scouring  it  leaves 
the  yarns,  etc.,  with  a  better  "  feel,'7  and  when  used  in  soaps,  it  does  not 
cause  colors  to  run  or  "  bleed"  to  the  same  extent  as  soda.  Its  value 
depends  upon  the  percentage  of  carbonate. 

Acids. — The  mineral  acids  are  used  in  bleaching  chiefly  to  neutralize 
alkalies,  or  to  cause  a  disengagement  of  hypochlorous  acid  in  the  so-called 
"  sours,"  and  reference  to  their  production  is  unnecessary.  Hydrochloric 
Acid  of  commerce  (also  called  Spirit  of  Salt,  or  Muriatic  Acid)  is  yellow 
in  color,  due  to  impurities.  The  general  strength  is  21°  Be.  (specific  gravity 
1.17).  Nitric  Acid,  used  in  conjunction  with  the  above  for  silk-bleaching, 
and  largely  in  the  preparation  of  some  mordants,  is  bought  with  a  gravity 
of  17.7°  Be.  (specific  gravity  1.140).  Sulphuric  Acid  (H2SO4)  is  obtained  by 
the  burning  of  sulphur  and  conducting  the  gas  into  lead  chambers,  in  con- 
tact with  nitrous  vapors  and  steam.  It  is  a  heavy,  oily-looking  liquid,  and 
when  pure  is  colorless.  It  is  ordinarily  sold  at  66°  Be.  (specific  gravity  1.84). 

Soaps. — The  soaps  employed  in  bleaching,  etc.,  embrace  Tallow,  Rosin, 
and  Olive  Oil  (for  silks),  although  others  are  used,  but  mainly  for  special 
purposes.  Reference  to  them  has  been  made  in  the  chapter  on  Oils  and 
Fats.  (See  p.  62.)  In  most  large  establishments  soap-boiling  appliances 
are  in  use. 


480  BLEACHING,   DYEING,   AND   TEXTILE   PRINTING. 

C.  MORDANTS  EMPLOYED  IN  DYEING  AND  PRINTING. — The  process 
of  mordanting  is  of  the  utmost  importance,  having  for  its  object  the  pre- 
cipitation of  some  substance  upon  the  fibre  which  has  an  affinity  for,  and 
will  effect  a  more  or  less  complete  fixation  of,  the  coloring  matter  used  for 
the  dyeing.  The  nature  of  the  mordanting  substance  used  depends  upon 
the  character  of  the  fibre,  the  kind  of  dye,  and  upon  the  effect  sought ; 
some  shades  require  the  use  of  several,  tinder  ordinary  circumstances 
wool  is  simply  boiled  in  a  solution  of  a  metallic  salt,  for  example,  bichro- 
mate of  potash  ("  chrome"),  in  the  presence  of  a  small  quantity  of  some 
acid,  in  this  case,  preferably,  sulphuric.  Wool  so  treated  is  said  to  be 
chromed,  and  is  in  a  condition  fit  to  receive  a  black  when  dyed  with  log- 
wood decoction.  Silk  is  mordanted  similarly,  lower  temperatures,  however, 
being  employed.  If  silk  and  wool  are  immersed  for  a  time  in  a  solution 
of  a  metallic  salt,  an  absorption  will  take  place,  when  the  fibre  can  be 
washed  in  \vater.  during  which  operation  a  deposition  of  a  basic  oxide  will 
occur.  Cotton,  unlike  wool  or  silk,  has  but  little  natural  affinity  for  the 
majority  of  coloring  matters,  and  of  necessity  must  be  specially  prepared. 
It  is  well  known  that  cotton  has  a  strong  tendency  to  combine  with  tannic 
acid,  and  this  is  made  use  of  by  steeping  cotton  in  a  solution  of  sumach  ex- 
tract, catechu,  or  other  tannin-yielding  material ;  if  it  is  afterwards  washed 
and  worked  in  a  bath  of  some  soluble  metallic  salt,  an  insoluble  compound 
will  be  formed,  which  then  has  the  property  of  uniting  with  the  dye.  It  is 
not  always  necessary  to  prepare  the  cotton  with  tannin,  an  immersion  in  the 
mordant,  followed  by  an  oxidation  or  ageing,  being  deemed  sufficient. 

Substantive  Dyeing  is  where  the  coloring  matter  is  taken  up  from  its 
solution  by  the  fibre  without  the  assistance  of  any  agent.  Wool  and  silk 
are  dyed  Avith  the  coal-tar  dyes  in  this  manner,  using  some  sulphate  of 
soda  and  sulphuric  acid  in  the  case  of  the  former,  and  with  a  soap-bath  and 
a  little  acetic  acid  in  the  case  of  the  latter.  Cotton,  when  dyed  with  the 
benzidine  colors,  also  comes  under  this  head  ;  it  is  possible  a  colored  com- 
pound of  cellulose  and  the  base  of  the  dye  is  formed.  The  use  of  salts  in 
dyeing  the  above  is  merely  to  prevent  a  too  rapid  absorption  of  the  dye  by 
the  fibre,  thereby  obviating  uneven  shades. 

Adjective  Dyeing  necessitates  the  intervention  of  mordants,  as  above  ex- 
plained. Albumen,  however,  does  not  cause  the  formation  of  an  insoluble 
precipitate  on  the  fibre,  but  causes  the  cotton  fibre  to  behave  towards  the 
dye  in  a  manner  similar  to  wool.  Many  coloring  matters  already  fixed  on 
cotton  have  the  valuable  property  of  serving  as  mordants  for  other  dyes,  a 
property  much  employed  in  the  production  of  compound  shades. 

The  following  list  of  mordants  embrace  only  those  of  prominence  and 
in  general  use ;  exact  methods  for  their  manufacture  will  be  found  in  the 
works  of  Hummel,  Sansone,  Herzfeld,  and  others. 

(a)  Mordants  of  Mineral  Origin. — Tin  Mordants. — These  are  first  in  im- 
portance to  the  dyer  and  printer.  They  are  used  in  two  states  of  oxidation, 
stannous  and  stannic.  The  former  salts  have  a  great  affinity  for  oxygen,  a 
property  of  considerable  value  as  a  discharge  for  other  colors.  Their  solutions 
are  colorless  or  nearly  so,  except  those  prepared  with  nitric  acid,  which  are  yel- 
lowish,— due,  possibly,  to  an  incomplete  oxidation  of  the  tin.  The  most  promi- 
nent tin  compound  is  Stannous  Chloride, — when  crystallized,  " tin  crystals" 
or  as  a  liquid  known  as  "  single  muriate  of  tin"  or  "  double  muriate  of  tin"  ac- 
cording to  the  gravity.  The  crystals  are  obtained  by  dissolving  feathered  tin 
in  commercial  hydrochloric  acid  and  evaporating ;  good  samples  contain  about 


MORDANTS.  481 

fifty  per  cent,  of  metal.  The  impurities  are  iron  (from  the  acid  used),  lead 
(from  the  crude  metal,  and  from  the  table-tops  on  which  the  crystals  are 
drained),  and  sometimes  copper.  The  "  muriates"  are  nothing  more  than  the 
mother-liquor  from  the  crystals,  diluted  for  "  single"  to  60°  Tw.  (specific 
gravity  1.3  =  about  thirty-eight  per  cent.  SnCl2.2H2O)  and  for  "double" 
to  120°  Tw.  (specific  gravity  1.6=  about  sixty-one  per  cent.  SnCl2.2H2O). 
The  above  are  chiefly  used  in  connection  with  the  natural  coloring  matters. 

Tin  Spirits,  owing  to  the  advent  of  the  tar-colors,  are  much  less  used 
than  formerly.  Their  composition  was  exceedingly  variable,  consisting 
usually  of  stannous  chloride,  with  or  without  additions  of  sulphuric,  oxalic, 
tartaric,  and  nitric  acids,  and  they  bore  such  names  as  Amaranth  Spirit,  Yellow 
Spirit,  Finishing  Spirit,  etc.  "  Stannous  Nitrate"  (nitrate  of  tin)  is  essen- 
tially a  solution  of  tin  in  nitric  acid,  the  chemical  composition  of  which  is 
doubtful.  "  Tin  spirits"  is  a  collective  name  for  a  long  list  of  stannic  com- 
pounds, made,  usually  by  the  dyer,  from  hydrochloric  and  nitric  acids, 
sodium  and  ammonium  chlorides,  etc.  Their  use  is  gradually  going  out. 
Stannate  of  Soda,  or  Preparing  Salt,  is  used  in  cotton-  and  woollen-printing ; 
its  value  depends  upon  the  amount  of  stannic  oxide  contained. 

Alumina  Mordants. — Sulphate  of  Aluminum,  also  known  as  Patent  Alum, 
does  not  find  much  application  in  the  dye-house,  but  is  considerably  em- 
ployed in  the  preparation  of  other  alumina  compounds  which  are,  being 
much  more  economical  than  potash  or  ammonia  alum.  It  is  obtained  from 
the  mineral  bauxite,  and  from  cryolite.  The  brand  manufactured  for 
paper-makers  is  the  purest,  containing  but  little  or  no  iron.  By  the  addi- 
tion of  alkaline  carbonates  the  normal  aluminum  sulphate  is  changed  into 
a  basic  sulphate  which  yields  alumina  to  the  fibre  more  readily.  Their 
application  to  cotton  is  followed  by  a  treatment  with  ammonia  or  soap  to 
fasten  the  alumina  more  fully,  to  wool  generally  with  cream  of  tartar, 
and  to  silk  by  immersion  overnight  in  the  solution,  followed  by  a  washing, 
which  causes  the  formation  of  a  basic  salt.  Aluminum  Acetate,  or  "  Red 
Liquor," — so  called  from  the  original  use  to  which  it  was  put,  dyeing 
reds, — is  obtained  by  the  double  decomposition  of  aluminum  sulphate  and 
calcium  or  lead  acetate  in  the  proper  proportions,  and  using  the  supernatant 
liquid.  Professors  Liechti  and  Suida,  and  Kochlin  have  conducted  elab- 
orate researches  into  the  action  of  the  aluminum  compounds  as  mordants, 
and  their  results  have  thrown  much  light  upon  the  whole  subject  of  mor- 
danting. Sulpho-acetate  of  Alumina  is  obtained  when  an  insufficient  quan- 
tity of  the  acetate  (lead  or  calcium)  is  added  to  decompose  the  alumina  salt, 
and  this  forms  the  red  liquor  of  trade.  Ordinarily,  the  solutions  have  a 
dark-brown  color  and  are  characterized  by  a  strong  pyroligneous  odor.  The 
cotton-dyer  and  printer,  especially  the  latter,  make  considerable  use  of  this 
mordant,  for  reference  to  which,  see  p.  478.  The  remaining  alumina  com- 
pounds— viz.,  chloride,  nitrate,  hyposulphite,  oxalate,  etc. — are  but  little  used, 
chiefly  in  calico-printing  for  alizarin  shades. 

Iron  Mordants. — Like  tin,  iron  is  employed  in  two  states  of  oxidation, 
— -ferrous  and  ferric.  Ferrous  Sulphate  (FeSO4.7H2O),  Copperas,  or  Green 
Vitriol,  occurs  as  a  by-product  from  several  chemical  processes,  and  is  much 
used  in  cotton-dyeing,  and  in  the  preparation  of  iron  mordants.  Ferrous 
Acetate,  also  called  Pyrolignite  of  Iron  and  Black-iron  Liquor,  is  manufac- 
tured similarly  to  the  acetate  of  alumina,  or  by  dissolving  scrap-iron  in 
crude  acetic  acid.  It  is  applied  in  the  same  general  manner,  and  to  the 
same  fibres,  as  the  alumina  compound.  The  remaining  iron  mordants  are  the 

31 


482  BLEACHING,   DYEING,   AND   TEXTILE   FEINTING. 

Nitrates  and  the  Nitro-sulphates.  The  former  are  obtained  by  dissolving 
scrap-iron  in  nitric  acid  to  the  proper  degree  of  saturation,  and  the  latter, 
by  treating  copperas  with  nitric  acid ;  as  an  iron  mordant  for  black  on  silks 
this  latter  is  probably  the  best,  from  the  fact  that  the  iron  exists  in  both 
states  of  oxidization. 

Chromium  Mordants  comprise  among  the  most  important  Bichromate  of 
Potash  and  Bichromate  of  Soda,  both  being  products  obtained  from  chromite. 
The  former  is  well  crystallized,  the  latter  is  quite  deliquescent,  frequently 
becoming  fluid  ;  in  price  it  is  cheaper  than  the  potash  salt,  and  yields  the  same 
results.  It  is  a  valuable  wool  mordant,  and  is  also  much  used  as  an  oxidiz- 
ing agent.  Chrome  Alum  (Potassium  Chromium  Sulphate)  is  a  residue  from 
the  manufacture  of  alizarin,  and  is  employed  as  the  basis  for  producing  many 
of  the  chromium  mordants.  Chromium  Acetate  is  obtained  by  double  decom- 
position of  lead  acetate  and  chromium  sulphate,  and  in  commerce  it  is  found 
of  about  30°  Tw.  (specific  gravity  1.15).  It  is  used  in  printing.  Other  com- 
pounds used  are  the  chloride,  sulphate-acetate,  and  alkaline  chromhydrate 
solution. 

Copper  Mordants  are  well  represented  by  the  sulphate  (blue-stone)  and 
the  nitrate.  Sulphate  of  Copper  is  used  in  dyeing  blacks,  mostly  in  con- 
junction with  other  mordants,  and,  owing  to  its  cheapness,  is  used  for  the 
production  of  nearly  all  the  copper  compounds.  Nitrate  of  Copper  is  easily 
prepared  by  dissolving  scrap-copper,  not  brass  (as  free  from  lead  and  solder 
as  possible),  in  nitric  acid,  and  diluting  to  1.4  specific  gravity.  In  cold 
weather  good  crystals  are  obtained,  but  they  absorb  moisture  very  rapidly. 
The  sulphide  and  acetate  find  little  application  except  in  special  cases. 

Antimony  Mordants. — Tartar  Emetic  (Antimony  Potassium  Tartrate)  is 
the  best  known  of  this  group,  and  is  much  used  for  fixing  tannin  in  cotton- 
dyeing.  Oxychloride  of  Antimony  is  another  form,  used  for  the  same  pur- 
pose. It  is  sold  as  a  concentrated  solution,  made  by  dissolving  metallic 
antimony  in  a  mixture  of  hydrochloric  and  nitric  acids  and  diluting  very 
cautiously  to  80°  Tw.  (specific  gravity  1.4).  Of  late,  double  fluorides  of 
antimony  and  potassium,  and  of  sodium  have  been  brought  on  the  market  as 
substitutes  for  tartar  emetic.  They  are  well  crystallized,  easily  soluble,  and 
cheaper.  The  mode  of  application  is  the  same  as  for  other  antimony  salts. 

Other  mordants  besides  those  above  mentioned  are  used,  but  not  as  ex- 
tensively, and  enough  has  been  said  to  indicate  their  general  nature ;  under 
the  operations  of  dyeing  the  special  uses  to  which  they  are  applied  will  be 
mentioned. 

(6)  Mordants  of  Organic  Origin. —  Tannin  (Tannic  Acid)  is  now  pro- 
duced in  large  quantities  of  exceptional  purity  for  use  in  the  arts,  and  offers 
to  the  dyer  a  convenient  mordant  in  place  of  many  tannin-yielding  sub- 
stances, which,  however,  still  hold  their  position  on  account  of  other  prop- 
erties. Tannin  is  much  used  by  the  cotton-dyer,  and  is  applied  generally 
in  two  ways :  first,  by  steeping,  and,  second,  by  padding.  For  silk,  tannin 
is  extensively  used  in  the  production  of  blacks,  and  also  for  weighting. 
Catechu,  or  Cutch  (see  p.  449),  is  used  in  a  similar  manner  to  tannin,  for 
the  production  of  browns,  drabs,  blacks,  and  other  shades,  in  combination 
with  bichromate  of  potash,  copper,  iron,  etc.  Catechu  is  bought  in  mats 
weighing  about  one  hundred  and  fifty  pounds,  and  also  as  "  cutch  extract," 
or  "  prepared  cutch,"  made  by  dissolving  the  crude  cutch,  straining  from 
sticks,  stone,  etc.,  and  evaporating  to  about  51°  Tw.  It  is  used  for  wool 
and  for  silk.  Sumach  (Shumach)  is  used  in  the  dye-house  in  the  ground 


DYEING.  483 

state,  and  as  an  extract,  which  is,  in  some  instances,  grossly  adulterated. 
Nutgalls,  rich  in  tannin,  find  extensive  application  both  in  dyeing  and 
printing,  especially  when  light  shades  are  to  be  fixed.  They  occur  whole, 
"  crushed/7  and  as  an  extract,  which  comes  usually  of  two  qualities.  My- 
robalans,  kino,  divi-divi,  etc.,  are  also  employed. 

D.  DYEING  AND  PRINTING. — 1.  Dyeing. — The  apparatus  used  by  the 
dyer  consists  of  vats,  kettles,  cisterns,  etc.,  and  are  ordinarily  constructed  of 
wood,  although  they  may  be  also  of  metal,  and  even  stone.  Their  capacity, 
in  case  of  woollen  yarn,  is  such  that  they  can  conveniently  accommodate  a 
hundred  pounds  of  material,  although  the  sizes  vary  according  to  circum- 
stances. Wooden  kettles  are  heated  by  a  copper  steam-coil  inside  and  on 
the  bottom,  and  are  provided  with  a  water-supply  pipe,  and  a  lifting  plug- 
valve  for  emptying.  Metal  kettles  are  preferably  heated  with  steam  by  a 
coil  or  double  bottom.  Open  fires  are  used  in  England  and  Europe  to 
some  extent,  but  in  the  United  States  very  rarely,  if  at  all.  The  shapes  of 
the  vat  or  kettle  vary  with  the  material  to  be  dyed.  For  cotton,  wool, 
and  silk  yarns  they  are  mostly  rectangular,  and  of  varying  depth,  for  loose 
material,  mostly  circular ;  in  the  case  of  indigo- vats  for  yarns,  they  are 
wine-pipes  stood  on  end ;  this  gives  a  great  depth  of  liquid  with  a  mini- 
mum of  exposure.  In  hand-dyeing,  the  yarn  is  hung,  and  worked  on  sticks 
laid  across  the  top  of  the  kettles ;  piece-goods  are  worked  by  means  of  a 
movable  winch,  sliding  as  occasion  requires  from  one  end  of  the  kettle  to 
the  other,  taking  care  to  guard  against  twisting  the  fabric.  Loose  material 
is  either  dyed  as  such  in  circular  tubs,  or  else  is  tied  up  in  bags;  and 
warps  are  passed  over  a  series  of  rollers  immersed  in  the  dye-liquor,  and 
then  between  squeezing  or  nipping  rollers. 

Of  primary  importance  in  successful  dyeing  is  a  regular  supply  of  pure 
water,  and  in  the  absence  of  this,  various  means  must  be  resorted  to  to 
purify  the  water  at  hand,  which  may  be  contaminated  with  sewage,  which 
may  not  render  it  unfit  for  use,  or  else  it  may  contain  lime  or  magnesia, 
usually  as  bicarbonates,  which  are  soluble,  or  it  may  have  sulphates  or 
chlorides.  Iron  (when  present  it  is  as  a  bicarbonate)  is  very  objectionable, 
and,  for  some  operations,  prevents  the  use  of  the  water.  Water  which  has 
flowed  through  limestone  regions  will  invariably  be  hard  from  the  lime  dis- 
solved, and  that  which  flows  or  is  pumped  from  granitic  regions  will  be  soft, 
due  to  the  absence  of  lime,  etc.  In  the  event  of  water  having  suspended 
matter,  this  can  be  easily  removed  by  suitable  filtration,  but  if  other  impuri- 
ties are  present,  chemical  purification  should  be  resorted  to.  A  hard  water 
is  one  which  has  bicarbonate  of  lime  or  magnesia  dissolved,  this  solution 
being  really  a  dissolving  of  carbonate  of  lime  in  carbonic  acid  contained  in 
the  water ;  besides  the  above,  it  may  contain  in  solution  sulphates  of  lime  or 
magnesia.  A  water  containing  no  sulphates,  if  boiled,  would  lose  its  hard- 
ness by  the  6icarbonate  splitting  off  into  carbonic  acid  gas  and  carbonate  of 
lime  or  magnesia,  which  would  be  precipitated  (temporary  hardness) ;  if  sul- 
phates were  present,  the  boiling  would  have  no  effect  on  them  (permanent 
hardness).  A  soft  water  is  one  containing  no  such  impurities. 

Chemical  Purification  for  water  embraces  several  processes,  notably  Dr. 
Clark's :  decomposing  the  bicarbonate  with  a  clear  solution  of  calcium 
hydrate,  by  this  means  the  excess  of  carbon  dioxide  is  combined  with  the 
lime  added,  which  is  precipitated  and  removed  by  settling.  Only  the  tem- 
porary hardness  is  removed.  The  Porter-Clark  process  is  similar  to  the 
above,  with  the  exception  that  the  precipitates  are  removed  by  the  water 


484  BLEACHING,   DYEING,   AND   TEXTILE   PRINTING. 

being  passed  through  a  filter-press.  Caustic  Soda  is  also  used  as  a  purifying 
agent,  which  removes  both  the  temporary  and  permanent  hardness.  The 
water  will  then  be  slightly  alkaline.  Alum  and  sulphate  of  alumina  are 
extensively  used  in  water  purification  for  dyeing  purposes.  The  alumina 
compound,  if  added  to  a  water  in  suitable  quantity,  is  completely  eliminated 
by  combining  and  separating  with  the  impurities. 

Solution  of  Coal-tar  Colors  requires  a  little  care,  because  if  imperfectly 
done  the  yarn  or  fabric  will  be  spotted  or  striped  :  effects  exceedingly  diffi- 
cult to  remove.  The  colors  are  dissolved  readily  in  warm  water;  some  may 
require  almost  a  boiling  temperature,  while  others  are  injured  when  highly 
heated.  They  ought  never  be  over  a  direct  fire.  In  all  cases  it  is  well  to 
strain  them  through  felt. 

Cotton-dyeing. — Two  operations  are  necessary,  mordanting  and  dyeing, 
except  in  indigo-dyeing,  where  no  mordant  is  required,  and  in  the  applica- 
tion of  the  benzidine  and  primuline  colors.  In  the  case  of  raw  stock,  the 
operations  are  conducted  in  large  circular  or  rectangular  vats,  heated  as 
previously  described,  and  provided  with  the  necessary  inlets  and  outlets  for 
water,  the  outlet  being  covered  with  a  gauze  screen  in  order  to  keep  the 
loose  material  from  stopping  it  up.  The  material  is  "  poled"  or  worked  by 
long-handled  rakes  or  by  mechanical  means.  The  washing  can  be  done  in 
a  similar  apparatus,  or  in  one  similar  to  a  wool-scouring  machine.  For  yarns, 
besides  the  open  kettles  mentioned  on  the  preceding  page,  many  mechanical 
devices  are  in  use,  and  are  well  suited  where  large  quantities  of  material  are 
to  be  worked  to  one  shade,  but  in  cases  where  different  shades  are  to  be 
produced,  hand-dyeing  cannot  be  excelled.  For  warps,  the  apparatus  re- 
ferred to  on  p.  456  is  used ;  it  can  be  made  with  two  or  more  kettles,  so  that 
the  warp  can  pass  through  two  or  more  different  solutions.  This  arrange- 
ment is  admirable  for  mordanting,  dyeing,  and  washing,  or  in  the  event  of 
using  the  primuline  colors,  requiring  rapid  treatment.  The  several  baths  can 
be  maintained  at  different  temperatures. 

Cloth-dyeing  Machinery. — The  vats  are  either  iron  frames  and  wood  or 
all  wood,  in  some  places  small  enough  to  stand  on  the  floor  of  the  dye- 
house,  in  others  they  must  be  sunk  below  that  level,  in  all  cases  surmounted 
with  a  hand  or  power  winch  for  working  the  pieces.  Drying  is  accom- 
plished by  wringing  cut  the  yarn,  centrifugating,  and  hanging  on  wooden 
sticks  in  a  "  dry-room,"  or  in  the  case  of  piece-goods,  squeezing  through 
rollers,  centrifugating,  and  carefully  arranging  on  sticks  as  above. 

Application  of  the  Natural  Coloring  Matters. — Indigo. — This  dye  is 
always  applied  in  the  cold,  and  by  any  of  the  several  "  vats"  now  known, 
among  which  the  lime  and  copperas  may  be  mentioned.  This  vat,  or  series 
(usually  ten),  is  made  up  in  various  proportions,  the  amount  of  ground 
indigo  ranging  from  thirty  to  thirty-eight  pounds,  copperas,  fifty  to  eighty- 
five,  lime,  eighty  to  ninety.  The  vats  being  filled  with  water,  the  lime  is 
added,  followed  by  the  ground  indigo  and  the  copperas,  raking  the  whole 
up  occasionally  until  the  indigo  has  been  reduced,  which  is  known  by  the 
olive-colored  appearance  of  the  liquid.  A  good  working  vat  is  known  by 
peculiar  blue  streaks  or  veins  which  appear  when  it  is  raked.  The  dyeing 
is  performed  by  dipping  the  wetted  yarns  in  the  oldest  (weakest)  vat,  then 
squeezed  out,  placed  aside  to  oxidize,  and  passed  through  the  next,  and  so  on 
until  the  proper  depth  of  shade  is  reached,  the  whole  operation  being  con- 
ducted systematically.  The  lime  which  is  precipitated  on  the  yarn  is  re- 
moved by  means  of  a  weak  acid  and  washing.  Piece-goods  are  dyed  in  a 


DYEING.  485 

similar  solution  by  fastening  the  material  to  a  large  frame,  which  is  dipped 
and  re-dipped  until  the  proper  shade  is  obtained,  or,  in  case  of  warps,  also 
by  passing  over  immersed  rollers  in  a  large  vat,  and  finally  over  rollers 
exposed  to  the  atmosphere ;  this  is  particularly  suited  for  light  shades. 

Zinc-powder  is  much  used  in  indigo-dyeing,  supplanting  copperas ;  for 
forty  pounds  of  indigo  about  twenty  pounds  of  zinc-dust  are  used.  This 
vat  is  more  economical  than  the  preceding.  Other  vats  are  also  employed, 
— viz.,  hydrosulphite,  Get-man  soda  vat,  urine,  etc.,  but  those  detailed  in- 
dicate sufficiently  the  character  of  the  operation. 

Logwood. — This  dye-wood  is  used  in  the  form  of  liquid  or  solid  extracts, 
and  as  chips,  and  mainly  for  the  production  of  blacks.  The  cotton  is  mor- 
danted in  a  cold  solution  of  acetate  or  nitrate  of  iron,  squeezed,  and  the 
iron  precipitated  on  the  fibre  by  passing  through  a  solution  of  carbonate  of 
soda,  and  boiled  in  the  logwood-bath ;  or  the  cotton  is  allowed  to  steep  in 
a  solution  of  tannin  (sumach,  galls,  etc.)  for  several  hours,  then  worked  in 
dilute  iron  solutions  as  above, — this  produces  a  tannate  of  iron, — followed 
by  a  passage  through  weak  lime-water,  and  dye  in  a  separate  kettle.  Ace- 
tate of  alumina  can  be  used  with  the  iron,  somewhat  modifying  the  shade. 
A  "  chrome  black"  can  be  obtained  by  dyeing  in  a  single  bath  of  bichromate 
of  potash,  hydrochloric  acid,  and  logwood  ;  many  modifications  of  this  pro- 
cess are  known.  Gray  shades  can  be  obtained  by  first  working  in  logwood, 
and  afterwards  in  the  copperas  or  bichromate  of  potash  baths. 

Of  the  red  dye-woods  little  need  be  said,  as  their  practical  utility  in  dye- 
ing is  on  the  decrease ;  their  coloring  matters  are  fixed  in  the  usual  manner 
with  tin,  alumina,  or  iron  mordants.  Of  the  yellows,  Quercitron  Bark  and 
Turmeric  are  the  most  important ;  the  former,  used  chiefly  as  an  extract,  is 
available  for  the  production  of  greens,  etc.,  in  combination  with  other  col- 
oring matters.  Turmeric  is  applied  directly  to  the  cotton  by  working  in  a 
plain  bath,  the  color  having  a  natural  affinity,  although  it  is  not  very  fast. 

Application  of  the  Artificial  Coloring  Matter  to  Cotton.* — In  this  section; 
only  the  individual  colors  will  be  referred  to,  any  attempt  to  discuss  the 
production  of  shades  by  compounding  would  be  beyond  the  scope  of  this 
publication. 

Fuchsine  is  dyed  upon  tannin-prepared  cotton,  or  upon  cotton  that  has 
been  worked  in  small  quantities  at  a  time  in  a  bath  of  ten  per  cent,  of  neutral 
soap  or  Turkey-red  oil,  followed  by  an  immersion  in  a  warm  bath  of  two 
hundred  and  fifty  gallons  water  and  one  gallon  acetate  of  alumina  (9°  Tw.). 
Work  half  an  hour,  wash,  pass  through  a  soap-bath  for  fifteen  minutes, 
wash,  squeeze,  and  dye.  The  color  is  added  in  successive  portions  until 
the  required  shade  is  obtained.  Sa/ranine  is  dyed  upon  a  tannin  mordant, 
or  the  tanned  material  is  worked  in  a  3°  Tw.  bath  of  stannous  chloride  for 
an  hour,  washed,  and  passed  through  a  two  per  cent,  soap  solution,  and 
dyed  at  140°  F.  Methyl  and  allied  Violets  can  be  dyed  upon  tannin  as 
above,  or  pass  the  un tanned  cotton  through  a  one  per  cent,  olive-oil-bath, 
squeeze,  and  dye  at  100°  F.,  or  with  the  assistance  of  acetate  of  tin,  or 
with  alum  and  soda.  The  basic  greens,  including  Victoria  Green,  Methyl 
Green,  Brilliant  Green,  etc.,  are  easily  dyed  upon  cotton  in  the  ordinary 
manner  with  a  little  (.5  per  cent.)  acetic  acid. 

The  Eosins,  with  Phloxin,  etc.,  are  dyed  in  several  ways  :  first,  by  pass- 

*  Reference  has  been  made  in  the  preparation  of  this  and  subsequent  sections  on  its 
applications  to  several  of  the  published  trade  circulars  issued  by  the  coal-tar  color  manufac- 
turers, and  also  to  information  from  private  sources. 


486  BLEACHING,   DYEING,   AND   TEXTILE   PRINTING. 

ing  the  cotton  through  a  two  percent,  soap-bath,  followed  by  an  immersion 
for  two  hours  in  from  two  to  three  per  cent,  acetate  of  lead,  washing  well, 
and  dyeing,  cold,  with  a  little  acetic  acid ;  or,  second,  by  working  in  a  dye- 
bath  with  eight  to  ten  per  cent,  sulphate  of  soda,  or  the  cotton  can  be 
worked  in  5°  Tw.  bath  of  stannate  of  soda  for  an  hour,  worked  for  thirty 
minutes  in  a  ten  per  cent,  alum  solution,  rinsed,  and  dyed  cold.  Rhodamin 
is  dyed  on  acetate  of  alumina  exactly  as  for  fuchsine.  Brilliant,  Cotton,  and 
Soluble  Slues.  The  cotton  is  tanned  and  dyed  with  five  per  cent,  alum  and 
one  per  cent,  soda ;  or  the  tanned  cotton  can  be  worked  in  a  3°  Tw.  stan- 
nous-chloride  bath  for  an  hour,  rinsed,  and  dyed  at  150°  F.  If  light 
shades  are  to  be  produced,  work  the  cotton  in  a  five  per  cent,  soap-bath  for 
an  hour,  squeeze,  and  work  in  a  three  per  cent,  tannin-bath,  wring  out,  and 
dye  with  the  assistance  of  tartaric  acid  and  alum.  Victoria  Blue.  Cotton 
is  mordanted  with  tannin ;  dye  with  one  per  cent,  acetate  of  alumina. 
Methylene  Blue.  This  is  an  exceedingly  valuable  color  to  the  cotton-dyer, 
as  with  it  he  can  produce  indigo  shades.  The  cotton  is  mordanted  with 
twenty-five  per  cent,  sumach  at  160°  F.  Give  several  turns,  and  allow  to 
steep  ten  hours,  wring  out,  and  work  for  twenty  minutes  in  two  and  one- 
half  per  cent,  tartar  emetic,  wash,  and  dye  in  a  bath  prepared  with  acetic 
acid  (three  per  cent.)  at  75°  F.,  gradually  raising  the  temperature  to  160° 
F.  Crocein  Scarlets  are  dyed  on  cotton  by  working  the  untanned  yarn  in 
stannate  of  soda,  wring,  and  pass  for  half  an  hour  through  sulphate  of 
alumina,  rinse,  and  dye.  Cotton  can  also  be  dyed  by  passing  first  through 
stannic  chloride,  and  then  through  acetate  of  alumina.  Dye  cold,  or  dye 
direct,  with  sulphate  of  alumina.  Auramin,  of  considerable  value,  is  dyed 
in  the  same  manner  as  methylene  blue.  Bismarck  Brown  and  Chrysdidine. 
Dye  same  as  safranine ;  temperature  100°  F.  Induline  and  Nigrosine.  Dye 
in  same  manner  as  for  the  cotton  blues.  Paraphenylene  Blue  is  dyed  upon 
tin  or  antimony,  and  tannin.  The  shades  produced  are  very  dark,  and 
extremely  fast ;  treated  with  bichromate  of  potash,  the  shade  closely  imi- 
tates, and  is  faster  than,  indigo.  The  substantive  colors  of  the  Congo  and 
parallel  groups  are  exceedingly  valuable,  for  the  reason  that  they  are  easily 
dyed  upon  unmordanted  cotton,  and  that  they  are  of  exceptional  fastness. 
The  several  Congos,  Benzo-  and  Delta-purpurin,  and  Rosazarin,  are  dyed 
with  two  and  one-half  per  cent,  soap  and  ten  per  cent,  sulphate  of  soda,  or 
phosphate  of  soda,  boil  for  one  hour.  Hessian  Purple  is  dyed  at  a  boil  for 
half  an  hour  with  ten  per  cent,  common  salt,  followed  by  a  passage  through 
dilute  soda.  Chrysamin  is  dyed  with  ten  per  cent,  sulphate  of  soda  and 
two  and  one-half  per  cent,  soap  at  a  boil.  Hessian  Yellow  is  dyed  with  ten 
per  cent,  of  salt  and  a  little  Turkey-red  oil.  Brilliant  Yellow  and  Chryso- 
phenin  are  dyed  with  ten  per  cent,  salt  and  two  per  cent,  oxalic  acid,  work 
half  an  hour,  squeeze,  rinse,  and  dry.  Azo  Blue,  and  Benzoazimine,  Helio- 
trope, etc.,  are  dyed  with  ten  per  cent,  sulphate  or  phosphate  of  soda  and  two 
and  one-half  pounds  of  soap,  let  stand,  and  skim  the  surface,  add  the  dye, 
boil,  and  put  in  the  yarn,  and  work  for  an  hour,  boiling,  rinse  the  yarn,  and 
dry  at  as  low  a  temperature  as  possible.  Indigo  shades  from  Benzoazimine 
are  obtained  as  above,  but  for  every  one  hundred  parts  of  color  add  three 
parts  Chrysamin.  All  the  benzidine  dyes  act  as  mordants  for  a  very  large 
number  of  other  colors,  no  other  fixing  agent  being  required. 

Aniline  Black. — This  color  is  produced  directly  upon  the  fibre  during 
the  dyeing  by  means  of  aniline  oil  in  the  presence  of  oxidizing  agents ;  to 
obtain  good  results  it  is  necessary  that  the  oil  used  should  be  as  pure  as  pos- 


DYEING.  487 

sible.  Two  methods  are  in  general  use, — warm  (Grawitz  patent)  and  the  cold. 
In  the  former  method,  two  thousand  four  hundred  litres  of  water,  thirty-two 
kilos,  hydrochloric  acid,  sixteen  kilos,  bichromate  of  potash,  and  eight  kilos, 
aniline  oil  are  taken.  The  acid  and  aniline  are  each  diluted  with  water  and 
carefully  mixed,  the  solution  thus  obtained  being  added  to  the  main  volume 
of  water.  The  bichromate  of  potash  is  previously  dissolved  and  added  after 
the  aniline.  Immerse  the  cotton,  and  work  for  three-quarters  of  an  hour  in 
the  cold,  and  then  gradually  raise  the  temperature  to  60°  or  70°  C.  In  the 
cold  method  take  eighteen  kilos,  hydrochloric  acid,  eight  to  ten  kilos,  ani- 
line oil,  twenty  kilos,  sulphuric  acid,  66°  Be\,  fourteen  to  twenty  kilos, 
bichromate  of  potash,  and  ten  kilos,  copperas.  This  bath  is  made  up 
similarly  to  the  previous  one,  with  the  exception  that  much  less  water  is 
used.  Aniline  salts  in  solid  form  are  often  used  instead  of  aniline  oil 
and  acid.  The  yarn  is  worked  in  one-half  of  the  materials  for  an  hour 
or  so,  after  which  the  remainder  is  added,  and  the  operation  carried  on 
for  about  one  and  a  half  hours  longer,  followed  by  a  washing,  and  a 
boiling  in  a  soap  solution.  In  either  case,  the  cotton  after  dyeing  is  sub- 
jected to  a  further  oxidization  with  bichromate  of  potash,  copperas,  and 
sulphuric  acid, — this  having  a  tendency  to  prevent  greening.  Chlorate  of 
soda  is  used  considerably  as  an  oxidizing  agent  in  the  dye-bath.  Vana- 
dium chloride,  or  vanadate  of  ammonia,  has  been  recommended  to  be  used 
with  a  chlorate  in  place  of  bichromate  of  potash ;  the  proportion  of  the 
vanadium  salt  being  to  the  displaced  bichromate  as  1 : 4000.  Another 
method  is  to  produce  the  aniline  black  in  powder  form,  purify  it,  liberate 
the  base,  which  is  dissolved  in  sulphuric  acid,  poured  into  water,  and  the 
precipitate  formed  thereby  dissolved  in  caustic  soda.  This  is  reduced  as  in 
the  case  of  indigo,  and  dyed  in  a  similar  manner. 

Alizarin-dyeing,  Turkey-red  Process. — J.  J.  Hummel,  in  his  "  Dyeing 
of  Textile  Fabrics,"  1886,  p.  427  et  seq.y  details  the  emulsion  process,  which 
need  not  be  described  here.  It  may  be  stated,  however,  that  beautiful  re- 
sults have  been  obtained  from  its  use ;  the  yarn  passes  through  fourteen 
operations,  as  follows :  boiling  in  soda  and  drying,  worked  in  an  emulsion 
of  oil,  dung,  and  carbonate  of  soda ;  passed  through  the  previous  process 
twice  again ;  worked  four  times  in  carbonate  of  soda,  steeped  in  water,  and 
in  carbonate  of  soda,  sumached,  mordanted  with  alumina,  dyed  with  aliza- 
rin (ten  per  cent.),  sumach,  and  blood,  cleared  with  carbonate  of  soda,  final 
clearing  with  soap  and  tin  crystals.  To  finish  the  dyeing  requires  about 
three  weeks,  but  a  real  Turkey-red  is  produced.  Except  for  some  grades 
of  goods,  it  is  doubtful  whether  such  a  lengthy  process  would  be  profitable. 

The  following  scheme  of  a  process  represents  the  type  of  a  reasonably 
short  one  ;  it  is  well  to  remember  that  it  can  be  modified  to  a  considerable 
extent  without  altering  its  product.  It  is  used  in  several  establishments 
essentially  as  given.  Boil  the  cotton  for  two  hours  in  a  1.04  specific 
gravity  solution  of  caustic  soda,  wash  well  in  water,  dry,  and  work  in  seven 
to  ten  per  cent,  solution  of  Turkey-red  oil,  squeeze,  dry  at  about  115°  to 
120°  F.,  steam  in  a  chest,  mordant  with  acetate  of  alumina  (red  liquor) 
at  80°  Tw.,  and  dry  as  before ;  work  for  an  hour  in  a  hot  bath  of  five 
pounds  of  dung  and  eight  to  ten  pounds  of  chalk,  followed  by  a  good 
wash,  and  pass  to  the  dye-bath,  made  up  of  eight  per  cent,  of  alizarin,  two 
per  cent.  Turkey-red  oil,  and  about  one  per  cent,  of  ground  sumach,  or 
equivalent  in  pure  extract.  Enter  cold,  and  slowly  increase  the  temperature 
to  and  maintain  it  at  160°  F.  for  over  half  an  hour.  Dry,  and  steam  in 


488  BLEACHING,   DYEING,   AND   TEXTILE   PRINTING. 

the  chest  as  above.    The  final  operation  is  a  soaping  with  carbonate  of  soda 
and  stannous  chloride  as  in  the  above  emulsion  process. 

An  almost  unlimited  number  of  processes  could  be  given,  but  it  is  hardly 
necessary,  the  principle  remaining  the  same  in  every  case.  For  full  in- 
formation reference  is  made  to  Hummel,  Sansone,  and  Knecht,  Rawson, 
and  Lowenthal.  The  apparatus  used  for  alizarin-dyeing  is  not  special, 
with  the  exception  of  the  machines  for  "  padding,"  the  material  to  be  dyed 
with  the  oils  and  for  working  in  the  liquors ;  the  most  important  is  the 
steam-chest,  which  is  essentially  a  large  cylindrical  wrought-iron  drum  with 
cast  ends,  one  of  which  is  provided  with  a  well-closing  door.  The  chest, 
or  steamer,  is  provided  with  a  steam-supply  pipe,  gauge,  and  safety-valve. 
The  yarn  or  cloth  is  hung  on  sticks  supported  on  rods  inside,  or,  as  shown 
in  Fig.  124,  mounted  on  iron  carriages.  Some  chests  are  so  built  that  the 

FIG.  124. 


yarn  contained  can  be  turned  while  closed  and  with  the  steam  pressure  on, 
which  seldom  exceeds  four  or  five  pounds. 

Ingrain  Red,  a  color  obtained  from  primuline  or  polychromine,  is  for 
some  purposes  a  perfect  substitute  for  Turkey-red,  being  fast  to  light,  soap, 
and  acids.  Primuline  is  dissolved  in  warm  water,  common  salt  or  sulphate 
of  soda  added,  and  the  yarn  worked  in  the  bath  until  a  good  full  yellow  is 
obtained,  when  the  material  is  washed,  and  immersed  in  a  cold  solution  of 
nitrite  of  soda  slightly  acidulated  with  either  hydrochloric  or  sulphuric 
acid,  this  causes  a  diazotizing  of  the  yellow  color,  with  the  production  of 
an  unstable  orange  shade ;  the  yarn  is  lifted  out,  washed  rapidly,  and  at 
once  dipped  in  a  warm  solution  of  0-naphthol  in  caustic  soda,  when  a  deep- 
red  color  is  developed.  The  yarn  is  worked  for  a  while,  and  afterwards 
well  washed  in  water.  If  phenol  or  resorcin  is  substituted  for  the  /5-naph- 
thol,  a  fast  yellow  and  orange  color,  respectively,  will  be  obtained.  The 
diazotized  yarn  is  very  sensitive  to  the  light,  if  it  is  not  in  a  reasonable 
time  developed,  no  color  will  be  obtained ;  this  fact  is  at  the  present  time 
experimented  upon  with  a  view  to  its  possible  use  in  photography. 

A  more  recent  and  still  better  substitute  for  Turkey- red  is  the  azo-para- 
nitraniline  obtained  by  diazotizing  para-nitraniline  C  and  developing  with 
ft  naphthol  and  red  developer  C.  The  cotton  yarn  is  preferably  first  im- 
pregnated with  the  caustic  soda  solution  of  the  developer,  made  with  the 
addition  of  castor  oil  soap,  and  then  put  in  the  diazotized  solution. 

Linen. — The  uses  to  which  fabrics  made  of  this  fibre  are  put  demand  colors 
that  shall  be  fast  to  washing,  light,  and  air ;  this  requirement  being  satisfied 


DYEING.  489 

by  alizarin  and  indigo.  The  coal-tar  colors,  as  a  rule,  are  not  applied, 
although  they  can  be  by  treating  the  fibre  in  the  same  manner  as  cotton. 

Jute,  owing  to  its  peculiar  chemical  structure,  does  not  require  any 
mordanting  ;  all  basic  colors  can  be  applied  by  simply  boiling  in  a  neutral 
bath.  Some  scarlets  and  a  few  of  the  acid  colors  are  fixed  with  the  assist- 
ance of  a  little  acetic  acid  in  the  dye-bath,  sometimes  with  a  little  sulphuric 
acid  and  alum. 

Wool-dyeing. — Raw  wool  is  dyed  in  the  same  manner  as  raw  cotton,  in 
open  kettles,  or  in  machines  made  for  the  purpose.  Woollen  yarn  and  cloth 
are  similar  in  their  manipulation  to  cotton,  the  apparatus  being  in  both  cases 
nearly  the  same.  Dyeing-machines  for  carpet  yarns  are  coming  slowly  into 
use,  several  forms  being  capable  of  handling  a  large  quantity  in  comparison 
with  hand  labor. 

Some  classes  of  goods,  i.e.,  plushes,  have  cotton  backs, — these  being 
previously  dyed  in  the  hank  and  warp  and  then  woven, — the  face,  or  pile, 
is  afterwards  dyed  the  proper  shade,  care  being  taken  to  select  such  colors 
as  will  have  no  modifying  effect  upon  the  cotton  color.  For  this  purpose 
cotton  dyed  with  aniline  black,  indigo,  or  alizarin  are  best  suited. 

Natural  Coloring  Matters  applied  to  Wool. — Indigo,  as  extract,  is  easily 
applied,  and  is  extensively  employed  in  the  production  of  light  and  dark 
shades  by  simply  boiling  the  wool  in  a  bath  made  up  with  the  color,  sulphuric 
acid,  and  sulphate  of  soda.  If  other  coloring  matters  are  to  be  used  in  con- 
nection with  the  above  for  the  production  of  compound  shades,  a  neutral  ex- 
tract had  better  be  used,  and  the  dyeing  done  without  the  above  acid.  Wool 
is  dyed  in  a  vat,  where  exceptionally  fast  and  full  shades  are  demanded,  espe- 
cially for  army  cloth.  Loose  wool  is  dyed  in  the  so-called  fermentation-vat. 
The  wool  being  kept  below  the  surface  of  the  liquor,  worked  about  by  means 
of  long  rakes  for  a  sufficient  time,  and  taken  out  and  put  in  large  cord  bags,  or 
placed  upon  rope  screens  to  drain  and  oxidize.  It  is  finally  dipped  in  very 
dilute  acid  to  remove  soluble  impurities,  well  washed,  and  dried.  Woollen 
yarn  is  worked  in  vats  exactly  as  in  the  case  of  cotton.  Cloth  is  worked  in 
the  vat  below  the  surface  of  the  liquid,  by  means  of  poles  with  hooks. 
The  best  indigo-dyed  cloth  is  that  made  from  wool  which  has  been  previ- 
ously dyed  in  the  raw  state, — dyed  in  the  wool. 

Logwood. — This  dyestuff  is  the  real  base  of  the  blacks  upon  wool,  the 
most  generally  followed  method  being  with  bichromate  of  potash  as  a  mor- 
dant. Boil  the  wool  in  a  bath  of  three  per  cent,  bichromate  and  one  per 
cent,  sulphuric  acid  for  an  hour,  lift  out,  rinse,  and  boil  in  a  bath  (made 
with  a  decoction  of  about  forty  per  cent,  chipped  logwood)  for  an  hour,  lift 
the  wool,  and  add  a  little  extract  of  fustic,  continue  the  boiling  for  a  half- 
hour.  This  will  yield  a  rich  black.  Various  modifications  are  practised, 
depending  upon  the  exact  shade  desired.  To  prevent  a  "greening,"  or 
development  of  greenish  tinge  on  exposure  of  the  goods  to  the  light,  a  coal- 
tar  color,  such  as  "  cloth  red,"  is  dyed  on  first,  so  as  to  neutralize  the  effect 
of  the  green  shade  which  may  form.  For  cheap  work  "  one-dip  blacks" 
are  used, — these  consist  chiefly  of  a  mixture  of  logwood  and  a  mineral  mor- 
dant, iron  or  copper.  Wool  can  be  mordanted  with  copperas,  copper,  and 
cream  of  tartar,  etc.,  followed  by  dyeing  in  the  logwood,  or  it  can  be  worked 
in  the  logwood  first,  followed  by  a  "  development"  in  a  bath  of  ferrous  sul- 
phate of  iron  and  copper. 

Logwood  Blue,  for  some  kinds  of  work,  is  an  excellent  substitute  for 
indigo,  full  shades  being  obtained  by  direct  dyeing,  or  by  dyeing  upon  a 


490  BLEACHING,   DYEING,   AND   TEXTILE   FEINTING. 

light  indigo  bottom.  Hummel  gives  the  following  method.  Mordant  the 
wool  for  one  to  one  and  a  half  hours  at  100°  C.  with  four  per  cent,  of 
aluminum  sulphate,  four  to  five  per  cent,  of  cream  of  tartar ;  wash  well, 
and  dye  in  a  separate  bath  for  one  to  one  and  a  half  hours  at  100°  C.,  with 
fifteen  to  thirty  per  cent,  of  logwood  and  two  to  three  per  cent,  of  chalk. 
The  addition  of  a  little  alizarin  or  tin  crystals  to  the  bath  at  the  termination 
of  the  dyeing  will  cause  the  appearance  of  "  bloom,"  peculiar  to  indigo. 

The  red  woods  are  fast  losing  ground,  although  before  the  introduction  of 
the  artificial  scarlets  and  cardinals  they  were  much  used.  Madder,  likewise, 
has  been  superseded  by  artificial  alizarin.  Wool  was  mordanted  for  browns 
with  bichromate  of  potash  as  for  logwood ;  for  reds,  mordant  with  alum,  or 
sulphate  of  alumina,  with  cream  of  tartar  (argols),  and  boil.  Tin  crystals 
and  tartar  produce  a  reddish-yellow.  These  colors  were  not  brilliant,  but  the 
value  of  them  depended  upon  their  fastness.  The  use  of  Cochineal  is  mainly 
for  the  scarlets  obtained  therefrom.  The  wool  is  mordanted  with  tin  crys- 
tals and  cream  of  tartar,  washed,  and  dyed  in  a  bath  with  five  to  ten  per 
cent,  of  cochineal  (ground)  for  an  hour.  Another  method  is  to  boil  the 
unmordanted  wool  in  a  bath  of  cochineal,  tin  crystals,  and  potassium  oxalate 
for  an  hour.  For  scarlets  with  a  bluish  cast  (crimsons)  the  wool  is  mordanted 
with  aluminum  sulphate  and  cream  of  tartar,  or  the  wool  can  be  mordanted 
in  a  bath  containing  tin  crystals,  tartar,  and  aluminum  sulphate,  followed 
by  the  dyeing  in  a  separate  bath.  Copper,  or  iron,  as  a  mordant  will 
produce  dark  shades,  and  as  impurities  in  the  dye-baths  will  have  a  sad- 
dening effect  upon  the  color  obtained.  Fustic  is  largely  used  in  wool-dye- 
ing, chiefly,  however,  in  combination  with  other  colors, — i.e.,  indigo  extract 
to  produce  greens,  olives,  sages,  etc.,  and  always  upon  mordanted  wool, 
using  tin  crystals,  sulphate  of  alumina,  bichromate  of  potash,  iron,  and 
copper.  Quercitron  Bark  is  used  for  the  same  purpose  as  fustic  and  under 
the  same  conditions.  Flavin,  a  production  of  the  latter,  is  used  in  the  same 
manner,  its  chief  advantage  is  that  it  is  much  more  concentrated.  Archil 
(Orchil)  as  "extract,"  liquor,  or  paste  is  extensively  used  in  the  dyeing 
of  carpet  yarns ;  it  is  applied  by  simply  boiling  the  yarn  in  a  bath  with 
the  color,  sulphuric  acid,  and  sulphate  of  soda.  It  is  exceedingly  difficult 
to  remove  from  yarn  once  dyed  with  it ;  a  process  which  will  economically 
accomplish  this  is  much  sought  after  by  manufacturers. 

Application  of  the  Coal-tar  Colors. — As  a  general  rule,  it  may  be  stated 
that  nearly  all  the  soluble  artificial  colors  can  be  dyed  upon  wool  without 
any  special  treatment,  by  boiling  in  a  bath  with  ten  per  cent,  of  sulphate  of 
soda  and  two  to  four  per  cent,  of  sulphuric  acid.  A  few  exceptions  may 
be  given  :  Alkali  Blue  (Nicholson's  Blue).  The  color  is  dissolved  in  rar- 
bonate  of  soda,  poured  into  the  dye-bath,  the  wool  entered,  and  the  tem- 
perature raised  to  the  boil,  keep  boiling  for  a  while,  lift,  rinse  well,  and 
immerse  in  a  bath  of  very  dilute  sulphuric  acid,  when  the  color  will  be  at 
once  developed.  The  Violets  (Hofmann's,  etc.)  are  dyed  neutral,  or  with  a 
little  soap.  Methyl  Green  is  applied  to  wool  with  borax,  after  having  been 
mordanted  with  hyposulphite  of  soda  and  hydrochloric  acid.  Auramine 
is  dyed  both  neutral  and  acid.  The  Indulines  are  dyed  neutral,  and  then 
boiled  in  dilute  sulphuric  acid.  Gallein  and  Ccerulein  are  dyed  upon 
wool  mordanted  with  potassium  bichromate  and  a  small  quantity  of  acetic 
acid.  The  application  of  Alizarin  to  wool  is  exactly  as  for  madder,  the 
general  mordant  being  sulphate  of  alumina  and  tartar  for  reds  ;  tin  crystals 
and  tartar  for  orange ;  potassium  bichromate  and  sulphuric  acid  for  red- 


DYEING.  491 

browns;  iron  and  tartar  yield  violet;  and  copper,  shades  of  brown.  The 
addition  of  a  little  lime  to  the  dye-bath  is  necessary  in  case  none  is  naturally 
present  in  the  water. 

Nitro-alizarin  (Alizarin  Orange)  produces  with  several  metallic  mor- 
dants, applied  as  above,  a  range  of  shades,  which  have  not  reached  commer- 
cial importance.  Alizarin  Blue  is  dyed  upon  a  chromium  mordant,  and 
yields  a  durable  blue,  of  some  value, — for  wool,  the  price  of  the  dye  is 
against  it. 

Alizarin  blues,  snch  as  Alizarin  Blue  H  R,  which  are  made  by  com- 
bining alizarin  or  a  derivative  of  the  same  with  a  base,  such  as  aniline,  give 
various  fast  shades,  and  are  dyed  nearly  the  same  as  the  older  alizarin  blue 
and  alizarin  blue  S,  except  that  the  bath  may  be  exhausted  with  very  little 
or  no  acid. 

The  mineral  colors  are  dyed  upon  fibres  through  the  decomposition  of 
metallic  salts,  for  example,  to  dye  Prussian  Bluey  the  wool  is  worked  in  a 
bath  of  red  prussiate  of  potash  and  sulphuric  acid,  and  gradually  brought 
to  a  boil,  squeezed,  rinsed,  and  dried. 

Silk-dyeing. — Silk  has  a  great  affinity  for  the  coal-tar  colors,  with  which 
it  can  be  dyed  without  any  mordant,  although  it  is  customary  to  employ  a 
soap-bath  (boiled -off  liquor)  with  or  without  the  addition  of  a  weak  acid, 
usually  acetic.  If  soap  is  not  used  the  colors  will  appear  streaky  or  spotted. 
For  ribbons,  fancy  dress  goods,  plushes,  etc.,  the  above  colors  are  solely 
employed,  with  the  possible  exception  now  and  then  of  recourse  to  some 
natural  coloring  matter,  the  use  of  the  latter  being  almost  restricted  to 
logwood  for  blacks  and  modified  shades,  including  browns.  Silk  is  dyed 
in  skeins  or  hanks,  warps,  or  pieces,  this  latter  including  plushes.  The 
machinery  is  of  the  simplest  kind,  embracing  the  kettles,  with  and  without 
winches,  washing-machines,  etc.,  and  need  not  be  especially  described. 

Silk  is  not  dyed  with  indigo  (vat  process).,  but  indigo  shades  are  obtained 
by  using  indigo-carmine.  Black  is  obtained  by  several  processes.  Work 
the  silk  in  acetate  of  iron  and  wash,  then  in  a  warm  soap  solution,  followed 
by  an  immersion  in  ferrocyanide  of  potash,  washed,  and  worked  again  in 
the  iron-bath,  rinsed  well,  and  steeped  in  a  solution  of  catechu  or  gambir 
for  ten  or  twelve  hours  and  washed.  This  preliminary  process  is  necessary 
in  order  to  insure  a  good  result  if  systematically  carried  out  and  not  forced. 
The  material  is  dyed  in  a  logwood  decoction  containing  soap. 

To  obtain  heavily  weighted  goods,  the  process  of  dipping  in  iron  solu- 
tion and  then  in  tannin-containing  liquors  is  often  repeated  several  times. 
A  method  giving  excellent  results,  and  which  is  considerably  used,  is 
as  follows.  Wash  the  goods,  and  pass  through  a  bath  of  nitrosulphate 
of  iron,  wash,  and  then  through  a  solution  of  carbonate  of  soda.  These 
two  operations  are  repeated  several  times,  each  time  causing  the  precipita- 
tion of  more  iron  upon  the  fibre,  and  consequently  "  weighting"  the  silk. 
Work  for  some  time  in  a  bath  of  ferroprussiate  of  potash  and  then  in  a 
bath  of  catechu,  followed  with  a  little  "  muriate  of  tin"  or  tin  crystals, 
wash,  and  transfer  to  the  logwood-bath,  which  may  contain  a  little  extract 
of  fustic  to  modify  the  shade  required,  then  to  a  soap-bath.  Every  locality 
is  not  suited  to  black  silk-dyeing  on  account  of  impurities  in  the  water, 
careful  purification  of  which  is  a  special  requisite.  Seal  plushes  are  dyed, 
first  in  a  dye-bath  in  the  ordinary  manner,  a  dark-brown  shade,  followed 
by  the  application  of  a  black,  blue-black,  or  other  color,  in  the  form  of  a 
paste  thickened  with  starch,  gum,  or  other  medium.  The  application  of 


492  BLEACHING,    DYEING,   AND   TEXTILE   PRINTING. 

this  being  done  on  a  machine  provided  with  revolving  brushes,  and  so  regu- 
lated that  only  the  tip  or  face  of  the  piece  of  goods  is  coated.  One  impor- 
tant feature  in  plushes  of  this  character,  and  also  in  other  kinds  of  silk 
goods  which  have  been  heavily  iron-mordanted,  is  that  the  natural  lustre 
of  the  fibre  is  somewhat  destroyed ;  this  is  supplied  by  means  of  a  paste 
mixture  of  vegetable  oils  made  into  a  paste  with  starch  or  other  substance, 
applied  as  in  the  case  of  the  tip,  and  steamed  in  an  apparatus  similar  to 
that  used  for  alizarin  red  (p.  488).  The  oil,  usually  a  definite  amount, 
is  absorbed  by  the  silk  fibre  under  the  influence  of  steam,  imparting  a  per- 
manent lustre.  The  goods,  when  removed  from  the  steamer,  are  washed  to 
remove  the  starch,  excess  of  oil,  etc.,  when  they  are  ready  for  other  opera- 
tions. 

The  weighting  of  silk  is  accomplished  by  the  use  of  iron,  as  explained 
above.  This,  however,  is  suitable  for  dark  shades  only ;  for  light  shades, 
tin  in  combination  with  sodium  phosphate  and  soap  is  used. 

A  class  of  fabrics  similar  to  plush,  but  with  the  pile  of  two  or  even 
three  colors,  much  used  for  carriage-robes,  etc.,  and  dyed  to  imitate  the  skins 
of  animals,  are  prepared  in  the  following  manner :  The  material  (cotton- 
black  and  silk  pile,  the  former  previously  dyed  a  fast  color)  is  dyed,  say 
a  brown,  in  the  ordinary  manner ;  upon  the  fibre  is  then  applied  a  dis- 
charge made  of  stannous  chloride  solution  and  permanganate  of  potash. 
This  is  so  controlled  that  only  one-half  of  the  fibre  is  acted  upon.  When 
the  effect  is  produced  the  excess  is  washed  off,  rinsed,  dried,  and,  if  neces- 
sary, a  tip  is  applied,  which  only  dyes  the  very  face  of  the  pile.  In  this 
manner  three  colors  are  obtained  on  each  thread  of  the  face.  After  treat- 
ing as  above,  the  whole  may  be  dyed  a  very  light  shade,  thereby  producing 
modified  effects. 

The  artificial  coloring  matters  are  applied  to  silk  as  previously  stated. 
Nicholson's  Blue  (Alkali  Blue)  is  applied  as  directed  for  wool,  and  seldom  for 
the  production  of  mixed  shades.  Picric  Add  is  much  used  for  compounding, 
especially  for  greens,  faster  colors  can  be  obtained  by  using  naphthol  yellow 
and  indigo-carmine.  The  Eosins  yield  beautiful  colors,  and  are  applied  in 
a  soap-bath  followed  by  a  brightening  in  dilute  acid.  The  Azo  dyes  are 
applied  with  a  neutral  soap-bath. 

The  use  of  Alizarin  with  silk  is  only  in  cases  where  fastness  is  of  more 
importance  than  brilliant  shades.  Alizarin  Black  is  being  much  used  in 
dyeing  mohair  goods  (astrachans),  and  is  applied  in  the  ordinary  manner. 

E.  PRINTING  TEXTILE  FABRICS. — A  brief  outline  of  the  more  impor- 
tant "  styles"  in  use  is  all  that  will  be  attempted  in  this  section,  from  the 
fact  that  the  subject  is  too  extensive  to  enter  into  the  details  satisfactorily. 
The  processes  in  general  are  conveniently  divided  into  two  main  groups, 
differing  in  the  manner  of  applying  the  colors, — namely,  Direct  Printed 
Colors,  Dyed  Colors. 

Direct  Printing  is  done  by  mixing  the  desired  color  with  the  proper 
fixing  agents  and  applying  directly  to  the  fabric  by  means  of  blocks  en- 
graved with  the  design,  or  in  a  machine  provided  with  a  cylinder  upon 
which  the  design  is  likewise  engraved ;  for  each  color  to  be  applied  a  sepa- 
rate cylinder  is  needed.  From  the  above  it  is  obvious  that  the  color  so 
applied  will  appear  only  on  those  portions  of  the  fabric  brought  in  contact 
with  the  design. 

Dyed  Colors  are  obtained  by  printing  different  mordants  upon  the  cloth, 
as  above,  and  fixing  as  for  ordinary  cloth,  and  then  dyeing  the  whole,  or, 


TEXTILE   PRINTING. 


493 


FIG.  125. 


by  printing  upon  the  cloth  resists,  substances  which  will  prevent  the  dye 
from  becoming  fixed  at  those  places  so  printed,  or,  again,  by  dyeing  the 
whole  piece  first,  and  then  producing  patterns  or  designs  by  means  of  sub- 
stances which  will  destroy  the  ground-color  whenever  brought  in  contact ; 
these  substances  are  called  discharges.  This  broad  definition  is  deemed  suf- 
ficient for  the  purpose  intended  ;  the  principle  of  each  style  will  be  apparent 
upon  following  the  methods  hereafter  given. 

The  operations  conducted  in  a  print-works  embraces  as  a  preliminary 
bleaching,  the  details  of  which  are  referred  to  on  p.  473.  Then  the  prep- 
aration of  the  colors,  which  is  always  done  in  copper  pans  mounted  in 
such  a  manner  that  they  can  be  emptied  easily,  and  that  their  contents  can 
be  boiled  by  steam,  and  cooled  by  water,  facilities  for  this  being  done  by 
means  of  steam  and  water  trunnions  connecting  with  the  double  bottom  of 
each  pan.  From  five  to  eight  pans  are  supplied  in  a  "  battery/'  although 
it  is  often  convenient  to  have  one  or  more  pans  separately  mounted,  and 
without  steam  taps.  The  agitation  of  the  contents  is  performed  either  by 
means  of  wooden  paddles  or,  preferably,  by  mechanical  agitation,  which 
can  be  raised  clear  above  the  top  of  the  pan,  and  without  interfering  with 
the  working  of  the  others.  As  the  majority  of  colors  used  are  made  with 
either  starch  or  flour  for  thickening,  it  is  necessary,  to  insure  good  results, 

that  they  are  strained  or  filtered ;  for  this 
purpose  it  is  well  to  have  wooden  frames 
made,  over  which  is  tacked  brass  or  copper 
wire  cloth  (iron  is  inadmissible).  The  most 
important  piece  of  apparatus  is  the  printing- 
machine,  an  idea  of  the  construction  and 
operation  of  which  may  be  had  from  Fig. 
125.  A  is  a  cylindrical  "bowl"  or  drum, 
covered  with  several  thicknesses  of  felt 
cloth,  c,  around  this  drum,  and  passing  over 
a  smaller  one,  B,  is  an  endless  band,  d  (full 
width  of  the  machine),  over  this  band,  and 
acting  as  a  guide  to  the  fabric  to  be  printed, 
is  another  band,  e,  which  serves  to  keep  d 
clean,  being,  in  fact,  a  piece  of  cloth,  yet 
to  be  bleached  and  printed  ;  the  piece  being 
printed  is  indicated  by/.  The  means  for 
applying  the  color  are  shown  in  the  figure 
below  the  large  drum, — viz.,  the  printing 
rollers  or  engraved  cylinders  hly  h2,  A3,  which 
are  fed  with  color  through  coming  in  con- 
tact with  the  wooden  rollers  nly  n2,  nB,  which 
dip  in  the  color  contained  in  the  troughs 
&i,  ^2>  ^3«  Pressing  against  each  of  the 
rollers,  A,  is  shown  a  small  strip  of  metal, 
r,  technically  termed  the  "doctor,"  the 
purpose  of  which  is  to  remove  the  excess  of 
color  from  the  face  of  the  printing-rollers 
before  they  come  in  contact  with  the  cloth. 
These  "  doctors"  are  best  made  of  bronze 
or  gun-metal,  or  some  of  the  newer  aluminum-copper  alloys, — capable  of 
better  resisting  weak  acid.  Before  the  cloth  is  printed  upon  it  passes  over 


494  BLEACHING,    DYEING,   AND   TEXTILE   FEINTING. 

a  "  lint  doctor,"  the  office  of  which  is  to  remove  any  loose  hair  or  fibres 
from  the  cloth.  Printing-machines  are  built  with  any  number  of  color 
boxes  and'  rollers  up  to  twelve  or  fourteen,  each  being  for  a  separate  color. 
Sansone  mentions  one  for  use  with  twenty  colors.  Great  nicety  is  required 
in  adjusting  the  machines  in  working  to  have  no  overlapping  of  colors  or 
mordants, — perfect  "  registration"  being  sought. 

For  drying  the  printed  goods  revolving  cylinders,  or  "  cans"  of  large 
diameter,  are  used,  or  the  goods  are  passed  over  heated  plates,  in  no  case 
allowing  the  printed  face  to  come  in  contact  with  any  part  of  the  apparatus. 
Steaming  follows  to  fix  the  colors.  The  apparatus  being  a  steamer,  as 
shown  on  p.  488,  or  one  constructed  of  brick  and  iron,  acting  continuously, 
thereby  turning  out  much  more  work  than  the  former.  The  dyeing-  and 
washing-machines  are  similar  to  those  already  described. 

Mordants,  Resists,  Discharges,  etc. — All  the  various  substances  used  in 
printing  must  be  applied  in  the  form  of  pastes,  the  consistency  of  which 
must  be  such  that  whenever  applied  they  will  not  run  or  spread,  which  impairs 
the  sharpness  of  outline  of  the  printed  pattern.  For  the  purpose  the  color- 
mixer  has  recourse  to  the  starches  and  gums,  the  most  important  of  which 
are  corn,  wheat  starch,  and  flour,  usually  made  up  into  ten  per  cent,  pastes. 
The  gums  include  gum  arable,  dextrine  (British  gum),  and  tragacanth.  The 
first  is  used  in  several  degrees  of  consistency,  from  a  fifty  to  a  one  hun- 
dred and  fifty  per  cent,  solution,  dextrine  the  same,  and  the  last  in  a 
ten  per  cent,  paste.  The  proportions  are  by  no  means  uniform,  but  they 
represent  the  average  strengths  used  in  the  color  house.  Blood  albumen  is 
considerably  used,  large  quantities  being  manufactured  cheaply  in  Chicago 
and  other  Western  localities.  The  mordants  used  embrace  the  acetates  of 
alumina  of  various  strengths,  basic  sulphate,  and  others  of  less  importance. 
The  acetates  and  nitrates  of  iron  are  the  most  prominent  salts  of  this  element, 
and  of  chromium  there  may  be  mentioned  the  acetates  and  nitrates ;  others, 
including  salts  of  tin,  calcium,  manganese,  are  also  used.  Owing  to  the 
great  number  of  recipes  published  for  preparing  mordants,  and  of  the  diffi- 
culty in  selecting  those  which  may  be  called  representative,  only  a  few  will 
be  given  of  the  more  important. 

Acetate  of  Alumina,  or  "  Red  Liquor"  (Crookes). — 

Water 45  gallons.  45  gallons. 

Alum 100  pounds.  200  pounds. 

Acetate  of  lead 100       "  200      " 

Soda  crystals 10       "  10       " 

Or  the  same  result  can  be  had  by  substituting  acetate  of  calcium  for  the 
lead  salt.  In  either  case  the  alumina  salt  is  dissolved  in  about  half  the 
quantity  of  water,  and  the  acetate  in  the  remainder,  when  the  two  solu- 
tions are  mixed  and  allowed  to  settle,  the  precipitated  lime  or  lead  sulphate 
being  removed.  The  addition  of  soda  is  to  neutralize  any  free  acetic  acid. 
Acetate  of  Iron,  or  "  Black  Iron  Liquor,"  can  be  obtained  either  by 
double  decomposition  as  above,  or  by  dissolving  scrap-iron  or  precipitated 
oxide  of  iron  in  crude  acetic  acid.  In  the  former  method  sulphate  of  iron 
and  acetate  of  lead  are  used  as  follows :  Water,  forty  pounds,  sulphate  of 
iron,  twenty-four  pounds,  acetate  of  lead,  twenty-four  pounds.  Dissolve 
each  separately,  mix,  and  filter.  The  oxide  of  iron  above  mentioned  is  ob- 
tained by  precipitating  a  solution  of  copperas  with  ammonia  or  soda,  filter- 
ing and  washing,  and  dissolving  the  moist  precipitate  in  ordinary  acetic 


TEXTILE   PRINTING.  495 

acid  to  make  a  twenty-five  per  cent,  solution.  In  the  event  of  using  soda, 
much  longer  washing  is  required. 

Nitrate  of  Iron  is  made  as  above ;  copperas  and  nitrate  of  lead  being 
used  for  the  decompositions  in  equal  proportions.  Nitrates  made  by  direct 
solution  are  obtained  by  several  methods,  the  best  being  nitric  acid  nearly 
saturated  with  scrap-iron  and  diluted  to  about  80°  Tw.  Some  of  the  so- 
called  nitrates  of  iron  are  mixtures  of  sulphate  and  nitrate  of  iron  and  some 
are  composed  entirely  of  sulphate  of  iron,  while  others  are  waste  liquors, 
such  as  are  obtained  by  dissolving  iron  out  of  "  tin  scrap"  by  means  of 
sulphuric  acid.  Others  may  contain  hydrochloric  acid,  with  or  without 
the  addition  of  copperas.  Chromium  Acetate  is  similarly  prepared  with 
chrome  alum  and  lead  acetate,  or  by  precipitating  chrome  alum  with  an 
alkali,  and  dissolving  the  washed  precipitate  in  acetic  acid,  or  in  nitric  acid 
if  the  nitrate  is  wanted.  This  latter  mordant  can  be  made  by  using  lead 
nitrate  and  chrome  alum. 

The  tin  mordants  are  used  to  brighten  the  color  with  madder  and  cochi- 
neal dyeing.  The  first  is  Stannous  Chloride,  SnCl2  +  2H2O.  It  is  made  by 
dissolving  tin  in  hydrochloric  acid  and  evaporating  the  solution.  It  is  used 
somewhat  in  wool-dyeing,  but  more  largely  in  calico-printing.  Stannic 
chloride,  SnCl4,  is  also  used,  and  its  combination  with  sal  ammoniac  known 
as  "  Pink  Salt,"  and  Sodium  Zincate,  Na^SnOg,  known  as  "  Preparing  Salt." 

The  principal  styles  of  printing  tissues  are  given  in  the  following 
scheme,  condensed  from  a  tabular  view  given  in  Sansone's  excellent  work 
on  "  Cotton-Printing." 

PRINTED  (DIRECT)  COLORS. 

1.  Steam  or  Extract  Styles. 

(a)  Coal-tar  Colors. 

Alizarin,  Basic  Aniline   Colors,  Acid   Colors,  and  Neutral 
Azo  Colors. 

(b)  Dyewood  Extracts  (natural  organic  coloring  matters). 

Logwood,   Quercitron  Bark,  Sapan  and  other  Red  Woods, 
Catechu,  Annatto,  Cochineal. 

(c)  Steam  Mineral  Colors. 

2.  Pigment  Styles  (fixed  by  albumen). 

3.  Oxidation  Colors. 

4.  Direct  Indigo-printing  ( alkaline  styles). 
DYED  COLORS. 

5.  Alizarin  Dyed  Styles. 

6.  Turkey-red  Styles. 

7.  Indigo  Styles. 

8.  Manganese  Bronze  Styles. 

1.  Steam  Styles. — Here  the  colors  and  proper  mordants  are  mixed,  and 
applied  to  the  fabric  in  one  operation,  followed  by  air  drying  and  steaming, 
or  by  immediate  steaming,  drying,  and  again  steaming,  the  object  in  each 
case  being  to  fix  and  develop  the  colors.  Several  conditions  are  to  be  noted 
in  this  style,  chiefly  the  humidity  of  the  steam,  temperature,  pressure,  and 
the  duration  of  the  steaming,  in  order  that  the  same  shades  may  be  again 
obtained  with  the  same  colors.  Before  being  printed  the  cloth  is  passed 
through  a  solution  of  stannate  of  soda,  also  called  "  preparing  salt,"  and 
then  through  sulphuric  acid  (1.005  to  1.015  specific  gravity),  washed,  and 
dried.  The  colors  best  suited  are  the  basic, — that  is,  those  which  form  in- 
soluble lakes  with  tannin  in  combination  with  a  metal,  and  the  general 


496  BLEACHING,   DYEING,   AND   TEXTILE   PRINTING. 

method  of  applying  the  same  is  given  in  the  following  extract  from  San- 
sone  ("  Printing"),  p.  208  :  "  A  color  is  formed  consisting  of  thickening,  the 
solution  of  coloring  matter,  and  acetic  acid.  The  acetic  acid  is  added  in 
the  preparation  of  the  color  in  order  to  prevent  the  tannic  acid  from  com- 
bining with  the  dyestuff ;  in  other  words,  the  acetic  acid  keeps  both  the 
coloring  matter  and  the  tannin  in  solution  in  the  thickened  color,  and  pre- 
vents their  combining  with  each  other ;  but  when  the  color  is  printed  and 
the  cloth  is  dried  and  steamed,  the  acetic  acid  is  expelled,  and  the  coloring 
matter  and  the  tannin  then  go  into  combination  to  form  the  insoluble  col- 
ored lake.  This  lake,  however,  not  being  sufficiently  fast  to  stand  by  itself, 
a  metallic  mordant  is  necessary  to  give  additional  fastness  to  the  colors ;  for 
this  reason  the  cloth,  after  printing,  dyeing,  and  steaming,  is  passed  into  a 
solution  containing  tartar  emetic/7  The  antimony  of  which  at  once  unites 
with  the  "  tannate"  of  the  color  already  on  the  fabric,  thereby  producing  a 
more  insoluble  body.  The  steaming  operation  must  be  conducted  with 
such  a  volume  of  steam  that  the  acetic  acid  volatilized  can  be  carried  away, 
or  else  the  colors  may  be  injured.  Of  the  colors  employed  may  be  men- 
tioned the  Fuchsines,  Methyl  Violets  and  Greens,  Bismarck  Brown,  Naph- 
thylene  Blue,  etc. 

Alizarin,  without  exception,  is  the  most  important  coloring  matter  used 
in  cotton-printing,  for  which  purpose  the  goods  are  previously  treated  with 
alizarin  oil  and  dried.  With  alizarin  in  printing,  as  in  dyeing,  the  color 
obtained  depends  upon  the  selection  of  the  mordant,  which  can,  however, 
be  a  mixture  ;  for  reds,  alumina,  with  or  without  tin  ;  purples,  iron  ;  browns, 
with  either  ferricyanide  of  potassium  or  acetate  of  iron,  and  acetate  of 
alumina,  or  with  chromium  mordants.  When  the  fabrics  have  been  printed 
they  are  steamed  for  one  or  two  hours,  and  passed  through  a  heated  chalk- 
bath,  washed,  and  soaped.  The  following  indicate  the  methods  of  preparing 
several  colors : 

Red.     (Standard.) 

Alizarin  paste  (fifteen  per  cent.) 6    pounds. 

Starch  paste 2    gallons. 

Acetate  of  alumina  (11°  Be.) 1£  pints. 

Acetate  of  lime  (15°  Be.) 1    pint. 

Nitrate  of  alumina  (13°  Be.) £     " 

Purple.     (Standard.) 

Alizarin 2  pounds. 

Starch  paste • 1  gallon. 

Acetate  of  iron  (13°  Be.) 1  quart. 

Acetate  of  lime  (13°  Be.) 1  pint. 

Acetic  acid 1     u 

Brown.     (Standard.) 

Alizarin  (fifteen  per  cent.) 4  pounds. 

Starch  paste 1  gallon. 

Nitro-acetate  of  chromium  (25°  Be.) 3  pounds. 

Acetate  of  lime  (13°  Be.) J-  pound. 

Since  the  introduction  of  the  alizarin  greens  and  violets,  their  use  in  con- 
nection with  chromium  in  cotton-printing  has  been  most  rapid. 

Dye-woods,  with  the  exception  of  logwood,  have  been  nearly  superseded 
by  the  tar  colors.  The  method  of  applying  the  color  is  nearly  the  same  as 
for  other  steam  colors, — viz.,  print,  dry  in  the  air,  steam,  and  wash,  and  is 
made  up  with  chromium  as  the  mordant,  and  an  oxidizing  agent,  with  or 
without  the  presence  of  another  coloring  matter  to  modify  the  shade. 


TEXTILE  PRINTING.  497 

The  following  recipes  illustrate  the  color  as  made  for  blacks : 

Steam  Logwood  Black.     (Sansone.) 

Water 1      gallon. 

Acetic  acid  (6°  Tw.) 1 

Logwood  extract  (30°  Tw.) 1 

Quercitron  bark  extract  (30°  Tw.) 2      pounds. 

Starch 5 

Dextrine 2.5 

Olive  oil 5 

Chlorate  of  potash  or  soda 75  pound. 

Boll,  stir,  until  cold,  then  add 

Acetate  of  chromium  (20°  Tw.) 1      gallon. 

Steam  Logwood  Black.     (Sansone.) 

Starch 6      pounds. 

Flour 6  " 

Acetic  acid  (6°  Tw.) 2.5  gallons. 

Logwood  extract  (20°  Tw.) 3.5         " 

Acetate  of  iron  (15°  Tw.) 3.5         " 

Olive  oil 1.5  pounds. 

Of  the  other  natural  coloring  matters  there  may  be  mentioned  Cochineal, 
applied  with  tin  or  alumina  ;  Sapan,  in  the  same  manner,  and  Quercitron 
Barky  with  alumina  or  chromium.  Catechu,  much  used  for  browns,  may  be 
applied  with  acetate  of  chromium  or  with  logwood  and  fuchsine. 

The  Mineral  Colors  are  to  some  extent  made  use  of,  their  application 
depending  upon  the  principle  of  double  decomposition  upon  its  fibre  when 
subjected  to  steaming.  The  following  examples  will  make  the  principle 
clear :  Yellows  are  obtained  by  the  decomposition  of  nitrate  of  lead  and  a 
soluble  chromate,  the  insoluble  chromate  of  lead  ("chrome  yellow")  being 
formed.  For  Blues,  both  prussiates  of  potash  are  used.  Brown  is  obtained 
by  means  of  chloride  of  manganese  and  bichromate  of  potash. 

2.  Pigment  Styles. — For  this  style  effects  are  produced  by  means  of  in- 
soluble color  lakes  and  the  mineral  colors,  which  are  fixed  upon  the  cloth 
by  steaming,  the  action  of  which  coagulates  the  albumen  with  which  the 
colors  are  invariably  mixed  for  printing.     The  colors  are  generally  supplied 
to  the  color-mixer  in  a  dry  condition,  and  include  Ultramarine  of  various 
qualities,    Vermilion  (sulphide  of  mercury),  the   Chromates  of  Lead  and 
Barium,   Cadmium   Yellow  (cadmium  sulphide),   Chrome  Green  (oxide  of 
chromium),  the  Ochres,  yellow  and  red,  and  Lamp-black.     A  familiar  ex- 
ample of  this  style  is  seen  in  cheap  flags  and  decorative  muslins. 

3.  Oxidation  Colors. — The  most  important  of  this  class  is  Aniline  Black, 
and  will  be  briefly  outlined  as  follows :  Aniline  oil  is  made  into  a  paste 
with  a  chlorate  (soda  generally)  and  a  metallic  salt,  with  the  proper  amount 
of  starch  paste.     This  is  printed  upon  the  fabric,  "  aged"  for  forty-eight 
hours,  or  passed  through  a  "  steam  ager,"  then  passed  through  a  warm  bath  of 
bichromate  of  potash,  washed  well,  and  finally  worked  through  a  soap-bath. 
The  metallic  salt  mentioned  acts  as  a  carrier  of  oxygen,  and  for  the  purpose 
vanadate  of  ammonium,  sulphide  of  copper,  bichromate  of  potash,  etc.,  are 
used.    For  the  preparation  of  the  color  paste  the  following  methods  are  given  : 

1.  Water '. 1  gallon. 

Aniline  salt 2  pounds. 

Aniline  oil 2        " 

Starch 2        " 

Dextrine £  pound. 

The  paste  is  made  first  with  the  starch  and  dextrine,  then  the  aniline  is  added. 

32 


498  BLEACHING,   DYEING,  AND   TEXTILE   PRINTING. 

2.  Chlorate  of  soda  (8°  Be.) 1  gallon. 

Starch 2  pounds. 

Dextrine £  pound. 

Chloride  of  ammonium |       " 

These  are  made  separately,  but  when  wanted  are  mixed,  and  two  pounds  of 
sulphide  of  copper  paste  are  added,  and  the  whole  well  mixed  and  strained. 
(Crookes.) 

The  use  of  vanadium  is  shown  by  the  following  method  (Sansone, 
"  Printing,"  p.  275) : 

Water 1    gallon. 

Starch 1£  pounds. 

Dextrine f  " 

Boil,  cool  down  to  120°  F.,  then  add 

Aniline  oil 1£  " 

previously  neutralized  with 

Hydrochloric  acid  (32°  Tw.) 1£  " 

Stir  until  cold,  then  add  a  cold  solution  of 

Chlorate  of  soda f  pound. 

Boiling  water 1  " 

Before  printing  add  further 

Vanadium  solution £        " 

Print,  dry  not  too  hard,  age  two  days,  then  pass  through  two  per  cent,  solution  of  bichro- 
mate of  potash  at  160°  F.,  wash  and  soap. 

The  vanadium  solution  is  made  with  vanadate  of  ammonia,  hydrochloric 
acid,  glycerine,  and  water,  and  contains  about  .15  gramme  per  litre. 

Other  colors  are  produced  by  oxidation, — namely,  Brown  (with  phenylen 
diamine,  Sansone),  by  simply  printing  with  a  chlorate,  drying,  and  steaming, 
Yellow,  Grays,  Olives,  Blues,  etc.  To  obtain  white  patterns  on  goods 
printed  with  aniline  black,  a  "  resist"  or  "  reserve"  is  first  applied  of  the 
desired  pattern,  consisting  of  white  arsenic  as  the  base,  with  caustic  soda, 
and  the  proper  thickening.  For  discharging  the  aniline  black  after  it  is 
printed,  permanganate  of  potash  is  used ;  the  goods  are  afterwards  passed 
through  a  solution  of  oxalic  acid. 

4.  Indigo-printing. — Indigo  is  printed  upon  cotton  fabrics  in  two  ways, 
one  of  which  is  known  as  the  "  Glucose/7  and  the  other  the  "  Reduced 
Indigo"  Process.  The  former  is  carried  out  as  follows  :  Indigo  is  finely 
ground,  and  made  into  a  paste  with  water,  to  which  is  added  caustic  soda ; 
this  is  now  kept  in  a  closed  vessel  in  order  to  prevent  as  much  as  possible 
the  absorption  of  carbonic  oxide  from  the  atmosphere.  When  used  in 
printing,  it  is  thickened  with  dextrine  and  starch  ;  the  following  table  (from 
Sansone,  "  Cotton-Printing,"  p.  284)  showing  the  proportions  used  for 
several  shades : 

Dark  blue.  Medium  blue.  Light  blue. 

Light  calcined  starch 3    parts.  3    parts.  3    parts. 

Indian  corn  starch 1£      "  1£      "  1£      " 

Water 3|      «  3£      «  3|      " 

Caustic  soda  lye  (70°  Tw.) 16       "  28       "  40       " 

Indigo  paste 30       "  18       "  6       " 

The  cloth,  before  being  printed  upon,  is  worked  through  a  twenty-five 
per  cent,  solution  of  glucose  and  dried.  After  printing,  the  cloth  must  be 
again  dried  and  passed  through  an  atmosphere  of  wet  steam,  in  an  appa- 
ratus shown  in  Fig.  126,  to  effect  the  reduction  of  the  indigo  which  now 
takes  place.  The  cloth  is  now  washed  in  water,  being  repeatedly,  during 
the  washing,  exposed  to  the  air,  when  the  reduced  indigo  is  oxidized  and 
its  real  color  appears.  The  reason  for  rapidly  steaming  is  to  act  upon  the 


TEXTILE   PRINTING. 


499 


FIG.  126. 


caustic  alkali  while  it  is  still  in  that  state,  as  if  it  should  become  car- 
bonated through  delay  little  reduction  will  take  place.  This  method  is 
employed  in  printing  indigo  upon 
alizarin-dyed  goods  and  in  other 
combinations  with  resists,  etc. 

The  "Reduced  Indigo  Pro- 
cess" is  based  upon  the  fact  that 
indigo,  when  finely  ground  and 
mixed  with  lime  and  thiosul- 
phate  of  soda  in  suitable  thick- 
ening agents,  is  reduced  ;  if,  with 
this  reduced  indigo  paste,  pat- 
terns are  printed  upon  cotton 
fabrics,  and  then  exposed  to  the 
air,  the  indigo  is  oxidized  with  a 
regeneration  of  the  blue  color. 
The  pieces  are  then  washed  and 
dried. 

Instead   of  using   indigo   in 
printing,  one  of  the  newer  colors, 
Immedial  Slue,  is  now  very  extensively  used  and  printed  with  suitable 
mordants  directly  upon  the  goods. 

5.  Dyed  Alizarin. — This  process  differs  from  all  those  previously  men- 
tioned in  that  the  colors  are  produced  by  first  printing  upon  the  fabric  the 
thickened  mordants  suited  to  alizarin,  ageing,  during  which  the  mordants 
so  printed  are  decomposed  and  more  firmly  fixed  upon  the  cloth,  dunging, 
an  operation  which  removes  the  thickening  no  longer  needed,  followed  by 
a  washing,  and  then  dyeing  with  alizarin,  and,  finally,  brightening.  The- 
mordants  used  for  Reds  are  generally  made  with  acetate  of  alumina,  thick- 
ened with  starch  or  flour,  and  dextrine,  while  by  the  addition  of  tin  to  such 
a  mixture  blue  shades  will  be  obtained.  For  Purples  or  Violets,  acetate  of 
iron  is  used  diluted  with  paste,  if  used  strong,  blacks  can  be  produced. 
Browns  are  obtained  with  catechu  and  copper  acetates.  Mixtures  of  the 
acetates  of  iron  and  alumina  yield  varying  shades  of  Chocolate.  Follow- 
ing the  printing  operation,  the  fabric  is  allowed  to  dry,  when  it  is  aged  by 
being  caused  to  pass  through  the  continuous  steamer;  here  the  acetates 
are  decomposed,  basic  salts  remaining  fixed  upon  the  cloth.  Formerly 
the  operation  was  conducted  in  large  rooms,  and  often  required  a  week 
to  finish ;  now  long  chambers  provided  with  a  series  of  rollers,  and  with 
requisite  means  for  steam  control,  are  used ;  it  must  be  remarked  that  colors 
obtained  upon  cloth  rapidly  aged  do  not  compare  in  fastness  with  those  ob- 
tained upon  cloth  slowly  aged.  Dunging  is  merely  a  transmission  of  the 
aged  cloth  through  solutions  of  phosphate,  arseniate,  or  silicate  of  soda, 
these  chemicals  having  displaced  the  somewhat  offensive  cow-dung  in  the 
operations  of  precipitating  the  mordant  upon  the  fibre,  and  also  to  remove 
the  thickening  and  excess  of  mordant,  after  which  the  cloth  is  well  washed 
and  then  dyed.  The  dye-bath  is  made  up  with  alizarin,  alizarin  oil,  tannin, 
etc.,  in  a  similar  manner  to  that  described  under  Dyeing  (p.  487),  after  which 
the  cloth  washed,  worked  in  alizarin  oil,  dried,  and  steamed,  then  washed 
and  soaped.  In  case  reds  have  been  dyed,  and  it  is  desirable  to  reduce 
their  tone,  "  cutting"  is  resorted  to  after  the  soaping,  by  means  of  a  solution 
of  stannic  chloride. 


500  BLEACHING,   DYEING,   AND   TEXTILE   PRINTING. 

Resists  are  substances  printed  upon  the  fabric  which  will  prevent  the  fix- 
ation of  color  at  those  places,  and  are  of  two  kinds,  chemical  and  mechanical ; 
the  former  are  composed  chiefly  of  citric  acid,  while  the  latter  are  made  up  of 
some  inert  substances,  such  as  pipe-clay,  beeswax,  etc.  Thus  a  resist  (or 
reserve)  of  citrate  of  soda  (lime-juice  and  soda  lye)  when  applied  to  the 
cloth  prevents  the  fixation  of  the  oxides  of  iron  or  alumina  on  the  fibre, 
and  therefore  when  the  cloth  is  afterwards  dunged  and  dyed  in  the  alizarin 
bath  the  reserved  spots  remain  white,  while  the  colors  will  be  formed  where 
the  mordant  has  been  fixed.  In  this  way  not  only  reds  and  pinks  can 
be  reserved,  but  purples,  chocolates,  and  blacks  also.  Discharges  are 
substances  printed  upon  goods  the  whole  of  which  had  been  mordanted, 
the  object  being  to  remove  the  mordant  from  places  where  whites  are  to 
appear,  consequently  when  the  piece  is  dyed  only  where  the  mordant  is 
intact  will  the  cloth  be  colored  ;  these  discharges  are  made  principally  with 
citric,  tartaric,  or  acetic  acid.  This  acid-containing  discharge  having  been 
printed  on,  the  goods  are  then  taken  through  a  solution  of  bleaching-powder 
(chloride  of  lime).  The  result  is  that  when  the  acids  have  been  printed 
on  chlorine  gas  is  liberated,  which  destroys  the  dye-color,  leaving  in  the 
simplest  cases  a  white  design  upon  a  colored  ground. 

6.  Turkey-red  Styles. — This  process  is  simply  printing  upon  cloth  which 
has  previously  been  dyed  Turkey-red  (see  p.  487)  by  means  of  discharges, 
which  may  or  may  not  be  made  so  as  to  yield  colored  patterns.     The  base 
is  citric  or  tartaric  acid,  thickened  with  a  suitable  paste,  and  if  for  colors, 
containing  a  salt  of  lead,  if  for  a  yellow  discharge,  or  ferro-prussiate  of 
potash,  for  a  blue  discharge,  or  iron  and  logwood,  for  a  black  discharge. 
After  printing  on  the  discharges,  the  goods  are  passed  through  a  bath  of 
bleaching-powder,  well  washed,  and  then,  if   lead   has   been  printed  on, 
passed  through  a  bath  of  bichromate  of  potash,  when  chrome  yellow  will 
be  produced.     If  the  prussiate  of  potash  has  been  printed,  a  blue  color 
will  be  developed.     Green  is  obtained  by  mixing  both  discharges  first. 

7.  Indigo  Styles  are  similar  to  the  above ;    resists  are  printed  on  the 
cloth,  which  is  then  dyed  in  the  vat  in  the  ordinary  manner,  when,  upon  a 
removal  of  the  resist  by  suitable  means,  white  patterns  are  had  upon  a  blue 
ground.     By  the  system  of  discharges  various  colors  may  be  put  on  by 
means  of  lead  and  other  metallic  salts.     Vermilion  is  applied  directly  with 
albumen.      For  a  discharge  which  has  to  be  afterwards  dyed  red  with 
alizarin,  bromide  of  manganese  and  an  aluminum  salt  are  used. 

8.  Manganese  Bronze  Style,  or  Bistre  Style. — This  process  has  for  its  ob- 
ject the  production  of  hydrated  peroxide  of  manganese  upon  the  fibre,  and 
the  subsequent  printing  of  colors  by  means  of  discharges.     The  goods  are 
worked  in  a  solution  of  manganous  chloride,  dried,  and  worked  in  soda  lye, 
washed,  and  passed  through  a  solution  of  chloride  of  lime  until  a  brown 
color  is  produced.     Wash,  dry,  and  the  goods  are  ready  for  printing.     A 
discharge  for  white  is  made  with  muriate  of  tin  (120°  Tw.) ;  for  blue,  yellow 
prussiate  of  potash  with  an  organic  acid ;  for  yellow,  a  lead  salt,  developed 
with  bichromate  of  potash.     Green  and  black  as  in  the  previous  style. 

Woollen-  and  Silk-printing. —  Wool,  either  as  yarn  or  fabric,  is  generally 
printed  with  the  tar  colors,  and  according  to  the  steam  style  previously  de- 
scribed. The  goods  are  dried  after  printing,  steamed  for  one  hour,  and 
well  washed.  Silk  is  printed  in  the  same  style  after  being  prepared  by 
suitable  agents,  such  as  tin  with  or  without  an  acid.  Previous  to  being 
printed  both  silk  and  wool  must  be  entirely  free  from  grease. 


TEXTILE   PRINTING. 


501 


The  following  table  from  Rupe's  "  Chemie  der  Natiirlichen  Farbstoffe" 
(Braunschweig,  1900)  shows  the  artificial  dye-colors  which  have  replaced 
or  are  in  practical  use  competing  with  the  natural  dyestuffs  named  : 


NATURAL  DYESTUFFS. 


Is  displaced  for  cotton. 


Is  displaced  for  wocl  and  silk. 


QUERCITRON  .... 


PERSIAN  BERRIES  . 


WELD 


FUSTIC 


LOGWOOD 


BRAZIL-WOOD 


COCHINEAL 


ARCHIL 


ANNATTO 


Mainly  by  substantive  dye-colors: 
Diamine  fast  yellow  B  A  (C. ) ,  Chlora- 
mine  yellow  (C.),  Chrysophenine  (C.), 
Aura-mine  (H.  G.),  Diamine  yellow 
(H.),  Chrysamine  (H.),  Thioflavine 
(G.).  For  printing  along  with  log- 
wood it  is  still  used  as  before. 

Are  still  much  used  in  cotton-print- 
ing and  in  connection  with  tin 
salts.  For  direct  printing  compete : 
Auramine,  Thioflavine  T  (C.),  the 
latter  exclusively  for  discharges; 
in  addition,  Chrysophenine  (H.), 
Chloramine  yettow  (H.),  Oriol  (G.). 
Important  are  also  the  yellow  sal- 
icylic acid  azo  colors,  such  as 
Alizarin  yellow  (H.),  etc. 

Is  hardly  ever  used  for  cotton. 


Almost  entirely  displaced  by  the  sub- 
stantive yellow  dyes,  as  with  quer- 
citron. In  addition,  Sun  yellow  (G. ), 
Diphenyl  fast  yellow  (G.),  Cresotin 
yellow  (G.),  also  by  Alizarin  yettow 
and  its  homologues  (H.).  For  print- 
ing in  connection  with  logwood  it 
is  still  unreplaced. 

In  cotton  dyeing  (for  black)  is  about 
given  up.  For  better  goods  is  re- 
placed by  Aniline  black,  Diaminogen 
black  (C.),  for  cheaper  goods  by 
the  direct  dyeing  and  diazotizable 
blacks:  Diamine  black  (C.),  Oxydia- 
mine  black  (C.),  Columbia  black  (C.), 
Direct  deep  black  (C.),  also  by  Vidal 
black,  Immedial  black  (G.  H.),  and 
similar  sulphated  products. 


For  cotton  scarcely  used  now,  being 
replaced  by  the  substantive  dye- 
ing reds :  Diamine  fast  red  F  (C.), 
Congorubine  (C.),  Diamine  bordeaux 
(C.),  Benzopurpurine  (G.  H.),  Dia- 
mine red  (H.),  also  by  Fuchsine 
(G.  H.),  Hessian  purple  (G.),  Safra- 
mine,  (H.),  Paranitraniline  red  (H.), 
Alizarin  red  (H.). 


For  cotton  is  replaced  by  the  dif- 
ferent artificial  orange  colors,  as 
Chrysophenine  (H.),  Chrysamine 
(H.) ,  Mikado  yellow  and  orange  (H. ). 


Is  not  much  used  now,  the  dif- 
ferent mordant  coloring  yellows 
having  taken  its  place.  In  ad- 
dition, Naphthol  yellow  S  (H.), 
Tartrazine,  Quinoline  yettow  (H.). 


Little  used  for  wool,  For  silk  re- 
placed by  Tartrazine,  Putting  yel- 
low (C.),  Naphthol  yellow  S  (H.). 


Is  little  used  for  wool,  but,  on  the 
other  hand,  largely  for  silk.  Is 
replaced  by  Naphthol  yellow  S, 
Fast  yellow  (C.),  Tartrazine,  Failing 
yellow  (C.),  Citronine(G.),  Jasmine 
(G.),  -420  yellow  (G.),  Alizarin  yel- 
low (H.). 

Is  still  much  used  in  wool-dyeing, 
although  strongly  pushed  by  the 
different  mordant-attracting  yel- 
lows :  Anthracene  yellow  C  (C.  G.), 
Chrome  yellow  (C.  G.),  Mordant  yel- 
low (C.  G.),  Fulling  yettow  (C.), 
.420  yettow  (H.),  Fast  yellow  (H.), 
Alizarin  yellow  (H.). 

With  wool  the  case  is  the  same  as 
with  cotton.  It  is  still  used  for 
dyeing,  but  is  losing  ground  rap- 
idly. The  substitutes  are  :  Naph- 
thol and  Naphthylamine  black  (C. 
G.  H.),  Brilliant  black  (C.  G.),  Dia- 
mond black  (C.G.  H.),  Wool  black 
(C.),  Alizarin  black  (G.  H.),  An- 
thracene black  (C.  G.),  Azo  acid 
black  (H.),  Chromotrope  S  (H.). 
For  silk,  still  used  enormously 
and  with  no  substitute. 

Also  for  wool  and  silk  almost  en- 
tirely replaced  by  Cloth  red  (C.), 
Wool  red(C.),  Acid  fuchsine  (G.), 
Fast  red  (H.),  Archil  substitute  (G.), 
Ponceau  (H.),  Apollo  red  (G.),  Ro- 
ceUin  (G.) ;  in  the  fulling  industry 
by  Alizarin  red  (C.  H.),  Diamine 
fast  red  (C.),  Chromotrope  (H.). 

Is  still  used  somewhat  for  wool  and 
silk,  but  is  being  displaced  by 
vivid  acid  wool  colors,  such  as 
Azoeosin  (G.),  Chromazon  red  (G.), 
Palatine  scarlet  (H.  C.),  Brilliant 
crocein  (H.),  Brilliant  cochineal 
(C.),  and  the  different  Ponceaux, 
etc. 

Has  practically  been  entirely  dis- 
placed for  wool  and  silk  by  the 
readily  levelling  red  acid  wool 
dyes:  Acid  fuchsine  (C.),  Azocar- 
mine  (C.  G.  H.),  Archil  substitute 
(C.  G.  H.),  Azofuchsine  (C.  G.  H.), 
Lanafuchsine  (C.),  Azorubine  (C.), 
Azo  acid  fuchsine  (H. ),  Rosindu- 
line  (G.I,  Apollo  red  (G.),  Chromo- 
trope (H.). 


502 


BLEACHING,   DYEING,   AND   TEXTILE   FEINTING. 


NATURAL  DYESTUFFS. 


Is  displaced  for  cotton. 


Is  displaced  for  wool  and  silk. 


SAFFLOWER 


BERBERINE 
CATECHU.  . 


INDIGO  .  . 


Was  first  replaced  for  cotton  by  the 
Eosines,  Phloxine  (C.  G.) ;  later 
these  were  displaced  by  Rhodamine 
(C.  G.),  Erica  (C.),  Diamine  rose 
(C.),  Geranine  (C.),  Safranine  (EL), 
etc. 


Still  used  for  cotton,  although  a 
whole  series  of  excellent  substan- 
tive dyes  have  appeared.  Espe- 
cially have  the  Diamine  colors, 
Benzo  and  Congo  colors  with  sup- 
plementary treatment  with  chrome 
and  copper,  recently  competed  suc- 
cessfully (C.),  and  Chrysoidine  (H.), 
Vesuvine  ( H. ) ,  etc.  For  calico-print- 
ing, catechu  is  still  very  largely 
used,  although  the  different  Aliza- 
rin colors  are  seeking  to  displace 
it  in  part  (C.). 

Despite  the  many  seriously  com- 
peting products  is  still  much  used 
for  cotton.  These  competing  prod- 
ucts are :  Synthetic  indigo,  Indoin 
(C.  G.  H.),  Naphthindon  (C.),  Fast 
cotton  blue  (C.),  Methylene  blue 
(C.  H.),  Indamine  blue  (H.),  Janus 
blue  (H.),  and  the  direct  coloring 
and  diazotizable  blues  of  the  Dia- 
mine, Diphenyl,  and  Benzo  color 
groups.  \Diamine  blue  and  related 
colors  (H.),  Diaminogen  blue  (C. 
H.).]  A  new  product,  Immedial 
blue  (C.  H.),  belonging  to  the  sul- 
phated  colors,  which  has  recently 
appeared,  seems  to  be  among  the 
most  important  substitutes.  In 
calico-printing,  Indigo  has  been  in 
part  replaced  by  the  Synthetic  in- 
digo preparations  and  by  the  dif- 
ferent basic  blues,  including  Nitroso 
blue,  Alizarin  blue,  etc.  (C.). 


Is  not  used  for  wool,  but  still  some- 
what for  silk.  Substitutes  are  the 
same  as  those  mentioned  for  Weld. 

Still  used  for  silk  in  combination 
with  logwood  in  large  amount 
without  any  competing  products 
(C.).  For  weighting  of  silk. 


On  wool,  is  replaced  on  the  one 
hand  by  Alizarin  blue  (C.  G.  H.), 
Synthetic  indigo,  Alizarin  cyanine 
(C.  G.  H.),  Anthracene  blue  (G.  H.), 
Chromotrope  F  B  (H.),  Gallamine 
blue  (G.),  Gallocyanine  (G.),  and 
on  the  other  hand  by  Sulpho- 
cyanine  (C.)  and  Lanacyl  blue. 
However,  the  application  of  In- 
digo to  wool  still  holds  out  rela- 
tively well. 


The  communications  upon  which  this  table  is  based  were  from  the  firms  of  Leopold  Casella  &  Co., 
of  Frankfurt-am-Main  (C.),  Joh.  Rud.  Geigy  &  Co.,  of  Basel  (G.),  and  Farbwerke,  vormals  Meister, 
Lucius  and  Bruning,  of  Hochst  (H.). 


1874.- 
1875.- 
1876.- 
1877.- 

1878.— 
1879.— 


1880. 
1881. 
1882. 


Bibliography. 

Die  Prufung  der  Zeugfarben,  W.  Stein. 

Hand-book  of  Dyeing  and  Calico-Printing,  W.  'Crookes,  London. 

Die  Colorie  der  Baumwolle,  C.  Romen,  Berlin. 

Manual  of  Dyeing  and  Dyeing  Receipts,  Napier,  London. 

Dyeing  and  Calico-Printing,  Grace  Calvert,  Manchester. 

Cantor  Lectures  on  Wool-Dyeing,  G.  Jarmain,  London. 

•Traite  de  la  Teinture  des  Soies,  M.  Moyret,  Lyons. 

Die  Seidenfarberei,  Werner  Schmid. 

Die  chemische  Bearbeitung  der  Schafwolle,  V.  Joclet,  Vienna. 

Le  Conditionnement  de  la  Soie,  Jules  Persoz,  Paris. 

Handbuch  der  Bleichkunst,  Victor  Joclet,  Vienna. 

Calico-Printing,  Bleaching,  and  Dyeing,  C.  O'Neill,  London. 

The  American  Dyer,  by  Gibson,  Boston. 

Die  Woll-  und  Seidendruckerei,  Victor  Joclet,  Vienna, 

Handbuch  der  Seidenfarberei,  Philip  David. 

Bleicherei,  Farberei  und  Appretur,  C.  Romen,  Berlin. 

A  System  of  Chemistry  applied  to  Dyeing,  Jas.  Napier,  Philadelphia. 

The  Art  of  Dyeing,  Cleaning,  and  Scouring,  Thos.  Love,  2d  ed.,  Philadelphia. 

Die  Technologic  der  Gespinnstfasern,  2  Bde.,  H.  Grothe,  Berlin. 

The  English  Dyer,  David  Smith,  Manchester. 

Die  Wascherei,  Bleicherei  und  Farberei  von  Wollengarnen,  R.  Sachse,  Leipzig. 

Manual  of  Colors  and  Dye-wares,  J.  W.  Slater,  London. 


BIBLIOGRAPHY.  503 

1882. — Dyeing  and  Tissue-Printing,  "W.  Crookes,  London. 

The  American  Practical  Dyer's  Companion,  J.  F.  Bird,  Philadelphia. 
1883. — La  Teinture  du  Coton,  A.  Kenard,  Paris. 

Traite  pratique  du  Degraissage,  etc.,  A.  Gillet,  Paris. 
1884. — Bleaching,  Dyeing,  and  Calico-Printing,  J.  Gardner,  London. 

Bleaching,  Dyeing,  and  Calico-Printing,  F.  J.  Bird,  London. 

Die  Bleicherei,  Druckerei,  Farberei,  etc.,  der  baumwollenen  Gewebe,  G.  Stein, 
Braunschweig. 

Dyer's  Practical  Guide,  F.  Sherry,  Franklin,  Massachusetts. 
1885. — Die  praktische  Anwendung  der  Theerfarben  in  der  Industrie,  E.  J.  Hodl,  Vienna. 

The  Dyeing  of  Textile  Fabrics,  J.  J.  Hummel,  London. 

Die  Beizen,  ihre  Darstellung,  etc.,  H.  Wolff,  Vienna. 

Die  Gesammte  Indigo-Kupenblau  Farberei,  etc.,  E.  Rudolf. 
1886. — Praktische  Anleitung  zur  Bleicherei,  etc.,  von  Jutestoffen,  R.  Ernst. 

Die  Appretur-Mittel  und  ihre  Anwendung,  F.  Polleyn,  Vienna. 
1887. — Teinture  et  Apprets  des  Tissus  de  Coton,  L.  Lefebre,  Paris. 

The  Printing  of  Cotton  Fabrics,  A.  Sansone,  Manchester. 

L'Art  de  la^Soie,  N.  Rondot,  2  vols.,  Paris. 
1888. — Dyeing,  A.  Sansone,  2  vols.,  Manchester. 

Praktische  Handbuch  der  Zeugdrucks,  E.  Lauber. 

Des  Couleurs  et  de  leurs  Applications,  2me  ed.,  E.  Chevreul,  Paris. 
1889. — Handbuch  der  Farberei,  Dr.  A.  Ganswindt,  Weimar. 

Les  Matieres  Colorantes  et  la  Chemie  de  la  Teinture,  C.  L.  Tassart,  Paris. 

The  Guide  for  Piece-Dyeing,  F.  W.  Reisig,  New  York. 
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Traite  de  Teinture  sur  Laine,  P.  F.  Levaux,  Liege. 

Ueber  das  Farbe  der  Strangseide,  W.  Vollbrecht,  Berlin. 

Bleicherei,  Wascherei,  Carbonisation,  J.  Herzfeld,  Berlin. 

Farberei  der  Baumwolle  mit  Substantiven  Farbstoffe,  Soxhlet,  Stuttgart. 

Anilin  Farberei  und  Druckerei  auf  Baumwolle,  Soxhlet,  Stuttgart. 
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Chemische  Technologie  der  Gespinnstfasern,  O.  Witt,  Berlin. 
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Silk-Dyeing,  Printing,  and  Finishing,  J.  H.  Hurst,  London. 

1893. — Traite  pratique  de  la  Teinture  et  de  V Impression,  2me  ed.,  M.  de  Vinant,  Paris. 
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Teinture  et  Impression,  Prud'homme,  Paris. 
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Les  Industries  Textiles,  Guignet,  Dommer,  et  Grandmougin,  Paris. 
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2te  Auf,,  Berlin, 


APPENDIX. 


I.    The  Metric  System. 

THE  French  metric  system  is  based  upon  the  idea  of  employing,  as  the 
unit  of  all  measures,  whether  of  length,  capacity,  or  weight,  a  uniform  un- 
changeable standard,  adopted  from  nature,  the  multiples  and  subdivisions 
of  which  should  follow  in  decimal  progression.  To  obtain  such  a  standard, 
the  length  of  one-fourth  part  of  the  terrestrial  meridian,  extending  from 
the  equator  to  the  pole,  was  ascertained.  The  ten-millionth  part  of  this  arc 
was  chosen  as  the  unit  of  measures  of  length,  and  was  denominated  metre. 
The  cube  of  the  tenth  part  of  the  metre  was  taken  as  the  unit  of  measures 
of  capacity,  and  denominated  litre.  The  weight  of  distilled  water,  at  its 
greatest  density,  which  this  cube  is  capable  of  containing,  was  called  kilo- 
gramme, of  which  the  thousandth  part  was  adopted  as  the  unit  of  weight, 
under  the  name  of  gramme.  The  multiples  of  these  measures,  proceeding  in 
a  decimal  progression,  are  distinguished  by  employing  the  prefixes,  deca, 
hecto,  kilo,  and  myria,  taken  from  the  Greek  numerals;  and  the  sub- 
divisions, following  the  same  order,  by  deti,  centi,  milli,  from  the  Latin 
numerals.  Since  the  introduction  of  this  system  it  has  been  adopted  by 
the  principal  nations  of  Europe,  excepting  Great  Britain,  and  in  many  of 
them  its  use  is  compulsory.  It  is  in  general  use  in  France,  Germany,  Aus- 
tria, Italy,  Spain,  Norway,  Sweden,  Netherlands,  Switzerland,  Greece,  and 
British  India.  It  was  legalized  in  Great  Britain  in  1864,  and  in  the  United 
States  by  an  act  of  Congress  in  1866. 

The  metre,  or  unit  of  length,  at  32°,   =     39.370432  inches. 

The  litre,  or  unit  of  capacity,  =     33.816  fluidounces.    U.  S. 

The  gramme,  or  unit  of  weight,  =     15.43234874  Troy  grains. 

Upon  this  basis  the  following  tables  have  been  constructed : 


MEASURES    OF    LENGTH. 


English  inches. 

Millimetre  (mm.)  =  .03937 

Centimetre  (cm.)  =  .39370 

Decimetre  (dm.)  =  3.93704 

Metre  (m.)  =  39.37043 


English  inches. 

Decametre  (Dm.)  =  393.70432 

Hectometre  (Hm.)          =  3937.04320 

Kilometre  (Km.)  ==          39370.43200 

Myriametre  (Mm.)         =        393704.32000 

505 


506 


Millilitre  (ml.) 
Centilitre  (cl.) 
Decilitre  (dl.) 
Litre  (1.) 


APPENDIX. 

MEASURES    OF   CAPACITY. 


English  cubic  inches. 

.061028 

.610280 

6.102800 

61.028000 


Decalitre  (Dl.) 
Hectolitre  (HI.) 
Kilolitre  (Kl.) 
Myrialitre  (Ml.) 


English  cubic  inches. 

610.280000 

6102.800000 

61028.000000 

610280.000000 


MEASURES   OF   WEIGHT. 


Milligramme  (mg.)  = 

Centigramme  (eg.)  = 

Decigramme  (ag.)  = 

Gramme  (gm.)  =• 


Troy  grains. 

.0154 

.1543 

1.5432 

15.4323 


Decagramme  (Dg.)  = 
Hectogramme  (Hg.)  = 
Kilogramme  (Kg.)  = 
Myriagramme  (Mg.)  = 


Troy  grains. 

154.3234 

1543.2348 

15432.3487 

154323.4874 


Value  of  Avoirdupois  Weights  and  Imperial  Measures,  in  Metric  Weights  and 
Measures,  as  stated  in  the  British  Pharmacopoeia. 


Avoirdupois  weights. 
1  pound  = 
1  ounce  = 
1  grain  = 


Metric  weights. 
453.5925  grammes. 
28.3495        " 
0.0648        " 


Imperial  measures. 

1  gallon 

1  pint 

1  fluidounce 

1  fluidrachm 

1  minim 


Metric  measures. 

4.543487  litres. 
0.567936     " 
0.028396     " 
0.003549     « 
0.000059     " 


Tables  for  Determination  of  Temperature. 


RELATIONS  BETWEEN  THERMOMETERS. 

In  Fahrenheit's  thermometer,  the  freezing-point  of  water  is  placed  at 
32°,  and  the  boiling-point  at  212°,  and  the  number  of  intervening  degrees 
is  180. 

The  Centigrade  or  Celsius's  thermometer,  which  is  now  recognized  in 
the  U.  S.  Pharmacopoaia  and  has  been  adopted  generally  by  scientists,  marks 
the  freezing-point  zero,  and  the  boiling-point  100°. 

From  the  above  statement,  it  is  evident  that  180  degrees  of  Fahrenheit 
are  equal  to  100°  of  the  Centigrade,  or  one  degree  of  the  first  is  equal  to 
f  of  a  degree  of  the  second.  It  is  easy,  therefore,  to  convert  the  degrees  of 
one  into  the  equivalent  number  of  degrees  of  the  other ;  but  in  ascertaining 
the  corresponding  points  upon  the  different  scales,  it  is  necessary  to  take  into 
consideration  their  different  modes  of  graduation.  Thus,  as  the  zero  of 
Fahrenheit  is  32°  below  the  point  at  which  that  of  the  Centigrade  is  placed, 
this  number  must  be  taken  into  account  in  the  calculation. 

1.  If  any  degree  on  the  Centigrade  scale,  either  above  or  below  zero,  be 
multiplied  by  1.8,  the  result  will,  in  either  case,  be  the  number  of  degrees 
above  or  below  32°,  or  the  freezing-point  of  Fahrenheit. 

2.  The  number  of  degrees  between  any  point  of  Fahrenheit's  scale  and 
32°,  if  divided  by  1.8,  will  give  the  corresponding  point  on  the  Centigrade. 


APPENDIX. 


507 


THERMOMETRIC  EQUIVALENTS. 

ACCORDING  TO  THE  CENTIGRADE  AND  FAHRENHEIT  SCALES. 


c.° 

F.° 

C.° 

F.° 

C° 

F.° 

C.° 

F.° 

O.° 

F°. 

—39.4 

—39 

—17.2 

1 

5 

41 

27.2 

81 

49.4 

121 

—39 

—38.2 

—17 

1.4 

5.5 

42 

27.7 

82 

50 

122 

—38.8 

—38 

—16.6 

2 

6 

42.8 

28 

82.4 

50.5 

123 

—38.3 

—37 

—16.1 

3 

6.1 

43 

28.3 

83 

51 

123.8 

-38 

—36.4 

—16 

3.2 

6.6 

44 

28.8 

84 

51.1 

124 

—37.7 

—36 

—15.5 

4 

7 

44.6 

29 

84.2 

51.6 

125 

—37.2 

—35 

—15 

5 

7.2 

45 

29.4 

85 

52 

125.6 

—37 

—34.6 

—14.4 

6 

7.7 

46 

30 

86 

52.2 

126 

—36.6 

—34 

—14 

6.8 

8 

46.4 

30.5 

87 

52.7 

127 

—36.1 

—33 

—13.8 

7 

8.3 

47 

31, 

87.8 

53 

127.4 

—36 

—32.8 

—13.3 

8 

8.8 

48 

31.1 

88 

53.3 

128 

—35.5 

—32 

—13 

8.6 

9. 

48.2 

31.6 

89 

53.8 

129 

—35 

—31 

—12.7 

9. 

9.4 

49 

32 

89.6 

54 

129.2 

—34.4 

-30 

—12.2 

10 

10 

50 

32.2 

90 

54.4 

130 

—34 

—29.2 

—12 

10.4 

10.5 

51 

32.7 

91 

55 

131 

—33.8 

—29 

—11.6 

11 

11 

51.8 

33 

91.4 

55.5 

132 

—33.3 

—28 

—11.1 

12 

11.1 

52 

33.3 

92 

56 

132.8 

—33 

—27.4 

—11 

12.2 

11.6 

53 

33.8 

93 

56.1 

133 

—32.7 

—27 

—10.5 

13 

12 

53.6 

34 

93.2 

56.6 

134 

—32.2 

—26 

—10 

14 

12.2 

54 

34.4 

94 

57 

134.6 

—32 

—25.6 

—9.4 

15 

12.7 

55 

35 

95 

57.2 

135 

—31.6 

—25 

—9 

15.8 

13 

55.4 

35.5 

96 

57.7 

136 

—31.1 

—24 

—8.8 

16 

13.3 

56 

36 

96.8 

58 

136.4 

—31 

—23.8 

—8.3 

17 

13.8 

57 

36.1 

97 

58.3 

137 

—30.5 

—23 

—8 

17.6 

14 

57.2 

36.6 

98 

58.8 

138 

—30 

—22 

—7.7 

18 

14.4 

58 

37 

98.6 

59 

138.2 

—29.4 

—21 

—7.2 

19 

15 

69 

37.2 

99 

59.4 

139 

—29 

—20.2 

—7 

19.4 

15.5 

60 

37.7 

100 

60 

140 

—28.8 

—20 

—6.6 

20 

16 

60.8 

38 

100.4 

60.5 

141 

—28.3 

—19 

—6.1 

21 

16.1 

61 

38.3 

101 

61 

141.8 

—28 

—18.4 

—6 

21.2 

16.6 

62 

38.8 

102 

61.1 

142 

—27.7 

—18 

—5.5 

22 

17 

62.6 

39 

102.2 

61.6 

143 

—27.2 

—17 

—5 

"23 

17.2 

63 

39.4 

103 

62 

143.6 

—27 

—16.6 

—4.4 

24 

17.7 

64 

40 

104 

62.2 

144 

—26.6 

—16 

—4 

24.8 

18 

64.4 

40.5 

105 

62.7 

145 

—26.1 

—15 

—3.8 

25 

18.3 

65 

41 

105.8 

63 

145.4 

—26 

—14.8 

—3.3 

26 

18.8 

66 

41.1 

106 

63.3 

146 

—25.5 

—14 

—3 

26.6 

19 

66.2 

41.6 

107 

63.8 

147 

—25 

—13 

—2.7 

27 

19.4 

67 

42 

107.6 

64 

147.2 

—24.4 

—12 

—2.2 

28 

20 

68 

42.2 

108 

64.4 

148 

—24 

—11.2 

—2 

28.4 

20.5 

69 

42.7 

109 

65 

149 

—23.8 

—11 

—1.6 

29 

21 

69.8 

43 

109.4 

65.5 

150 

—23.3 

—10 

—1.1 

30 

21.1 

70 

43.3 

110 

66 

150.8 

—23 

—9.4 

—1 

30.2 

21.6 

71 

43.8 

111 

66.1 

151 

—22.7 

—9 

—0.5 

31 

22 

71.6 

44 

111.2 

66.6 

152 

—22.2 

—8 

0 

32 

22.2 

72 

44.4 

112 

67 

152.6 

—22 

—7.6 

0.5 

33 

22.7 

73 

45 

113 

67.2 

153 

—21.6 

—7 

1 

33.8 

23 

73.4 

45.5 

114 

67.7 

154 

—21.1 

—6 

1.1 

34 

23.3 

74 

46 

114.8 

68 

154.4 

—21 

—5.8 

1.6 

35 

23.8 

75 

46.1 

115 

68.3 

155 

—20.5 

—5 

2 

35.6 

24 

75.2 

46.6 

116 

68.8 

156 

—20 

—4 

2.2 

36 

24.4 

76 

47 

116.6 

69 

156.2 

—19.4 

—3 

2.7 

37 

25 

77 

47.2 

117 

69.4 

157 

—19 

—2.2 

3 

37.4 

25.5 

78 

47.7 

118 

70 

158 

—18.8 

—2 

3.3 

38 

26 

78.8 

48 

118.4 

70.5 

159 

—18.3 

—1 

3.8 

39 

26.1 

79 

48.3 

119 

71 

159.8 

—18 

—0.4 

4. 

39.2 

26.6 

80 

48.8 

120 

71.1 

160 

—17.7 

0 

4.4 

40 

27 

80.6 

49 

120.2 

71.6 

161 

508 


APPENDIX. 
Thermometric  Equivalents. — Continued. 


c.° 

F.° 

C.° 

F.° 

C.° 

F.° 

C.° 

F.° 

C.° 

F.° 

72 

161.6 

95.5 

204 

118.8 

246 

142.2 

288 

166 

330.8 

72.2 

162 

96 

204.8 

119 

246.2 

142.7 

289 

166.1 

331 

72.7 

163 

96.1 

205 

119.4 

247 

143 

289.4 

166.6 

332 

73 

163.4 

96.6 

206 

120 

248 

143.3 

290 

167 

332.6 

73.3 

164 

97 

206.6 

120.5 

249 

143.8 

291 

167.2 

333 

73.8 

165 

97.2 

207 

121 

249.8 

144 

291.2 

167.7 

334 

74 

165.2 

97.7 

208 

121.1 

250 

144.4 

292 

168 

334.4 

74.4 

166 

98 

208.4 

121.6 

251 

145 

293 

168.3 

335 

75 

167 

98.3 

209 

122 

251.6 

145.5 

294 

168.8 

336 

75.5 

168 

98.8 

210 

122.2 

252 

146 

294.8 

169 

336.2 

76 

168.8 

99 

210.2 

122.7 

253 

146.1 

295 

169.4 

337 

76.1 

169 

99.4 

211 

123 

253.4 

i  146.6 

296 

170 

338 

76.6 

170 

100 

212 

123.3 

254 

147 

296.6 

170.5 

339 

77 

170.6 

100.5 

213 

123.8 

255 

147.2 

297 

171 

339.8 

77.2 

171 

101 

213.8 

124 

255.2 

147.7 

298 

171.1 

340 

77.7 

172 

101.1 

214 

124.4 

256 

148 

298.4 

171.6 

341 

78 

172.4 

101.6 

215 

125 

257 

148.3 

299 

172 

341.6 

78.3 

173 

102 

215.6 

125.5 

258 

148.8 

300 

172.2 

342 

78.8 

174 

102.2 

216 

126 

258.8 

149 

300.2 

172.7 

343 

79 

174.2 

102.7 

217 

126.1 

259 

149.4 

301 

173 

343.4 

79.4 

175 

103 

217.4 

126.6 

260 

150 

302 

173.3 

344 

80 

176 

103.3 

218 

127 

260.6 

150.5 

303 

173.8 

345 

80.5 

177 

103.8 

219 

127.2 

261 

151 

303.8 

174 

345.2 

81 

177.8 

104 

219.2 

127.7 

262 

151.1 

304 

174.4 

346 

81.1 

178 

104.4 

220 

128 

262.4 

151.6 

305 

175 

347 

81.6 

179 

105 

221 

128.3 

263 

152 

305.6 

175.5 

348 

82 

179.6 

105.5 

222 

128.8 

264 

152.2 

306 

176 

348.8 

82.2 

180 

106 

222.8 

129 

264.2 

152.7 

307 

176.1 

349 

82.7 

181 

106.1 

223 

129.4 

265 

153 

307.4 

176.6 

350 

83 

181.4 

106.6 

224 

130 

266 

153.3 

308 

177 

350.6 

83.3 

182 

107 

224.6 

130.5 

267 

153.8 

309 

177.2 

351 

83.8 

183 

107.2 

225 

131 

267.8 

154 

309.2 

177.7 

352 

84 

183.2 

107.7 

226 

131.1 

268 

154.4 

310 

178 

352.4 

84.4 

184 

108 

226.4 

131.6 

269 

155 

311 

178.3 

353 

85 

185 

108.3 

227 

132 

269.6 

155.5 

312 

178.8 

354 

85.5 

186 

108.8 

228 

132.2 

270 

156 

312.8 

179 

364.2 

86 

186.8 

109 

228.2 

132.7 

271 

156.1 

313 

179.4 

355 

86.1 

187 

109.4 

229 

133 

271.4 

156.6 

314 

180 

356 

86.6 

188 

110 

230 

133.3 

272 

157 

314.6 

180.5 

357 

87 

188.6 

110.5 

231 

133.8 

273 

157.2 

315 

181 

357.8 

87.2 

189 

111 

231.8 

134 

273.2 

157.7 

316 

181.1 

358 

87.7 

190 

111.1 

232 

134.4 

274 

158 

316.4 

181.6 

359 

88 

190.4 

111.6 

233 

135 

275 

158.3 

317 

182 

359.6 

88.3 

191 

112 

233.6 

135.5 

276 

158.8 

318 

182.2 

360 

88.8 

192 

112.2 

234 

136 

276.8 

159 

318.2 

182.7 

361 

89 

192.2 

112.7 

235 

136.1 

277 

159.4 

319 

183 

361.4 

89.4 

193 

113 

235.4 

136.6 

278 

160 

320 

183.3 

362 

90 

194 

113.3 

236 

137 

278.6 

160.5 

321 

183.8 

363 

90.5 

195 

113.8 

237 

137.2 

279 

161 

321.8 

184 

363.2 

91 

195.8 

114 

237.2 

137.7 

280 

161.1 

322 

184.4 

364 

91.1 

196 

114.4 

238 

138 

280.4 

161.6 

323 

185 

365 

91.6 

197 

115 

239 

138.3 

281 

162 

323.6 

185.5 

366 

92 

197.6 

115.5 

240 

138.8 

282 

162.2 

324 

186 

366.8 

92.2 

198 

116 

240.8 

139 

282.2 

162.7 

325 

186.1 

367 

92.7 

199 

116.1 

241 

139.4 

283 

163 

325.4 

186.6 

368 

93 

199.4 

116.6 

242 

140 

284 

163.3 

326 

187 

368.6 

93.3 

200 

117 

242.6 

140.5 

285 

163.8 

327 

187.2 

369 

93.8 

201 

117.2 

243 

141 

285.8 

164 

327.2 

187.7 

370 

94 

201.2 

117.7 

244 

141.1 

286 

164.4 

328 

188 

370.4 

94.4 

202 

118 

244.4 

141.6 

287 

165 

329 

188.3 

371 

95 

203 

118.3 

245 

142 

287.6 

165.5 

330 

188.8 

372 

APPENDIX. 

Tfiermometric  Equivalents. — Continued. 


509 


c.° 

F.° 

C.° 

F.° 

C.° 

F.° 

C.° 

F.° 

C.° 

F.° 

189 

372.2 

211.6 

413 

233.8 

453 

256.1 

493 

278.3 

533 

189.4 

373 

212 

413.6 

234 

453.2 

256.6 

494 

278.8 

534 

190 

374 

212.2 

414 

234.4 

454 

257 

494.6 

279 

534.2 

190.5 

375 

212.7 

415 

235 

455 

257.2 

495 

279.4 

535 

191 

375.8 

213 

415.4 

235.5 

456 

257.7 

496 

280 

536 

191.1 

376 

213.3 

416 

236 

456.8 

258 

496.4 

280.5 

537 

191.6 

377 

213.8 

417 

236.1 

457 

258.3 

497 

281 

537.8 

192 

377.6 

214 

417.2 

236.6 

458 

258.8 

498 

281.1 

538 

192.2 

378 

214.4 

418 

237 

458.6 

259 

498.2 

281.6 

539 

192.7 

379 

215 

419 

237.2 

459 

259.4 

499 

282 

539.6 

193 

379.4 

215.5 

420 

237.7 

460 

260 

500 

282.2 

540 

193.3 

380 

216 

420.8 

238 

460.4 

260.5 

501 

282.7 

541 

193.8 

381 

216.1 

421 

238.3 

461 

261 

501.8 

283 

541.4 

194 

381.2 

216.6 

422 

238.8 

462 

261.1 

502 

283.3 

542 

194.4 

382 

217 

422.6 

239 

462.2 

261.6 

503 

283.8 

543 

195 

383 

217.2 

423 

239.4 

463 

262 

503.6 

284 

5432 

195.5 

384 

217.7 

424 

240 

464 

262.2 

504 

284.4 

544 

196 

384.8 

218 

424.4 

240.5 

465 

262.7 

505 

285 

545 

196.1 

385 

218.3 

425 

241 

465.8 

263 

505.4 

285.5 

546 

196.6 

386 

218.8 

426 

241.1 

466 

263.3 

506 

286 

546.8 

197 

386.6 

219 

426.2 

241.6 

467 

263.8 

507 

286.1 

547 

197.2 

387 

219.4 

427 

242 

467.6 

264 

507.2 

286.6 

548 

197.7 

388 

220 

428 

242.2 

468 

264.4 

508 

287 

548.6 

198 

388.4 

220.5 

429 

242.7 

469 

265 

509 

287.2 

549 

198.3 

389 

221 

429.8 

243 

469.4 

265.5 

510 

287.7 

550 

198.8 

390 

221.1 

430 

243.3 

470 

266 

510.8 

288 

550.4 

199 

390.2 

221.6 

431 

243.8 

471 

266.1 

511 

288.3 

551 

199.4 

391 

222 

431.6 

244 

471.2 

266.6 

512 

288.8 

552 

200 

392 

222.2 

432 

2444 

472 

267 

512.6 

289 

552.2 

200.5 

393 

222.7 

433 

245 

473 

267.2 

513 

289.4 

553 

201 

393.8 

223 

433.4 

245.5 

474 

267.7 

514 

290 

554 

201.1 

394 

223.3 

434 

246 

474.8 

268 

514.4 

290.5 

555 

201.6 

395 

223.8 

435 

246.1 

475 

268.3 

515 

291 

555.8 

202 

395.6 

224 

435.2 

246.6 

476 

268.8 

516 

291.1 

556 

202.2 

396 

224.4 

436 

247 

476.6 

269 

516.2 

291.6 

557 

202.7 

397 

225 

437 

247.2 

477 

269.4 

517 

292 

557.6 

203 

397.4 

225.5 

438 

247.7 

478 

270 

518 

292.2 

558 

203.3 

398 

226 

438.8 

248 

478.4 

270.5 

519 

292.7 

559 

203.8 

399 

226.1 

439 

248.3 

479 

271 

519.8 

293 

559.4 

204 

399.2 

226.6 

440 

248.8 

480 

271.1 

520 

293.3 

560 

204.4 

400 

227 

440.6 

249 

480.2 

271.6 

521 

293.8 

561 

205 

401 

227.2 

441 

249.4 

481 

272 

521.6 

294 

561.2 

205.5 

402 

227.7 

442 

250 

482 

272.2 

522 

294.4 

562 

206 

402.8 

228 

442.4 

250.5 

483 

272.7 

523 

295 

563 

206.1 

403 

228.3 

443 

251 

483.8 

273 

523.4 

295.5 

564 

206.6 

404 

228.8 

444 

251.1 

484 

273.3 

524 

296 

564.8 

207 

404.6 

229 

444.2 

251.6 

485 

273.8 

525 

296.1 

565 

207.2 

405 

229.4 

445 

252 

485.6 

274 

525.2 

296.6 

566 

207.7 

406 

230 

446 

252.2 

486 

274.4 

526 

297 

566.6 

208 

406.4 

230.5 

447 

252.7 

487 

275 

527 

297.2 

567 

208.3 

407 

231 

447.8 

253 

487.4 

275.5 

528 

297.7 

568 

208.8 

408 

231.1 

448 

253.3 

488 

276 

528.8 

298 

568.4 

209 

408.2 

231.6 

449 

253.8 

489 

276.1 

529 

298.3 

569 

209.4 

409 

232 

449.6 

254 

489.2 

276.6 

530 

298.8 

570 

210 

410 

232.2 

450 

254.4 

490 

277 

530.6 

299 

570.2 

210.5 

411 

232.7 

451 

255 

491 

277.2 

531 

299.4 

571 

211 

411.8 

233 

451.4 

255.5 

492 

277.7 

532 

300 

572 

211.1 

412 

233.3 

452 

256 

492.8 

278 

532.4 

510 


APPENDIX. 


m.   Specific  Gravity  Tables. 
1.   Baum&s  Scale  for  Liquids  Lighter  than  Water. 

The  following  table  is  calculated  for  a  temperature  of  17.5°  C.  (63.5°  F.), 

and  is  based  on  the  formulas  =r-r — -  =  specific  gravity  and r 

B.  °  -f  1 30  specific  gravity 

— 130  — B.°. 


Degree 
Baum6. 

Specific 
gravity. 

Degree 
Baume. 

Specific 
gravity. 

Degree 
Baum6. 

Specific 
gravity. 

Degree 
Baum6. 

Specific 
gravity. 

10 

1.0000 

33 

0.8588 

56 

0.7526 

79 

0.6698 

11 

0.9929 

34 

0.8536 

57 

0.7486 

80 

0.6666 

12 

0.9859 

35 

0.8484 

58           0.7446 

81 

0.6635 

13 

0.9790 

36 

0.8433 

59 

0.7407 

82 

0.6604 

14 

0.9722 

37 

0.8383 

60 

0.7368 

83 

0.6573 

15 

0.9655 

38 

0.8333 

61 

0.7329 

84 

0.6542 

16 

0.9589 

39 

0.8284 

62           0  7290 

85 

0.6511 

17 

0.9523 

40 

0.8235 

63 

0.7253 

86 

0.6482 

18 

0.9459 

41 

0.8187 

64 

0.7216 

87 

0.6452 

19 

0.9395 

42 

0.8139 

65 

0.7179 

88 

0.6422 

20 

0.9333 

43 

0.8092 

66 

0.7142 

89 

0.6393 

21 

0.9271 

44 

0.8045 

67 

0.7106 

90 

0.6363 

22 

0.9210 

45 

0.8000 

68 

0.7070 

91 

0.6335 

23 

0.9150 

46 

0.7954 

69 

0.7035 

92 

0.6306 

24 

0.9090 

47 

0.7909 

70 

0.7000 

93 

0.6278 

25 

0.9032 

48 

0.7865 

71 

0.6965 

94 

0.6250 

26 

0.8974 

49 

0.7821 

72 

0.6931 

95 

0.6222 

27 

0.8917 

50 

0.7777 

73 

0.6896 

96 

0.6195 

28 

0.8860 

51 

0.7734 

74 

0.6863 

97 

0.6167 

29 

0.8805 

52 

0.7692 

75 

0.6829 

98 

0.6140 

30 

0.8750 

53 

0.7650 

76 

0.6796 

99 

0.6113 

31 

0.8695 

54 

0.7608 

77 

0.6763 

100 

0.6087 

32 

0.8641 

55 

0.7567 

78 

0.6731 

The  coefficient  of  expansion  of  petroleum  oils  for  increase  or  decrease  of 
1°  C.  in  temperature  has  been  determined  for  both  Russian  and  American 
oils.  For  the  latter  the  following  figures  have  been  given  (Iron  Age,  xxxviii. 
No.  7) : 

Specific  gravity  Coefficient  of 

at  15°  C.  (59°  F.).  expansion  for  1°  C. 

Under  0.700 0.00090 

0.700  to  0.750 0.00085 

0.750  to  0.800 0.00080 

0.800  to  0.815 0.00070 

Over  0.815  .  ....  0.00065 


As  stated  in  the  text  (p.  34),  it  is  customary  in  practice  to  take  as  the 
coefficient  of  expansion  0.004  for  every  10°  F.  (0.00072  for  1°  C.). 


APPENDIX. 


511 


2.  Baume  and  Beck's  Scales  for  Liquids  Heavier  than  Water. 


Degrees. 

Baume  , 
17.5°  C. 

Rational 
Baume 
scale, 
12.5°  C. 

Beck, 
12.5°  C. 

i 

BaumS, 
17.5°  C. 

Rational 
Baume 
scale, 
12.5°  C. 

Beck, 
12.5°  C. 

0 

1.0000 

Sp.  gr. 
1.0000 

Sp.  gr. 
1.0000 

37 

Sp.  gr. 
1.3370 

Sp.  gr. 
1.3447 

Sp.  gr. 

1.2782 

1 

1.0068 

1.0069 

1.0059 

38 

1.3494 

1.3574 

1.2879 

2 

.0138 

1.0140 

1.0119 

39 

.3619 

1.3703 

1.2977 

3 

.0208 

1.0212 

1.0180 

40 

.3746 

1.3834 

1.3077 

4 

.0280 

1.0285 

1.0241 

41 

.3876 

1.3968 

1.3178 

5 

.0353 

1.0358 

1.0303 

42 

.4009 

1.4105 

1.3281 

6 

.0426 

'  1.0434 

1.0366 

43 

.4143 

1.4244 

1.3386 

7 

.0501 

1.0509 

1.0429 

44 

.4281 

1.4386 

1.3492 

8 

.0576 

1.0587 

1.0494 

45 

.4421 

1.4531 

1.3600 

9 

.0653 

1.0665 

1.0559 

46 

1.4564 

1.4678 

1.3710 

10 

.0731 

1.0745 

1.0625 

47 

1.4710 

1.4828 

1.3821 

11 

.0810 

1.0825 

1.0692 

48 

1.4860 

1.4984 

1.3934 

12 

.0890 

1.0907 

1  0759 

49 

1.5012 

1.5141 

1.4050 

13 

.0972 

1.0990 

1.0828 

50 

1.5167 

1.5301 

1.3167 

14 

.1054 

1.1074 

1.0^97 

51 

1  5325 

1.5466 

1.4286 

15 

.1138 

1.1160 

1.0968 

52 

1.5487 

1.5633 

1.4407 

16 

.1224 

1.1247 

1.1031 

63 

1.5652 

1.5804 

1.4530 

17 

1.1310 

1.1335 

1.1119 

54 

1.5820 

1.5978 

1.4655 

18 

1.1398 

1.1425 

1.1184 

55 

1.5993 

1.6158 

1.4783 

19 

1.1487 

1.1516 

1.1258 

56 

1.6169 

1.6342 

1.4912 

20 

.1578 

1.1608 

1.1333 

57 

1.6349 

1.6529 

1.5044 

21 

.1670 

1.1702 

1.1409 

58 

1.6533 

1.6720 

1.5179 

22 

.1763 

1.1798 

1.1486 

59 

1.6721  ' 

1.6916 

1.5315 

23 

.1858 

1.1896 

1.1565 

60 

1.6914 

1.7116 

1  5434 

24 

.1955 

1.1994 

1.1644 

61 

1.7111 

1.7322 

1.5596 

25 

.2053 

1.2095 

1.1724 

62 

1.7313 

1.7532 

1.5741 

26 

.2153 

1.2198 

1.1806 

63 

1.7520 

1.7748 

1.5888 

27 

.2254 

1.2301 

1.1888 

64 

1.7731 

1.7960 

1.6038 

28 

.2357 

1.2407 

1.1972 

65 

1.7948 

1.8195 

1.6190 

29 

1.2462 

1.2515 

1.2057 

66 

1.8171 

1.8428 

1.6346 

30 

1.2569 

1.2624 

1.2143 

67 

1.8398 

1.839 

1.6505 

31 

1.2677 

1.2736 

1.2230 

68 

1.8632 

1.864 

1.6667 

32 

1.2788 

1.2849 

1  2319 

69 

1.8871 

1.885 

1.6832 

33 

1.2901 

1.2965 

1.2409 

70 

1.9117 

1.909 

1.7000 

34 

1.3015 

1.3082 

1.2500 

71 

1.9370 

1.935 

1.7272 

35 

1.3131 

1.3202 

1.2593 

72 

1.9629 

1.960 

1.7347 

36 

1.3250 

1.3324 

1.2687 

What  is  known  as  the  "  Rational"  Banine"  scale  is  calculated  by  taking 
water  at  the  temperature  chosen  at  0°  B.  and  sulphuric  acid  of  1.84' 

144.3 


specific  gravity  at  66°  B.  and  using  the  formula 
Lunge's  "  Sulphuric  Acid  and  Alkali,"  vol.  i.  p.  20.) 


144.3  _ 


=  d.    (See 


512 


APPENDIX. 


3.  Twaddle's  Scale  for  Liquids  Heavier  than  Water. 


Degrees 
Twaddle. 

«§£ 

'5  > 

S.2 

£*> 

Degrees 
Twaddle.  | 

££• 
li 
£* 

I  Degrees 
|  Twaddle. 

££ 

'5  > 

£2 

C&  60 

Degrees 
Twaddle. 

££ 

'G  > 

ii 

Degrees 
Twaddle. 

££ 
t> 
.6 

Degrees 
Twaddle. 

0  >• 

H 

Degrees 
Twaddle. 

«£ 

1| 

cc  ** 

0 

.000 

29 

.145 

58 

.290 

87 

.435 

116 

1.580 

145 

1.725 

173 

1.865 

1 

.005 

30 

.150 

59 

.295 

88 

.440 

117 

.585 

146 

1.730 

174 

1.870 

2 

.010 

31 

.155 

60 

.300 

89 

.445 

118 

.590 

147 

1.735 

175 

1.875 

3 

.015 

32 

.160 

61 

.305 

90 

.450 

119 

.595 

148 

1.740 

176 

1.880 

4 

.020 

33 

.165 

62 

.310 

91 

.455 

120 

.600 

149 

1.745 

177 

1.885 

5 

.025 

34 

.170 

63 

.315 

92 

.460 

121 

.605 

150 

1.750 

178 

1.890 

6 

.030 

35 

.175 

64 

.320 

93 

1.465 

122 

.610 

151 

1.755 

179 

1.895 

7 

.035 

36 

.180 

65 

.325 

94 

1.470 

123 

.615 

152 

1.760 

180 

1.900 

8 

1.040 

37 

.185 

66 

.330 

95 

1.475 

124 

.620 

153 

1.765 

181 

1.905 

9 

1045 

38 

.190 

67 

.335 

96 

1.480 

125 

625 

154 

1.770 

182 

1.910 

10 

1.050 

39 

.195 

68 

.340 

97 

1.485 

126 

1.630 

155 

1.775 

i  183 

1.915 

11 

.055 

40 

.200 

69 

.345 

98 

1.490 

127 

1.635 

156 

1.780 

184 

1.920 

12 

.060 

41 

.205 

70 

.350 

99 

1.495 

128 

1.640 

157 

1.785 

185 

1.925 

13 

.065 

42 

.210 

71 

.355 

100 

1.500 

129 

1.645 

158 

1.790 

186 

1.930 

14 

.070 

43 

.215 

72 

.360 

101 

1.505 

130 

1.650 

159 

.795 

i  187 

1.935 

15 

.075 

44 

.220 

73 

.365 

102 

1.510 

131 

1.655 

160 

.800 

188 

1.940 

16 

.080 

45 

.225 

74 

.370 

103 

1.515 

132 

1.660 

161 

.805 

189 

1.945 

17 

.085 

46 

.230 

75 

.375 

104 

1.520 

133 

1.665 

162 

.810 

190 

1.950 

18 

.090 

47 

.235 

76 

.380 

105 

1.525 

134 

1.670 

163 

.815 

191 

1.955 

19 

.095 

48 

.240 

77 

.385 

106 

1.530 

135 

1.675 

164 

.820 

192 

1.960 

20 

.100 

49 

.245 

78 

.390 

107 

1.535 

136 

1.680 

165 

.825 

193 

1.965 

21 

.105 

50 

.250 

79 

.395 

108 

1.540 

137 

1.685 

!  166 

1.830 

194 

1.970 

22 

.110 

51 

.255 

80 

.400 

109 

1.545 

138 

1.690 

j  167 

1.835 

195 

1.975 

23 

.115 

52 

.260 

81 

.405 

110 

1.550 

139 

1.695 

168 

1.840 

196 

1.980 

24 

.120 

53 

.265 

82 

.410 

111 

1.555 

140 

1.700 

169 

1.845 

197 

1.985 

25 

.125 

54 

.270 

83 

.415 

112 

1.560 

141 

1.705 

170 

1.850 

198 

1.990 

26 

.130 

55 

.275 

84 

.420 

113 

1.565 

142 

1.710 

171 

1.855 

199 

1.995 

27 

.135 

56 

.280 

85 

.425 

114 

1.570 

143 

1.715 

172 

1.860 

200 

2.000 

28 

.140 

57 

.285 

86 

.430 

115 

1.575 

144 

1.720 

The  uniform  division  of  the  Twaddle  scale  makes  the  degrees  very 
easily  convertible  into  specific  gravity  readings.  It  is  only  necessary  to 
multiply  the  degree  as  read  oif  by  five  and  add  this  to  1.000  in  order  to 
obtain  the  specific  gravity. 

Again,  as  the  gallon  of  distilled  water  at  ordinary  temperatures  weighs 
ten  pounds  avoirdupois,  it  is  possible  to  determine  the  weight  of  a  gallon 
of  an  acid  or  lye  by  the  aid  of  the  Twaddle  scale.  Thus,  if  an  acid  shows 
50°  Twaddle,  corresponding  to  the  specific  gravity  1.250,  it  weighs  twelve 
and  a  half  pounds  per  gallons.  Or,  as  a  litre  of  distilled  water  weighs  one 
thousand  grammes,  a  litre  of  a  liquid  showing  20°  Twaddle  will  weigh 
eleven  hundred  grammes. 


APPENDIX. 


513 


4.   Comparison  of  the  Twaddle  Scale  with  the  Rational  Baume  Scale. 


Twaddle. 

1 

Specilic 
gravity. 

Twaddle. 

1 

«£• 

fi 

5.M 
00 

Twaddle. 

1 

fi 

• 

Twaddle.  • 

1 

it 
Sg 
£*> 

0 

0 

.000 

44 

26.0 

1.220 

88 

44.1 

1.440 

131 

57.1 

1.655 

1 

0.7 

.005 

45 

264 

1.225 

89 

44.4 

1.445 

132 

57.4 

1.660 

2 

1.4 

.010 

46 

26.9 

1.230 

90 

44.8 

1.450 

133 

57.7 

1.665 

3 

2.1 

.015 

47 

27.4 

1.235 

91 

45.1 

1.455 

134 

57.9 

1.670 

4 

2.7 

.020 

48 

27.9 

1.240 

92 

45.4 

1.460 

135 

58.2 

1.675 

5 

3.4 

.025 

49 

28.4 

1.245 

93 

45.8 

1.465 

136 

58.4 

1.680 

6 

4.1 

.030 

50 

28.8 

1.250 

94 

46.1 

1.470 

137 

58.7 

1.685 

7 

4.7 

.035 

51 

29.3 

1.255 

95 

46.4 

1.475 

138 

58.9 

1.690 

8 

5.4 

.040 

52 

29.7 

1.260 

96 

46.8 

1.480 

139 

59.2 

1.695 

9 

6.0 

.045 

53 

30.2 

1.265 

97 

47.1 

1.485 

140 

59.5 

1.700 

10 

6.7 

.050 

54 

30.6 

1.270 

98 

47.4 

1.490 

141 

59.7 

1.705 

11 

7.4 

.055 

55 

31.1 

1.275 

99 

47.8 

1.495 

142 

60.0 

1.710 

12 

8.0 

.060 

56 

31.5 

1.280 

100 

48.1 

1.500 

143 

60.2 

1.715 

13 

8.7 

.065 

57 

32.0 

1.285 

101 

48.4 

1.505 

144 

60.4 

1.720 

14 

9.4 

.070 

58 

32.4 

1.290 

102 

48.7 

1.510 

145 

606 

1.725 

15 

10.0 

.075 

59 

32.8 

1.295 

103 

49.0 

1.515 

146 

60.9 

.730 

16 

10.6 

.080 

60 

33.3 

1.300 

104 

49.4 

1.520 

147 

61.1 

.735 

17 

11.2 

.085 

61 

33.7 

1.305 

105 

49.7 

1.525 

148 

61.4 

.740 

18 

11.9 

.090 

62 

34.2 

1.310 

106 

50.0 

1.530 

149 

61.6 

.745 

19 

12.4 

.095 

63 

34.6 

1.315 

107 

50.3 

1.535 

150 

61  8 

.750 

20 

13.0 

.100 

64 

35.0 

1.320 

108 

50.6 

1.540 

151 

62.1 

755 

21 

13.6 

.105 

65 

35.4 

1.325 

109 

50.9 

1.545 

152 

62.3 

.760 

22 

14.2 

.110 

66 

35.8 

1.330 

110 

51.2 

1.550 

153 

62.5 

.765 

23 

14.9 

.115 

67 

36.2 

1.335 

111 

51.5 

1.555 

154 

62.8 

.770 

24 

15.4 

.120 

68 

36.6 

1.340 

112 

51.8 

1.560 

155 

63.0 

.775 

25 

16.0 

.125 

69 

37.0 

1.345 

113 

52.1 

.565 

156 

63.2 

1.780 

26 

16.5 

1.130 

70 

37.4 

1350 

114 

52.4 

.570 

157 

63.5 

1.785 

27 

17.1 

1.135 

71 

37.8 

1.355 

115 

52.7 

.575 

158 

63.7 

1.790 

28 

17.7 

1.140 

72 

38.2 

1.360 

116 

53.0 

.580 

159 

64.0 

1.795 

29 

18.3 

1.145 

73 

38.6 

1.365 

117 

53.3 

.585 

160 

64.2 

1.800 

30 

18.8 

1.150 

74 

39.0 

1.370 

118 

53.6 

.590 

161 

64.4 

1.805 

31 

19.3 

1.155 

75 

39.4 

1.375 

119 

53.9 

.595 

162 

64.6 

1.810 

32 

19.8 

1.160 

76 

39.8 

1.380 

120 

54.1 

.600 

163 

64.8 

1.815 

33 

20.3 

.165 

77 

40.1 

1.385 

121 

54.4 

.605 

164 

65.0 

1.820 

34 

20.9 

.170 

78 

40.5 

1.390 

122 

54.7 

.610 

165 

65.2 

1.825 

35 

21.4 

.175 

79 

40.8 

1.395 

123 

55.0 

1.615 

166 

65.5 

1.830 

36 

22.0 

.180 

80 

41.2 

1.400 

124 

55.2 

1.620 

167 

65.7 

1.835 

37 

22.5 

.185 

81 

41.6 

1.405 

125 

55.5 

1.625 

168 

65.9 

1.840 

38 

23.0 

.190 

82 

42.0 

1.410 

126 

55.8 

1.630 

169 

66.1 

1.845 

39 

23.5 

.195 

83 

42.3 

1.415 

127 

56.0 

1.635 

170 

66.3 

1.850 

40 

24.0 

.200 

84 

42.7 

1.420 

128 

56.3 

1.640 

171 

66.5 

1.855 

41 

24.5 

.205 

85 

43.1 

1.425 

129 

56.6 

1.645 

172 

66.7 

1.860 

42 

25.0 

.210 

86 

43.4 

1.430 

130 

56.9 

1.650 

173 

67.0 

1.865 

43 

25.5 

.215 

87 

43.8 

1.435 

33 


514 


APPENDIX. 


5.   Comparison  of  Gay-Lussac  Scale  with  Absolute  Specific  Gravity  Figures. 


Degree. 

Specific 
gravity, 
Gay-Lussac. 

Degree. 

Specific 
gravity, 
Gay-Lussac. 

Degree. 

Specific 
gravity, 
Gay-Lussac. 

Degree. 

Specific 
gravity, 
Gay-Lussac. 

50 

2.0000 

76 

1.3158 

102 

0.9804 

127 

0.7874 

51 

.9608 

77 

1.2987 

103 

0.9709 

128 

0.7813 

52 

.9231 

78 

1.2821 

104 

0.9615 

129 

0.7752 

53 

.8868 

79 

1.2658 

105 

0.9524 

130 

0.7692 

54 

.8519 

80 

1.2500 

106 

0.9434 

131 

0.7634 

65 

.8182 

81 

1.2346 

107 

0.9346 

132 

0.7576 

56 

.7857 

82 

1.2195 

108 

0.9259 

133 

0.7519 

57 

.7544 

83 

1.2048 

109 

0.9174 

134 

0.7463 

58 

.7241 

84 

1.1905 

110 

0.9091 

135 

0.7408 

69 

.6949 

85 

1.1765 

111 

0.9009 

136 

0.7353 

60 

.6667 

86 

1.1628 

112 

0.8929 

137 

0.7299 

61 

.6393 

87 

1.1494 

113 

0.8850 

138 

0.7246 

62 

.6129 

88 

1.1364 

114 

0.8772 

139 

0.7194 

63 

.5873 

89 

1.1236 

115 

0.8696 

140 

0.7143 

64 

.6625 

90 

1.1111 

116 

0.8621 

141 

0.7092 

65 

.5385 

91 

1.0989 

117 

0.8547 

142 

0.7042 

66 

.5152 

92 

1.0870 

118 

0.8475 

143 

0.6993 

67 

.4925 

93 

1.0753 

119 

0.8403 

144 

0.6944 

68 

1.4706 

94 

1.0638 

120 

0.8333 

145 

0.6897 

69 

1.4493 

95 

1.0526 

121 

0.8264 

146 

0.6850 

70 

1.4286 

96 

1.0417 

122 

0.8197 

147 

0.6803 

71 

1.4085 

97 

1.0309 

123 

0.8130 

148 

0.6757 

72 

1.3889 

98 

1.0204 

124 

0.8065 

149 

0.6711 

73 

1.3699 

99 

1.0101 

125 

0.8000 

150 

0.6667 

74 

1.3514 

100 

1.0000 

126 

0.7937 

75 

1.3333 

101 

0.9901 

APPENDIX. 


515 


6.   Comparison  between  Specific  Gravity  Figures,  Degree  Bourne  and  Degree 
Brix  (as  used  for  sugar  solutions). 


Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

•-a5 

8s 

Percentage 
:  of  sugar  ac- 
!   cording  to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

«o> 

II 
F 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix 

Specific 
gravity. 

sl 

0.0 

1.00000 

0.00 

5.0 

1.01970 

2.84 

10.0 

1.04014 

5.67 

0.1 

1.00038 

0.06 

5.1 

1.02010 

2.89 

10.1 

.04055 

5.72 

0.2 

1.00077 

0.11 

5.2 

1.02051 

2.95 

10.2 

.04097 

5.78 

0.3 

1.00116 

0.17 

5.3 

1.02091 

3.01 

10.3 

.04139 

5.83 

0.4 

100155 

0.23 

5.4 

1.02131 

3.06 

10.4 

.04180 

5.89 

0.5 

1.00193 

0.28 

5.5 

1.02171 

3.12 

10.5 

.04222 

5.95 

0.6 

1.00232 

0.34 

5.6 

1.02211 

3.18 

10.6 

.04264 

6.00 

0.7 

1.00271 

0.40 

5.7 

1.02252 

3.23 

10.7 

.04306 

6.06 

08 

1.00310 

0.45 

5.8 

1.02292 

3.29 

10.8 

.04348 

6.12 

0.9 

1.00349 

0.51 

59 

1.02333 

3.35 

10.9 

1.04390 

6.17 

1.0 

1.00388 

0.57 

6.0 

1.02373 

3.40 

11.0 

1.04431 

6.23 

1.1 

1.00427 

0.63 

6.1 

1.02413 

3.46 

11.1 

1.04473 

6.29 

1.2 

1.00466 

0.68 

6.2 

1.02454 

3.52 

11.2 

1.04515 

6.34 

1.3 

1.00505 

0.74 

6.3 

1.02494 

3.57 

11.3 

1.04557 

6.40 

1.4 

1.00544 

080 

6.4 

1.02535 

3.63 

11.4 

1.04599 

6.46 

1.5 

1.00583 

0.85 

6.6 

1.02575 

3.69 

11.5 

1.04641 

6.51 

1.6 

1.00622 

0.91 

6.6 

1.02616 

3.74 

11.6 

1.04683 

6.57 

1.7 

1.00662 

0.97 

6.7 

1.02657 

3.80 

11.7 

1.04726 

6.62 

1.8 

1.00701 

1.02 

6.8 

1.02697 

3.86 

11.8 

1.04768 

6.68 

1.9 

1.00740 

1.08 

6.9 

1.02738 

3.91 

11.9 

1.04810 

6.74 

2.0 

1.00779 

1.14 

7.0 

1.02779 

3.97 

12.0 

1.04852 

6.79 

2.1 

1.00818 

1.19 

7.1 

1.02819 

4.03 

12.1 

1.04894 

6.85 

2.2 

1.00858 

1.25 

7.2 

1.02860 

4.08 

12.2 

1.04937 

6.91 

2.3 

1.00897 

1.31 

7.3 

1.02901 

4.14 

12.3 

1.04979 

6.96 

2.4 

1.00936 

1.36 

7.4 

1.02942 

4.20 

12.4 

1.05021 

7.02 

2.5 

1.00976 

1.42 

7.5 

1.02983 

4.25 

12.5 

1.05064 

7.08 

2.6 

1.01015 

1.48 

7.6 

1.03024 

4.31 

12.6 

1.05106 

7.13 

2.7 

1.01055 

1.53 

7.7 

1.03064 

4.37 

12.7 

1.05149 

7.19 

2.8 

1.01094 

1.59 

7.8 

1.03105 

4.42 

.  128 

1.05191 

7.24 

2.9 

1.01134 

1.65 

7.9 

1.03146 

4.48 

12.9 

1.05233 

7.30 

8.0 

1.01173 

.70 

8.0 

1.03187 

4.53 

13.0 

1.05276 

7.36 

3.1 

1.01213 

.76 

8.1 

1.03228 

4.59 

13.1 

1.05318 

7.41 

3.2 

1.01252 

.82 

8.2 

1.03270 

4.65 

13.2 

1.05361 

7.47 

3.3 

1.01292 

87 

8.3 

1.03311 

4.70 

13.3 

1.05404 

7.53 

3.4 

1.01332 

.93 

8.4 

1.03352 

4.76 

13.4 

1.05446 

7.58 

3.6 

1.01371 

.99 

8.5 

1.03393 

4.82 

13.5 

1.05489 

7.64 

3.6 

1.01411 

2.04 

8.6 

1.03434 

4.87 

13.6 

1.05532 

7.69 

3.7 

1.01451 

2.10 

8.7 

1.03475 

4.93 

13.7 

1.05574 

7.75 

3.8 

1.01491 

2.16 

8.8 

1.03517 

4.99 

13.8 

1.05617 

7.81 

3.9 

1.01531 

2.21 

8.9 

1.03558 

5.04 

13.9 

1.05660 

7.86 

4.0 

1.01570 

2.27 

9.0 

1.03599 

5.10 

14.0 

1  05703 

7.92 

4.1 

1.01610 

2.33 

9.1 

1.03640 

5.16 

14.1 

1.05746 

7.98 

4.2 

1.01650 

2.38 

9.2 

1.03682 

5.21 

14.2 

1.05789 

8.03 

4.3 

1.01690 

2.44 

9.3 

1.03723 

5.27 

14.3 

1.05831 

8.09 

4.4 

1.01730 

250 

9.4 

1.03765 

5.33 

14.4 

1.05874 

8.14 

4.5 

1.01770 

2.55 

9.6 

1.03806 

5.38 

14.5 

1.05917 

8.20 

4.6 

1  01810 

2.61 

9.6 

1.03848 

5.44 

14.6 

1.05960 

8.26 

4.7 

1  01850 

2.67 

9.7 

1.03889 

5.50 

14.7 

1.06003 

831 

4.8 

1.01890 

2.72 

9.8 

1.03931 

5.55 

14.8 

1  06047 

8.37 

4.9 

1.01930 

2.78 

9.9 

1.03972 

5.61 

14.9 

1.06090 

8.43 

516 


APPENDIX. 


Comparison  between  Specific  Gravity  Figures,  Degree  Bourne  and  Degree 

Brix. — Continued. 


Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

•<j 

«! 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

.1 

<D  £3 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix 

Specific 
gravity. 

|J 

15.0 

1.06133 

8.48 

20.0 

1.08329 

11.29 

25.0 

1.10607 

14.08 

15.1 

1.06176 

8.54 

20.1 

1.08374 

11.34 

25.1 

1.10653 

14.13 

15.2 

1.06219 

8.59 

20.2 

1.08419 

11.40 

25.2 

1.10700 

14.19 

15.3 

1.06262 

8.65 

20.3 

1.08464 

11.45 

25.3 

.10746 

14.24 

15.4 

1.06306 

8.71 

20.4 

1.08509 

11.51 

25.4 

.10793 

14.30 

15.5 

1.06349 

8.76 

20.5 

1.08553 

1157 

25.5 

.10839 

14.35 

15.6 

1.06392 

8.82 

20.6 

1.08599 

11.62 

25.6 

.10886 

14.41 

15.7 

1.06436 

8.88 

20.7 

1.08643 

11.68 

25.7 

.10932 

14.47 

15.8 

1.06479 

8.93 

20.8 

1.08688 

11.73 

25.8 

.10979 

14.52 

15.9 

1.06522 

8.99 

20.9 

1.08733 

11.79 

25.9 

1.11026 

14.58 

16.0 

1.06566 

9.04 

21.0 

1.08778 

11.85 

26.0 

1.11072 

14.63 

16.1 

1.06609 

9.10 

21.1 

1.08824 

11.90 

26.1 

1.11119 

14.69 

16.2 

1.06653 

9.16 

21.2 

1.08869 

11.96 

26.2 

1.11166 

14.74 

16.3 

1.06696 

9.21 

21.3 

1.08914 

12.01 

26.3 

1.11213 

14.80 

16.4 

1.06740 

9.27 

21.4 

1.08959 

12.07 

26.4 

1.11259 

14.85 

16.5 

1.06783 

9.33 

21.5 

1.09004 

12.13 

26.5 

.11306 

14.91 

16.6 

1.06827 

9.38 

21.6 

1.09049 

12.18 

26.6 

.11353 

14.97 

16.7 

1.06871 

9.44 

21.7 

1.09095 

12.24 

26.7 

.11400 

15.02 

16.8 

1.06914 

9.49 

21.8 

1.09140 

12.29 

26.8 

1.11447 

15.08 

16.9 

1.06958 

9.55 

21.9 

1.09185 

12.35 

26.9 

1.11494 

16.13 

17.0 

1.07002 

9.61 

22.0 

1.09231 

12.40 

27.0 

1.11541 

15.19 

17.1 

1.07046 

9.66 

22.1 

1.09276 

12.46 

27.1 

1.11588 

15.24 

17.2 

1.07090 

9.72 

22.2 

1.09321 

12.52 

27.2 

1.11635 

15.30 

17.3 

1.07133 

9.77 

22.3 

1.09367 

12.57 

27.3 

1.11682 

15.35 

17.4 

1.07177 

9.83 

22.4 

1.09412 

12.63 

27.4 

1.11729 

15.41 

17.5 

1.07221 

9.89 

22.5 

1.09458 

12.68 

27.5 

1.11776 

15.46 

17.6 

1.07265 

9.94 

22.6 

1.09503 

12.74 

27.6 

1.11824 

15.52 

17.7 

1.07309 

10.00 

22.7 

1.09549 

12.80 

27.7 

1.11871 

15.58 

17.8 

1.07358 

10.06 

22.8 

1.09595 

12.85 

27.8 

1.11918 

15.63 

17.9 

1.07397 

10.11 

22.9 

1.09640 

12.91 

27.9 

1.11965 

15.69 

18.0 

1.07441 

10.17 

23.0 

1.09686 

12.96 

28.0 

1.12013 

15.74 

18.1 

.07485 

10.22 

23.1 

1.09732 

13.02 

28.1 

1.12060 

15.80 

18.2 

.07530 

10.28 

23.2 

1.09777 

13.07 

28.2 

.12107 

15.85 

18.3 

.07574 

10.33 

23.3 

1.09823 

13.13 

28.3 

.12155 

15.91 

18.4 

.07618 

10.39 

23.4 

1.09869 

13.19 

28.4 

.12202 

15.96 

18.5 

07662 

10.45 

23.5 

1.09915 

13.24 

28.5 

.12250 

16.02 

18.6 

.07706 

10.50 

23.6 

1.09961 

13.30 

28.6 

.12297 

16.07 

18.7 

.07751 

10.56 

23.7 

1.10007 

13.35 

28.7 

.12345 

16.13 

18.8 

1.07795 

10.62 

23.8 

1.10053 

13.41 

28.8 

.12393 

16.18 

18.9 

1.07839 

10.67 

23.9 

1.10099 

13.46 

28.9 

1.12440 

16.24 

19.0 

1.07884 

10.73 

24.0 

1.10145 

13.52 

29.0 

1.12488 

16.30 

19.1 

1.07928 

10.78 

24.1 

1.10191 

13.58 

29.1 

1.12536 

16.35 

19.2 

1.07973 

10.84 

24.2 

1.10237 

13.63 

29.2 

1.12583 

16.41 

19.3 

1.08017 

10.90 

24.3 

1.10283 

13.69 

29.3 

1.12631 

16.46 

19.4 

1.08062 

10.95 

24.4 

1.10329 

13.74 

29.4 

1.12679 

16.52 

19.5 

1.08106 

11.01 

24.5 

1.10375 

13.80 

29.5 

1.12727 

16.57 

19.6 

1.08151 

11.06 

24.6 

1.10421 

13.85 

29.6 

1.12775 

16.63 

19.7 

1.08196 

11.12 

24.7 

1.10468 

13.91 

29.7 

1.12823 

16.68 

19.8 

1.08240 

11.18 

24.8 

1.10514 

13.96 

29.8 

1.12871 

16.74 

19.9 

1.08285 

11.27 

24.9 

1.10560 

14.02 

29.9 

1.12919 

16.79 

APPENDIX. 


517 


Comparison  between  Specific  Gravity  Figures,  Degree  Baume  and  Degree 

Brix. — Continued. 


Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

| 

I* 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

«a> 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

«c> 

30.0 

1.12967 

16.85 

35.0 

1.15411 

19.60 

40.0 

1.17943 

22.33 

30.1 

1.13015 

16.90 

35.1 

1.15461 

19.66 

40.1 

1.17995 

22.38 

30.2 

1.13063 

16.96 

35.2 

1.15511 

19.71 

40.2 

1.18046 

22.44 

30.3 

1.13111 

17.01 

35.3 

1.15561 

19.76 

40.3 

.18098 

22.49 

30.4 

1.13159 

17.07 

35.4 

1.15611 

19.82 

40.4 

.18150 

22.55 

30.5 

1.13207 

17.12 

35.5 

1.15661 

19.87 

40.5 

.18201 

22.60 

30.6 

1.13255 

17.18 

35.6 

1.15710 

19.93 

40.6 

.18253 

22.66 

30.7 

1.13304 

17.23 

35.7 

1.15760 

19.98 

40.7 

.18305 

22.71 

30.8 

1.13352 

17.29 

35.8 

1.15810 

20.04 

40.8 

.18357 

22.77 

30.9 

1.13400 

17.35 

35.9 

1.15861 

20.09 

40.9 

.18408 

22.82 

31.0 

1.13449 

17.40 

36.0 

1.15911 

20.15 

41.0 

1.18460 

22.87 

31.1 

1.13497 

17.46 

36.1 

1.15961 

20.20 

41.1 

1.18512 

22.93 

31.2 

1.13545 

17.51 

36.2 

1.16011 

20.26 

41.2 

1.18564 

22.98 

31.3 

1.13594 

17.57 

36.3 

1.16061 

20.31 

41.3 

1.18616 

23.04 

31.4 

1.13642 

17.62 

36.4 

1.16111 

20.37 

41.4 

1.18668 

23.09 

31.5 

1.13691 

17.68 

36.5 

1.16162 

20.42 

41.5 

1.18720 

23.15 

31.6 

1.13740 

17.73 

36.6 

1.16212 

20.48 

41.6 

1.18772 

23.20 

31.7 

1.13788 

17.79 

36.7 

1.16262 

20.53 

41.7 

1.18824 

23.25 

31.8 

1.13837 

17.84 

36.8 

1.16313 

20.59 

41.8 

1.18887 

23.31 

31.9 

1.13885 

17.90 

36.9 

1.16363 

20.64 

41.9 

1.18929 

23.36 

32.0 

1.13934 

17.95 

37.0 

1.16413 

20.70 

42.0 

.18981 

23.42 

32.1 

1.13983 

18.01 

37.1 

1.16464 

20.75 

42.1 

.19033 

23.47 

32.2 

1.14032 

18.06 

37.2 

1.16514 

20.80 

42.2 

.19086 

23.62 

32.3 

1.14081 

18.12 

37.3 

1.16565 

20.86 

42.3 

.19138 

23.58 

32.4 

1.14129 

18.17 

37.4 

1.16616 

20.91 

42.4 

.19190 

23.63 

32.5 

1.14178 

18.23 

37.5 

1.16666 

20.97 

42.5 

.19243 

23.69 

32.6 

1.14227 

18.28 

37.6 

1.16717 

21.02 

42.6 

.19295 

23.74 

32.7 

1.14276 

18.34 

37.7 

1.16768 

21.08 

42.7 

.19348 

23.79 

32.8 

1.14325 

18.39 

37.8 

1.16818 

21.13 

42.8 

.19400 

23.85 

32.9 

1.14374 

18.45 

37.9 

1.16869 

21.19 

42.9 

.19453 

23.90 

33.0 

1.14423 

18.50 

38.0 

1.16920 

21.24 

43.0 

.19505 

23.96 

33.1 

1.14472 

18.56 

38.1 

1.16971 

21.30 

43.1 

.19558 

24.01 

33.2 

1.14521 

18.61 

38.2 

1.17022 

21.35 

43.2 

.19611 

24.07 

33.3 

1.14570 

18.67 

38.3 

1.17072 

21.40 

43.3 

.19663 

24.12 

33.4 

1.14620 

18.72 

38.4 

1.17122 

21.46 

43.4 

.19716 

24.17 

33.5 

1.14669 

18.78 

38.5 

1.17174 

21.51 

43.5 

.19769 

24.23 

33.6 

1.14718 

18.83 

38.6 

.17225 

21.57 

43.6 

.19822 

24.28 

33.7 

1.14767 

18.89 

38.7 

.17276 

21.62 

43.7 

.19875 

24.34 

33.8 

1.14817 

18.94 

38.8 

.17327 

21.68 

43.8 

.19927 

24.39 

33.9 

1.14866 

19.00 

38.9 

.17379 

21.73 

43.9 

.19980 

24.44 

34.0 

1.14915 

19.05 

39.0 

.17430 

21.79 

44.0 

1.20033 

24.50 

34.1 

1.14965 

19.11 

39.1 

.17481 

21.84 

44.1 

1.20086 

24.55 

34.2 

1.15014 

19.16 

39.2 

.17532 

21.90 

44.2 

1.20139 

24.61 

34.3 

1.15064 

19.22 

39.3 

.17583 

21.95 

44.3 

1.20192 

24.66 

34.4 

1.15113 

19.27 

39.4 

.17635 

22.00 

44.4 

1.20245 

24.71 

34.5 

1.15163 

19.33 

39.5 

.17686 

22.06 

44.5 

1.20299 

24.77 

34.6 

1.15213 

19.38 

39.6 

.17737 

22.11 

44.6 

1.20352 

24.82 

34.7 

1.15262 

19.44 

39.7 

.17789 

22.17 

44.7 

1.20405 

24.88 

34.8 

1.15312 

19.49 

39.8 

.17840 

22.22 

44.8 

1.20458 

24.93 

34.9 

1.15362 

19.55 

39.9 

.17892 

22.28 

44.9 

1.20512 

24.98 

518 


APPENDIX. 


Comparison  between  Specific  Gravity  Figures,  Degree  Baume  and  Degree 

Brix. — Continued. 


Percentage 
of  sugar  ac- 
cording to 
Balling  or 

Specific 
gravity. 

d 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 

Specific 
gravity. 

<4J 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 

Specific 
gravity. 

;gree 
Baume\ 

degree  Brix. 

2 

degree  Brix. 

1 

degree  Brix. 

P 

45.0 

1.20565 

25.04 

50.0 

1.23278 

27.72 

55.0 

1.26086 

30.37 

45.1 

1.20618 

25.09 

50.1 

1.23334 

27.77 

55.1 

1.26143 

30.42 

45.2 

1.20672 

25.14 

50.2 

1.23389 

27.82 

55.2 

1.26200 

30.47 

45.3 

1.20725 

25.20 

50.3 

1.23444 

27.88 

55.3 

1.26257 

30.53 

45.4 

1.20779 

25.25 

50.4 

1.23499 

27.93 

55.4 

.26314 

30.58 

45.5 

1.20832 

25.31 

50.5 

1.23555 

27.98 

55.5 

.26372 

30.63 

45.6 

1.20886 

25.36 

50.6 

1.23610 

28.04 

55.6 

.26429 

30.68 

45.7 

1.20939 

25.41 

50.7 

1.23666 

28.09 

55.7 

.26486 

30.74 

45.8 

1.20993 

25.47 

50.8 

1.23721 

28.14 

55.8 

.26544 

30.79 

45.9 

1.21046 

25.52 

50.9 

1.23777 

28.20 

55.9 

.26601 

30.84 

46.0 

1.21100 

25.57 

51.0 

1.23832 

28.25 

56.0 

1.26658 

30.89 

46.1 

1.21154 

25.63 

51.1 

1.23888 

28.30 

56.1 

1.26716 

30.95 

46.2 

1.21208 

25.68 

51.2 

1.23943 

28.36 

56.2 

1.26773 

31.00 

46.3 

1.21261 

25.74 

51.3 

1.23999 

28.41" 

56.3 

1.26831 

31.05 

46.4 

1.21315 

25.79 

51.4 

1.24055 

28.46 

56.4 

1.26889 

31.10 

46.5 

1.21369 

25.84 

51.5 

1.24111 

28.51 

56.5 

1.26946 

31.16 

46.6 

1.21423 

25.90 

51.6 

1.24166 

28.57 

56.6 

1.27004 

31.21 

46.7 

1.21477 

25.95 

51.7 

1.24222 

28.62 

56.7 

1.27062 

31.26 

46.8 

1.21531 

26.00 

51.8 

1.24278 

28.67 

56.8 

1.27120 

31.31 

46.9 

1.21585 

26.06 

51.9 

1.24334 

28.73 

56.9 

1.27177 

31.37 

47.0 

1.21639 

26.11 

52.0 

1.24390 

28.78 

57.0 

1.27235 

31.42 

47.1 

1.21693 

26.17 

52.1 

1.24446 

28.83 

57.1 

1.27293 

31.47 

47.2 

1.21747 

26.22 

52.2 

1.24502 

28.89 

57.2 

1.27361 

31.52 

47.3 

1.21802 

26.27 

52.3 

1.24558 

28.94 

57.3 

1.27409 

31.58 

47.4 

1.21856 

26.33 

52.4 

1.24614 

28.99 

57.4 

1.27467 

31.63 

47.5 

1.21910 

26.38 

52.5 

1.24670 

29.05 

57.5 

1.27525 

31.68 

47.6 

1.21964 

26.43 

52.6 

1.24726 

29.10 

57.6 

1.27583 

31.73 

47.7 

1.22019 

26.49 

52.7 

1.24782 

29.15 

57.7 

1.27641 

31.79 

47.8 

1.22073 

26.54 

52.8 

1.24839 

29.20 

57.8 

1.27699 

31.84 

47.9 

1.22127 

26.59 

52.9 

1.24895 

29.26 

57.9 

1.27758 

31.89 

48.0 

1.22182 

26.65 

53.0 

1.24951 

29.31 

58.0 

1.27816 

31.94 

48.1 

1.22236 

26.70 

53.1 

1.25008 

29.36 

58.1 

1.27874 

32.00 

48.2 

1.22291 

26.75 

53.2 

1.25064 

29.42 

58.2 

1.27932 

32.05 

48.3 

1.22345 

26.81 

53.3 

1.25120 

29.47 

58.3 

1.27991 

32.10 

48.4 

1.22400 

26.86 

53.4 

1.25177 

29.52 

58.4 

1.28049 

32.15 

48.5 

1.22455 

26.92 

53.5 

1.25233 

29.57 

58.5 

1.28107 

32.20 

48.6 

1.22509 

26.97 

53.6 

1.25290 

29.63 

58.6 

1.28166 

32.26 

48.7 

1.22564 

27.02 

53.7 

125347 

29.68 

58.7 

1.28224 

32.31 

48.8 

1.22619 

27.08 

53.8 

1.25403 

29.73 

58.8 

1.28283 

32.36 

48.9 

1.22673 

27.13 

53.9 

1.25460 

29.79 

58.9 

1.28342 

32.41 

49.0 

1.22728 

27.18 

54.0 

1.25517 

29.84 

59.0 

1.28400 

32.42 

49.1 

1.22783 

27.24 

54.1 

1.25573 

29.89 

59.1 

1.28459 

32.52 

49.2 

1.22838 

27.29 

54.2 

1.25630 

29.94 

59.2 

1.28518 

32.57 

49.3 

1.22893 

27.34 

54.3 

1.25687 

30.00 

59.3 

1.28576 

32.62 

49.4 

1.22948 

27.40 

54.4 

1.25744 

30.05 

59.4 

1.28635 

32.67 

49.5 

1.23003 

27.45 

54.5 

1.25801 

30.10 

59.5 

1.28694 

32.73 

49.6 

1.23058 

27.50 

54.6 

1.25857 

30.16 

59.6 

1.28753 

32.78 

49.7 

1.23113 

27.56 

54.7 

1.25914 

30.21 

59.7 

1.28812 

32.83 

49.8 

1.23168 

27.61 

54.8 

1.25971 

30.26 

59.8 

1.28871 

32.88 

49.9 

1.23223 

27.66 

54.9 

1.26028 

30.31 

59.9 

1.28930 

32.93 

APPENDIX. 


519 


Comparison  between  Specific  Gravity  Figures,  Degree  Bourne  and  Degree 

Brix. — Continued. 


Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

8| 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

«c> 

0 

r 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

P 

60.0 

.28989 

32.99 

65.0 

.31989 

35.57 

700 

1.35088 

38.12 

60.1 

.29048 

33.04 

65.1 

.32050 

35.63 

70.1 

1.35155 

38.18 

60.2 

.29107 

33.09 

65.2 

.32111 

35.68 

70.2 

1.35214 

38.23 

60.3 

.29166 

33.14 

65.3 

.32172 

35.73 

70.3 

1.35277 

38.28 

60.4 

.29225 

33.20 

65.4 

.32233 

35.78 

70.4 

1.35340 

38.33 

60.5 

.29284 

33.25 

65.5 

.32294 

35.83 

70.5 

1.35403 

38.38 

60.6 

.29343 

33.30 

65.6 

.32355 

35.88 

70.6 

1.35466 

38.43 

60.7 

1.29403 

33.35 

65.7 

.32417 

35.93 

70.7 

1.35530 

38.48 

60.8 

1.29462 

33.40 

65.8 

.32478 

35.98 

70.8 

1.35593 

38.53 

60.9 

1.29521 

33.46 

65.9 

.32539 

36.04 

70.9 

1.35656 

38.58 

61.0 

1.29581 

33.51 

66.0 

.32601 

36.09 

71.0 

1.35720 

38.63 

61.1 

1.29646 

33.56 

66.1 

.32662 

36.14 

71.1 

1.35783 

38.68 

61.2 

1.29700 

33.61 

66.2 

.32724 

36.19 

71.2 

1.35847 

38.73 

61.3 

1.29759 

33.66 

66.3 

.32785 

36.24 

71.3 

1.35910 

38.78 

61.4 

1.29819 

33.71 

66.4 

.32847 

36.29 

71.4 

1.35974 

38.83 

61.5 

1.29878 

33.77 

66.5 

.32908 

36.34 

71.5 

1.36037 

38.88 

61.6 

1.29938 

33.82 

66.6 

.32970 

36.39 

71.6 

1.36101 

38.93 

61.7 

1.29998 

33.87 

66.7 

.33031 

36.45 

71.7 

1.36164 

38.98 

61.8 

.30057 

33.92 

66.8 

.33093 

36.50 

71.8 

1.36228 

39.03 

61.9 

.30117 

33.97 

66.9 

.33155 

36.65 

71.9 

1.36292 

39.08 

62.0 

.30177 

34.03 

67.0 

.33217 

36.60 

72.0 

1.36355 

39.13 

62.1 

.30237 

34.08 

67.1 

.33278 

36.65 

72.1 

1.36419 

39.19 

62.2 

.30297 

34.13 

67.2 

.33340 

36.70 

72.2 

1.36483 

39.24 

62.3 

.30356 

34.18 

67.3 

.83402 

36.75 

72.3 

1.36547 

39.29 

62.4 

.30416 

34.23 

67.4 

.33464 

36.80 

72.4 

1.36611 

39.34 

62.5 

.30476 

34.28 

67.5 

.33526 

36.85 

72.5 

1.36675 

39.39 

62.6 

.30536 

34.34 

67.6 

.33588 

36.90 

72.6 

1.36739 

39.44 

62.7 

.30596 

34.39 

67.7 

.33650 

36.96 

72.7 

1.36803 

39.49 

62.8 

1.30657 

34.44 

67.8 

.33712 

37.01 

72.8 

1.36867 

39.54 

62.9 

1.30717 

34.49 

67.9 

.33774 

37.06 

72.9 

1.86931 

39.69 

63.0 

1.30777 

34.54 

68.0 

.33836 

37.11 

73.0 

1.36995 

39.64 

63.1 

1.30837 

34.59 

68.1 

.33899 

37.16 

73.1 

1.37059 

39.69 

63.2 

1.30897 

34.65 

68.2 

.33961 

37.21 

73.2 

1.37124 

39.74 

63.3 

1.30958 

34.70 

68.3 

.34023 

37.26 

73.3 

1.37188 

39.79 

63.4 

1.31018 

34.75 

68.4 

.34085 

37.81 

73.4 

1.37252 

39.84 

63.5 

1.31078 

34.80 

68.5 

.34148 

37.36 

73.5 

1.37317 

39.89 

63.6 

1.31139 

34.85 

68.6 

.34210 

37.41 

73.6 

1.37381 

39.94 

63.7 

1.31199 

34.90 

68.7 

.34273 

37.47 

73.7 

1.37446 

39.99 

63.8 

1.31260 

34.96 

68.8 

.34335 

37.52 

73.8 

1.37510 

40.04 

63.9 

1.31320 

35.01 

68.9 

.34398 

37.57 

73.9 

1.37575 

40.09 

64.0 

1.31381 

35.06 

69.0 

.34460 

37.62 

74.0 

1.37639 

40.14 

64.1 

1.31442 

35.11 

69.1 

.34523 

37.67 

74.1 

"1.37704 

40.19 

64.2 

.31502 

35.16 

69.2 

.34525 

37.72 

74.2 

1.37768 

40.24 

64.3 

.31563 

35.21 

69.3 

.34648 

37.77 

74.3 

1.37833 

40.29 

64.4 

.31624 

35.27 

69.4 

1.34711 

37.82 

74.4 

1.37898 

40.34 

64.5 

.31684 

35.32 

69.5 

1.34774 

37.87 

74.5 

1.37962 

40.39 

64.6 

.31745 

35.37 

69.6 

1.34836 

37.92 

74.6 

1.38027 

40.44 

64.7 

.31806 

35.42 

69.7 

1.34899 

37.97 

74.7 

1.38092 

40.49 

64.8 

.31867 

35.47 

69.8 

1.34962 

38.02 

74.8 

1.38157 

40.54 

64.9 

1.31928 

35.52 

69.9 

1.35025 

38.07 

74.9 

1.38222 

40.59 

520 


APPENDIX. 


Comparison  between  Specific  Gravity  Figures,  Degree  Bourne  and  Degree 

Brix. — Continued. 


Percentage 

3 

Percentage 

*£ 

Percentage 

xi5 

of  sugar  ac- 
cording to 
Balling  or 

Specific 
gravity. 

wl 

of  sugar  ac- 
cording to 
Balling  or 

Specific 
gravity. 

p 

of  sugar  ac- 
cording to 
Balling  or 

Specific 
gravity. 

»| 

«  3 
&B 

degree  Brix. 

1 

degree  Brix. 

ft 

degree  Brix. 

ft 

75.0 

.38287 

40.64 

80.0 

1.41586 

43.11 

85.0 

1.44986 

45.54 

75.1 

.38352 

40.69 

80.1 

1.41653 

43.61 

85.1 

1.45055 

45.59 

75.2 

.38417 

40.74 

80.2 

.41720 

43.21 

85.2 

1.45124 

45.64 

75.3 

.38482 

40.79 

80.3 

.41787 

43.26 

85.3 

1.45193 

45.69 

75.4 

.38547 

40.84 

80.4 

.41854 

43.31 

85.4 

1.45262 

45.74 

75.5 

.38612 

40.89 

80.5 

.41921 

43.36 

85.5 

1.45331 

45.78 

75.6 

.38677 

40.94 

80.6 

.41989 

43.41 

85.6 

.45401 

45.83 

75.7 

.38743 

40.99 

80.7 

.42056 

43.45 

85.7 

.45470 

45.88 

75.8 

.38808 

41.04 

80.8 

.42123 

43.50 

85.8 

.45539 

45.93 

75.9 

.38873 

41.09 

80.9 

.42190 

43.55 

85.9 

.45609 

45.98 

76.0 

1.38939 

41.14 

81.0 

.42258 

43.60 

86.0 

1.45678 

46.02 

76.1 

1.39004 

41.19 

81.1 

.42325 

43.65 

86.1 

.45748 

46.07 

76.2 

1.39070 

41.24 

81.2 

.42393 

43.70 

86.2 

.45817 

46.12 

76.3 

1.39135 

41.29 

81.3 

.42460 

43.75 

86.3 

.45887 

46.17 

76.4 

.39201 

41.33 

81.4 

.42528 

43.80 

86.4 

.45956 

46.22 

76.5 

.39266 

41.38 

81.5 

.42595 

43.85 

86.5 

.46026 

46.26 

76.6 

.39332 

41.43 

81.6 

.42663 

43.89 

86.6 

.46095 

46.31 

76.7 

.39397 

41.48 

81.7 

.42731 

43.94 

86.7 

.46165 

46.36 

76.8 

.39463 

41.53 

81.8 

.42798 

43.99 

86.8 

.46235 

46.41 

76.9 

.39529 

41.58 

81.9 

.42866 

44.04 

86.9 

.46304 

46.46 

77.0 

1.39595 

41.63 

82.0 

.42934 

44.09 

87.0 

1.46374 

46.50 

77.1 

1.39660 

41.68 

82.1 

.43002 

44.14 

87.1 

1.46444 

46.55 

77.2 

1.39726 

41.73 

82.2 

.43070 

44.19 

87.2 

1.46514 

46.60 

77.3 

1.39792 

41.78 

82.3 

.43137 

44.24 

87.3 

1.46584 

46.65 

77.4 

1.39858 

41.83 

82.4 

.43205 

44.28 

87.4 

1.46654 

46.69 

77.5 

1.39924 

41.88 

82.5 

.43273 

44.33 

87.5 

1.46724 

46.74 

77.6 

1.39990 

41.93 

82.6 

.43341 

44.38 

87.6 

1.46794 

46.79 

77.7 

1.40056 

41.98 

82.7 

.43409 

44.43 

87.7 

1.46864 

46.84 

77.8 

1.40122 

42.03 

82.8 

.43478 

44.48 

87.8 

1.46934 

46.88 

77.9 

1.40188 

42.08 

82.9 

.43546 

44.53 

87.9 

1.47004 

46.93 

78.0 

1.40254 

42.13 

83.0 

.43614 

44.58 

88.0 

1.47074 

46.98 

78.1 

1.40321 

42.18 

83.1 

.43682 

44.62 

88.1 

1.47145 

47.03 

78.2 

1.40387 

42.23 

83.2 

.43750 

44.67 

88.2 

1.47215 

47.08 

78.3 

1.40453 

42.28 

83.3 

1.43819 

44.72 

88.3 

1.47285 

47.12 

78.4 

1.40520 

42.32 

83.4 

1.43887 

44.77 

88.4 

1.47356 

47.17 

78.5 

1.40586 

42.37 

83.5 

1.43955 

44.82 

88.5 

1.47426 

47.22 

78.6 

1.40652 

42.42 

83.6 

1.44024 

44.87 

88.6 

1.47496 

47.27 

78.7 

1.40719 

42.47 

83.7 

.44092 

44.91 

88.7 

1.47567 

47.31 

78.8 

1.40785 

42.52 

83.8 

.44161 

44.96 

88.8 

1.47637 

47.36 

78.9 

1.40852 

42.57 

83.9 

.44229 

45.01 

88.9 

1.47708 

47.41 

79.0 

1.40918 

42.62 

84.0 

.44298 

45.06 

89.0 

1.47778 

47.46 

79.1 

1.40985 

42.67 

84.1 

.44367 

45.11 

89.1 

1.47849 

47.50 

79.2 

1.41052 

42.72 

84.2 

.44435 

45.16 

89.2 

.47920 

47.55 

79.3 

1.41118 

42.77 

84.3 

.44504 

45.21 

89.3 

.47991 

47.60 

79.4 

1.41185 

42.82 

84.4 

.44573 

45.25 

89.4 

.48061 

47.65 

79.5 

1.41252 

42.87 

84.5 

.44641 

45.30 

89.5 

.48132 

47.69 

79.6 

1.41318 

42.92 

84.6 

.44710 

45.35 

89.6 

.48203 

47.74 

79.7 

1.41385 

42.96 

84.7 

1.44779 

45.40 

89.7 

.48274 

47.79 

79.8 

1.41452 

43.01 

84.8 

1.44848 

45.45 

89.8 

.48345 

47.83 

79.9 

1.41519 

43.06 

84.9 

1.44917 

45.49 

89.9 

.48416 

47.88 

APPENDIX. 


521 


Comparison  between  Specific  Gravity  Figures,  Degree  Baume  and  Degree 

Brix. — Continued. 


Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

J 

Q)    3 

fe-5 
1* 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

i| 

*" 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

xu 

$1 
f 

90.0 

1.48486 

47.93 

94.0 

1.51359 

49.81 

98.0 

.54290 

51.65 

90.1 

1.48558 

47.98 

94.1 

1.51431 

49.85 

98.1 

.54365 

51.70 

90.2 

1.48629 

48.02 

94.2 

1.51504 

49.90 

98.2 

.54440 

51.74 

90.3 

.48700 

48.07 

94.3 

1.51577 

49.94 

98.3 

.54515 

51.79 

90.4 

.48771 

48.12 

94.4 

1.51649 

49.99 

98.4 

.54590 

51.83 

90.5 

1.48842 

48.17 

94.5 

1.51722 

50.04 

98.5 

.54665 

51.88 

90.6 

.48913 

48.21 

94.6 

1.51795 

50.08 

98.6 

.54740 

51.92 

90.7 

1.48985 

48.26 

94.7 

1.51868 

50.13 

98.7 

.54815 

51.97 

90.8 

1.49056 

48.31 

94.8 

1.51941 

50.18 

98.8 

.54890 

52.01 

90.9 

1.49127 

48.35 

94.9 

1.52014 

50.22 

98.9 

.54965 

52.06 

91.0 

1.49199 

48.40 

95.0 

1.52087 

50.27 

99.0 

1.55040 

52.11 

91.1 

1.49270 

48.45 

95.1 

1.52159 

50.32 

99.1 

1.55115 

52.15 

91.2 

.49342 

48.50 

95.2 

1.52232 

50.36 

99.2 

1.55189 

52.20 

91.3 

.49413 

48.54 

95.3 

1.52304 

50.41 

99.3 

1.55264 

52.24 

91.4 

.49485 

48.59 

95.4 

1.52376 

50.45 

99.4 

1.55338 

52.29 

91.5 

.49556 

48.64 

95.5 

1.52449 

50.50 

99.5 

1.55413 

52.33 

91.6 

.49628 

48.68 

95.6 

1.52521 

50.55 

99.6 

1.55487 

62.38 

91.7 

.49700 

48.73 

95.7 

1.52593 

50.59 

99.7 

1.55562 

52.42 

91.8 

.49771 

48.78 

95.8 

1.52665 

50.64 

99.8 

1.55636 

52.47 

91.9 

1.49843 

48.82 

95.9 

1.52738 

50.69 

99.9 

1.65711 

52.51 

92.0 

1.49915 

48.87 

96.0 

1.52810 

50.73 

100.0 

1.55785 

52.56 

92.1 

1.49987 

48.92 

96.1 

1.52884 

50.78 

92.2 

.50058 

48.96 

96.2 

1.52958 

50.82 

92.3 

.50130 

49.01 

96.3 

1.53032 

50.87 

92.4 

.50202 

49.06 

96.4 

1.53106 

50.92 

92.5 

.50274 

49.11 

96.5 

1.53180 

50.96 

92.6 

.50346 

49.15 

96.6 

1.53254 

51.01 

92.7 

.50419 

49.20 

96.7 

1.53328 

51.05 

92.8 

.50491 

49.25 

96.8 

1.53402 

51.10 

92.9 

.50563 

49.29 

96.9 

1.53476 

51.15 

93.0 

1.50633 

49.34 

97.0 

.53550 

51.19 

93.1 

1.50707 

49.39 

97.1 

.53624 

51.24 

93.2 

.50779 

49.43 

97.2 

.53698 

51.28 

93.3 

.50852 

49.48 

97.3 

.53772 

51.33 

93.4 

.50924 

49.53 

97.4 

.53846 

51.38 

93.5 

.50996 

49.57 

97.5 

.53920 

51.42 

93.6 

.51069 

49.62 

97.6 

.53994 

51.47 

93.7 

.51141 

49.67 

97.7 

.54068 

51.51 

93.8 

.51214 

49.71 

97.8 

.54142 

51.56 

93.9 

.51286 

49.76 

97.9 

.54216 

51.60 

522 


APPENDIX. 


IV.   Alcohol  Tables. 

Percentage  of  Alcohol  by  Weight  and  by  Volume  from  the  Specific  Gravity 
(at  15.5°  G),  by  Otto  Hehner. 


Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Per  cent- 
age  of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

1.0000 

0.00 

0.00 

0.9999 

0.05 

0.07 

0.9949 

2.89 

3.62 

0.9899 

5.94 

7.40 

8 

0.11 

0.13 

8 

2.94 

3.69 

8 

6.00 

7.48 

7 

0.16 

0.20 

7 

3.00 

3.76 

7 

6.07 

7.57 

6 

0.21 

0.26 

6 

3.06 

3.83 

6 

6.14 

7.66 

5 

0.26 

0.33 

5 

3.12 

3.90 

5 

6.21 

7.74 

4 

0.32 

0.40 

4 

3.18 

3.98 

4 

6.28 

7.83 

3 

0.37 

0.46 

3 

3.24 

4.05 

3 

6.36 

7.92 

2 

0.42 

0.53 

2 

3.29 

4.12 

2 

6.43 

8.01 

1 

0.47 

0.60 

1 

3.35 

4.20 

1 

6.50 

8.10 

0 

0.53 

0.66 

0 

3.41 

4.27 

0 

6.57 

8.18 

0.9989 

0.58 

0.73 

0.9939 

3.47 

4.34 

0.9889 

6.64 

8.27 

8 

0.63 

0.79 

8 

3.53 

4.42 

8 

6.71 

8.36 

7 

0.68 

0.86 

7 

3.59 

4.49 

7 

6.78 

8.45 

6 

0.74 

0.93 

6 

3.65 

4.56 

6 

6.86 

8.54 

5 

0.79 

0.99 

5 

3.71 

4.63 

5 

6.93 

8.63 

4 

0.84 

1.06 

4 

3.76 

4.71 

4 

7.00 

8.72 

3 

0.89 

1.13 

3 

3.82 

4.78 

3 

7.07 

8.80 

2 

0.95 

1.19 

2 

3.88 

4.85 

2 

7.13 

8.88 

1 

.00 

.26 

1 

3.94 

4.93 

1 

7.20 

8.96 

0 

.06 

.34 

0 

4.00 

5.00 

0 

7.27 

9.04 

0.9979 

.12 

.42 

0.9929 

4.0G 

5.08 

0.9879 

7.33 

9.13 

8 

.19 

.49 

8 

4.12 

5.16 

8 

7.40 

9.21 

7 

.25 

.57 

7 

4.19 

5.24 

7 

7.47 

9.29 

6 

.31 

.65 

6 

4.25 

5.32 

6 

7.53 

9.37 

5 

.37 

.73 

6 

4.31 

5.39 

5 

7.60 

9.45 

4 

.44 

.81 

4 

4.37 

5.47 

4 

7.67 

9.54 

3 

.50 

.88 

3 

4.44 

5.55 

3 

7.73 

9.62 

2 

.56 

.96 

2 

4.50 

5.63 

2 

7.80 

9.70 

1 

.62 

2.04 

1 

4.56 

5.71 

1 

7.87 

9.78 

0 

.69 

2.12 

0 

4.62 

5.78 

0 

7.93 

9.86 

0.9969 

.75 

2.20 

0.9919 

4.69 

5.86 

0.9869 

8.00 

9.95 

8 

.81 

2.27 

8 

4.75 

5.94 

8 

8.07 

10.03 

7 

1.87 

2.35 

7 

4.81 

6.02 

7 

8.14 

10.12 

6 

1.94 

2.43 

6 

4.87 

6.10 

6 

8.21 

10.21 

5 

2.00 

2.51 

5 

4.94 

6.17 

5 

8.29 

10.30 

4 

2.06 

2.58 

4 

500 

6.24 

4 

8.36 

10.38 

3 

2.11 

2.62 

3 

5.06 

6.32 

3 

8.43 

10.47 

2 

2.17 

2.72 

2 

5.12 

6.40 

2 

8.50 

10.56 

1 

2.22 

2.79 

1 

5.19 

6.48 

1 

8.57 

10.65 

0 

2.28 

2.86 

0 

5.25 

6.55 

0 

8.64 

10.73 

0.9959 

2.33 

2  no 
•  «fo 

0.9909 

5.31 

6.63 

0.9859 

8.71 

10.82 

8 

2.39 

3.00 

8 

5.37 

6.71 

8 

8.79 

10.91 

7 

2.44 

3.07 

7 

5.44 

6.78 

7 

8.86 

11.00 

6 

2.50 

3.14 

6 

5.50 

6.86 

6 

8.93 

11.08 

5 

2.56 

3.21 

5 

5.56 

6.94 

5 

9.00 

11.17 

4 

2.61 

3.28 

4 

5.62 

7.01 

4 

9.07 

11.26 

3 

2.67 

3.35 

3 

5.69 

7.09 

3 

9.14 

11.35 

2 

2.72 

3.42 

2 

5.75 

7.17 

2 

9.21 

11.44 

1 

2.78 

3.49 

1 

5.81 

7.25 

1 

9.29 

11.52 

0 

2.83 

3.55 

0 

5.87 

7.32 

0 

9.36 

11.61 

APPENDIX. 


523 


Percentage  of  Alcohol  by  Weight  and  by  Volume  from  the  Specific  Gravity 
(at  15.5°  C.\  by  Otto  Hehner. — Continued. 


Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  b; 
weight. 

Percent- 
age of 
absolute 
alcohol  b; 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  a 
15.5°  C. 

Percent- 
age of 

absolute 
alcohol  b 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

0.9849 

9.43 

11.70 

0.9799 

13.23 

16.33 

0.9749 

17.33 

21.29 

8 

9.50 

11.79 

8 

13.31 

16.43 

8 

17.42 

21.39 

7 

9.57 

11.87 

7 

13.38 

16.52 

7 

17.50 

21.49 

6 

9.64 

11.96 

6 

13.46 

16.61 

6 

17.58 

21.59 

5 

9.71 

12.05 

5 

13.54 

16.70 

C 
C 

17.67 

21.69 

4 

9.79 

12.13 

4 

13.62 

16.80 

4 

17.75 

21.79 

3 

9.86 

12.22 

3 

13.69 

16.89 

3 

17.83 

21.89 

2 

9.93 

12.31 

2 

13.77 

16.98 

2 

17.92 

21.99 

1 

10.00 

12.40 

1 

13.85 

17.08 

1 

18.00 

22.09 

0 

10.08 

12.49 

0 

13.92 

17.17 

0 

18.08 

22.18 

0.9839 

10.15 

12.58 

0.9789 

14.00 

17.26 

0.9739 

18.15 

22.27 

8 

10.23 

12.68 

8 

14.09 

17.37 

8 

18.23 

22.36 

7 

10.31 

12.77 

7 

14.18 

17.48 

7 

18.31 

22.46 

6 

10.38 

12.87 

6 

14.27 

17.59 

6 

18.38 

22.65 

5 

10.46 

12.96 

5 

14.36 

17.70 

5 

18.46 

22.64 

4 

10.54 

13.05 

4 

14.45 

17.81 

4 

18.54 

22.73 

3 

10.62 

13.15 

3 

14.55 

17.92 

3 

18.62 

22.82 

2 

10.69 

13.24 

2 

14.64 

18.03 

2 

18.69 

22.92 

1 

10.77 

13.34 

1 

14.73 

18.14 

1 

18.77 

23.01 

0 

10.85 

13.43 

0 

14.82 

18.25 

0 

18.85 

23.10 

0.9829 

10.92 

13.52 

0.9779 

14.90 

18.36 

0.9729 

18.92 

23.19 

8 

11.00 

13.62 

8 

15.00 

18.48 

8 

19.00 

23.28 

7 

11.08 

13.71 

7 

15.08 

18.58 

7 

19.08 

23.38 

6 

11.15 

13.81 

6 

15.17 

18.68 

6 

19.17 

23.48 

5 

11.23 

13.90 

5 

15.25 

18.78 

5 

19.25 

23.58 

4 

11.31 

13.99 

4 

15.33 

18.88 

4 

19.33 

23.68 

3 

11.38 

14.09 

3 

15.42 

18.98 

3 

19.42 

23.78 

2 

11.46 

14.18 

2 

15.50 

19.08 

2 

19.50 

23.88 

1 

11.54 

14.27 

1 

15.58 

19.18 

1 

19.58 

23.98 

0 

11.62 

14.37 

0 

15.67 

19.28 

0 

19.67 

24.08 

0.9819 

11.69 

14.46 

0.9769 

15.75 

19.39 

0.9719 

19.75 

24.18 

8 

11.77 

14.56 

8 

15.83 

19.49 

8 

19.83 

24.28 

7 

11.85 

14.65 

7 

15.92 

19.59 

7 

19.92 

24.38 

6 

11.92 

14.74 

6 

16.00 

19.68 

6 

20.00 

24.48 

5 

12.00 

14.84 

5 

16.08 

19.78 

6 

20.08 

24.58 

4 

12.08 

14.93 

4 

16.15 

19.87 

4 

20.17 

24.68 

3 

12.15 

15.02 

3 

16.23 

19.96 

3 

20.25 

24.78 

2 

12.23 

15.12 

2 

16.31 

20.06 

2 

20.33 

24.88 

1 

12.31 

15.21 

1 

16.38 

20.15 

1 

20.42 

24.98 

0 

12.38 

15.30 

0 

16.46 

20.24 

0 

20.50 

25.07 

0.9809 

12.46 

15.40 

0.9759 

16.54 

20.33 

0.9709 

20.58 

25.17 

8 

12.54 

15.49 

8 

16.62 

20.43 

8 

20.67 

25.27 

7 

12.62 

15.58 

7 

16.69 

20.52 

7 

20.75 

25.37 

6 

12.69 

15.68 

6 

16.77 

20.61 

6 

20.83 

25.47 

5 

12.77 

15.77 

5 

16.85 

20.71 

6 

20.92 

25.57 

4 

12.85 

15.86 

4 

16.92 

20.80 

4 

21.00 

25.67 

3 

12.92 

15.96 

3 

17.00 

20.89 

3 

21.08 

25.76 

2 

13.00 

16.05 

2 

17.08 

*0.99 

2 

21.15 

25.86 

1 

13.08 

16.15 

1 

17.17 

21.09 

1 

21.23 

25.95 

0 

13.15 

16.24 

0 

17.25 

21.19 

0 

21.31 

26.04 

524 


APPENDIX. 


Percentage  of  Alcohol  by  Weight  and  by  Volume  from  the  Specific  Gravity 
(at  15.5°  C.\  by  Otto  Hehner.— Continued. 


Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

0.9699 

21.38 

26.13 

0.9649 

25.21 

30.65 

0.9599 

28.62 

34.61 

8 

21.46 

26.22 

8 

25.29 

30.73 

8 

28.69 

34.69 

7 

21.54 

26.31 

7 

25.36 

30.82 

7 

28.75 

34.76 

6 

21.62 

26.40 

6 

25.43 

30.90 

6 

28.81 

34.83 

5 

21.69 

26.49 

6 

25.50 

30.98 

5 

28.87 

34.90 

4 

21.77 

26.58 

4 

25.57 

31.07 

4 

28.94 

34.97 

3 

21.85 

26.67 

3 

25.64 

31.15 

3 

29.00 

35.05 

2 

21.92 

26.77 

2 

25.71 

31.23 

2 

29.07 

35.12 

1 

22.00 

26.86 

1 

25.79 

31.32 

1 

29.13 

35.20 

0 

22.08 

26.95 

0 

25.86 

31.40 

0 

29.20 

35.28 

0.9689 

22.15 

27.04 

0.9639 

25.93 

31.48 

0.9589 

29.2? 

35.35 

8 

22.23 

27.13 

8 

26.00 

31.57 

8 

29.33 

35.43 

7 

22.31 

27.22 

7 

26.07 

31.65 

7 

29.40 

35.51 

6 

22.38 

27.31 

6 

26.13 

31.72 

6 

29.47 

35.58 

5 

22.46 

27.40 

6 

26.20 

31.80 

5 

29.53 

35.66 

4 

22.64 

27.49 

4 

26.27 

31.88 

4 

29.60 

35.74 

3 

22.62 

27.59 

3 

26.33 

31.96 

3 

29.67 

35.81 

2 

22.69 

27.68 

2 

26.40 

32.03 

2 

29.73 

35.89 

1 

22.77 

27.77 

1 

26.47 

32.11 

1 

29.80 

35.97 

0 

22.85 

27.86 

0 

26.63 

32.19 

0 

29.87 

36.04 

0.9679 

22.92 

27.95 

0.9629 

26.60 

32.27 

0.9579 

29.93 

36.12 

8 

23.00 

28.04 

8 

26.67 

32.34 

8 

30.00 

36.20 

7 

23.08 

28.13 

7 

26.73 

32.42 

7 

30.06 

36.26 

6 

23.15 

28.22 

6 

26.80 

32.50 

6 

30.11 

36.32 

6 

23.23 

28.31 

6 

26.87 

32.58 

5 

30.17 

36.39 

4 

23.31 

28.41 

4 

26.93 

32.65 

4 

30.22 

36.45 

3 

23.38 

28.60 

3 

27.00 

32.73 

3 

30.28 

36.51 

2 

23.46 

28.59 

2 

27.07 

32.81 

2 

30.33 

36.57 

1 

23.54 

28.68 

1 

27.14 

32.90 

1 

30.39 

36.64 

0 

23.62 

28.77 

0 

27.21 

32.98 

0 

30.44 

36.70 

0.9669 

23.69 

28.86 

0.9619 

27.29 

33.06 

0.9569 

30.50 

36.76 

8 

23.77 

28.95 

8 

27.36 

33.15 

8 

30.56 

36.83 

7 

23.85 

29.04 

7 

27.43 

33.23 

7 

30.61 

36.89 

6 

23.92 

29.13 

6 

27.60 

33.31 

6 

30.67 

36.95 

6 

24.00 

29.22 

6 

27.57 

33.39 

5 

30.72 

37.02 

4 

24.08 

29.31 

4 

27.64 

33.48 

4 

30.78 

37.08 

3 

24.16 

29.40 

3 

27.71 

33.56 

3 

30.83 

37.14 

2 

24.23 

29.49 

2 

27.79 

33.64 

2 

30.89 

37.20 

1 

24.31 

29.58 

1 

27.86 

33.73 

1 

30.94 

37.27 

0 

24.38 

29.67 

0 

27.93 

33.81 

0 

31.00 

37.34 

0.9659 

24.46 

29.76 

0.9609 

28.00 

33.89 

0.9559 

31.06 

37.41 

8 

24.54 

29.86 

8 

28.06 

33.97 

8 

31.12 

37.48 

7 

24.62 

29.95 

7 

28.12 

34.04 

7 

31.19 

37.55 

6 

24.69 

30.04 

6 

28.19 

34.11 

6 

31.25 

37.62 

6 

24.77 

30.13 

6 

28.25 

34.18 

5 

31.31 

37.69 

4 

24.85 

30.22 

4 

28.31 

34.25 

4 

31.37 

37.76 

3 

24.92 

30.31 

3 

28.37 

34.33 

3 

31.44 

37.83 

2 

25.00 

30.40 

2 

28.44 

34.40 

2 

31.50 

37.90 

1 

25.07 

30.48 

1 

28.50 

34.47 

1 

31.56 

37.97 

0 

25.14 

30.67 

0 

28.66 

34.54 

0 

31.62 

38.04 

APPENDIX. 


525 


Percentage  of  Alcohol  by  Weight  and  by  Volume  from  the  Specific  Gravity 
(at  15.5°  G),  by  Otto  Hehner.— Continued. 


Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

0.9549 

31.69 

38.11 

0.9499 

34.57 

41.37 

0.9449 

37.17 

44.24 

8 

31.75 

38.18 

8 

34.62 

41.42 

8 

37.22 

44.30 

7 

31.81 

38.25 

7 

34.67 

41.48 

7 

37.28 

44.36 

6 

31.87 

38.33 

6 

34.71 

41.53 

6 

37.33 

44.43 

5 

31.94 

38.40 

5 

34.76 

41.58 

5 

37.39 

44.49 

4 

32.00 

38.47 

4 

34.81 

41.63 

4 

37.44 

44.55 

3 

32.06 

38.53 

3 

34.86 

41.69 

3 

37.50 

44.61 

2 

32.12 

38.60 

2 

34.90 

41.74 

2 

37.56 

44.67 

1 

32.19 

38.68 

1 

34.95 

41.79 

1 

37.61 

44.73 

0 

32.25 

38.75 

0 

35.00 

41.84 

0 

37.67 

44.79 

0.9539 

«)»>    01 

OZaOl 

38.82 

0.9489 

35.05 

41.90 

0.9439 

37.72 

44.86 

8 

32.37 

38.89 

8 

35.10 

41.95 

8 

37.78 

44.92 

7 

32.44 

38.96 

7 

35.15 

42.01 

7 

37.83 

44.98 

6 

32.50 

39.04 

6 

35.20 

42.06 

6 

37.89 

45.04 

5 

32.56 

39.11 

5 

35.25 

42.12 

5 

37.94 

45.10 

4 

32.62 

39.18 

4 

35.30 

42.17 

4 

38.00 

45.16 

3 

32.69 

39.25 

3 

35.35 

42.23 

3 

38.06 

45.22 

2 

32.75 

39.32 

2 

35.40 

42.29 

2 

38.11 

45.28 

1 

32.81 

39.40 

1 

35.45 

42.34 

1 

38.17 

45.34 

0 

32.87 

39.47 

0 

35.50 

42.40 

0 

38.22 

45.41 

0.9529 

32.94 

39.54 

0.9479 

35.55 

42.45 

0.9429 

38.28 

45.47 

8 

33.00 

39.61 

8 

35.60 

42.51 

8 

38.33 

45.53 

7 

33.06 

39.68 

7 

35.65 

42.56 

7 

38.39 

45.59 

6 

33.12 

39.74 

6 

35.70 

42.62 

6 

38.44 

45.65 

5 

33.18 

39.81 

5 

35.75 

42.67 

5 

38.50 

45.71 

4 

33.24 

39.87 

4 

35.80 

42.73 

4 

38.56 

45.77 

3 

33.29 

39.94 

3 

35.85 

42.78 

3 

38.61 

45.83 

2 

33.35 

40.01 

2 

35.90 

42.84 

2 

38.67 

45.89 

1 

33.41 

40.07 

1 

35.95 

42.89 

1 

38.72 

45.95 

0 

33.47 

40.14 

0 

36.00 

42.95 

0 

38.78 

46.02 

0.9519 

33.53 

40.20 

0.9469 

36.06 

43.01 

0.9419 

38.83 

46.08 

8 

33.59 

40.27 

8 

36.11 

43.07 

8 

38.89 

46.14 

7 

33.65 

40.34 

7 

36.17 

43.13 

7 

38.94 

46.20 

6 

33.71 

40.40 

6 

36.22 

43.19 

6 

39.00 

46.26 

5 

33.76 

40.47 

5 

36.28 

43.26 

5 

39.05 

46.32 

4 

33.82 

40.53 

4 

36.33 

43.32 

4 

39.10 

46.37 

3 

33.88 

40.60 

3 

36.39 

43.38 

3 

39.15 

46.42 

2 

33.94 

40.67 

2 

36.44 

43.44 

2 

39.20 

46.48 

1 

34.00 

40.74 

1 

36.50 

43.50 

1 

39.25 

46.53 

0 

34.05 

40.79 

0 

36.56 

43.56 

0 

39.30 

46.59 

0.9509 

34.10 

40.84 

0.9459 

36.61 

43.63 

0.9409 

39.35 

46.64 

8 

34.14 

40.90 

8 

36.67 

43.69 

8 

39.40 

46.70 

7 

34.19 

40.95 

7 

36.72 

43.75 

7 

39.45 

46.75 

6 

34.24 

41.00 

6 

36.78 

43.81 

6 

39.50 

46.80 

5 

34.29 

41.05 

5 

36.83 

43.87 

5 

39.55 

46.86 

4 

34.33 

41.11 

4 

36.89 

43.93 

4 

39.60 

46.91 

3 

34.38 

41.16 

3 

36.94 

44.00 

3 

39.65 

46.97 

2 

34.43 

41.21 

2 

37.00 

44.06 

2 

39.70 

47.02 

1 

34.48 

41.26 

1 

37.06 

44.12 

1 

39.75 

47.08 

0 

34.52 

41.32 

0 

37.11 

44.18 

0 

39.80 

47.13 

526 


APPENDIX. 


Percentage  of  Alcohol  by  Weight  and  by  Volume  from  the  Specific  Gravity 
(at  15.5°  C.),  by  Otto  Hehner.— Continued. 


Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

0.9399 

39.85 

47.18 

0.9349 

42.33 

49.86 

0.9299 

44.68 

52.34 

8 

39.90 

47.24 

8 

42.38 

49.91 

8 

44.73 

52.39 

7 

3995 

47.29 

7 

42.43 

49.96 

7 

44.77 

52.44 

6 

40.00 

47.35 

6 

42.48 

50.01 

6 

44.82 

52.48 

5 

40.05 

47.40 

5 

42.52 

50.06 

5 

44.86 

52.53 

4 

40.10 

47.45 

4 

42.57 

50.11 

4 

44.91 

52.58 

3 

40.15 

47.51 

3 

42.62 

50.16 

3 

44.96 

52.63 

2 

40.20 

47.56 

.2 

42.67 

50.21 

2 

45.00 

52.68 

1 

40.25 

47.62 

1 

42.71 

50.26 

1 

45.05 

52.72 

0 

40.30 

47.67 

0 

42.76 

50.31 

0 

45.09 

52.77 

0.9389 

40.35 

47.72 

0.9339 

42.81 

50.37 

0.9280 

45.55 

53.24 

8 

40.40 

47.78 

8 

42.86 

50.42 

70 

46.00 

53.72 

7 

40.45 

47.83 

7 

42.90 

50.47 

60 

46.46 

54.19 

6 

40.50 

47.89 

6 

42.95 

60.52 

50 

46.91 

54.66 

5 

40.55 

47.94 

5 

43.00 

50.57 

40 

47.36 

55.13 

4 

40.60 

47.99 

4 

43.05 

50.62 

30 

47.82 

55.60 

3 

40.65 

48.05 

3 

43.10 

50.67 

20 

48.27 

56.07 

2 

40.70 

48.10 

2 

43.14 

50.72 

10 

48.73 

56.54 

1 

40.75 

48.16 

1 

43.19 

50.77 

00 

49.16 

56.98 

0 

40.80 

48.21 

0 

43.24 

50.82 

0.9379 

40.85 

48.26 

0.9329 

43.29 

50.87 

0.9190 

49.64 

57.45 

8 

40.90 

48.32 

8 

43.33 

50.92 

80 

50.09 

57.92 

7 

40.95 

48.37 

7 

43.39 

50.97 

70 

50.52 

58.36 

6 

41.00 

48.43 

6 

43.43 

51.02 

60 

50.96 

58.80 

5 

41.05 

48.48 

5 

43.48 

51.07 

50 

51  ..38 

59.22 

4 

41.10 

48.54 

4 

43.52 

51.12 

40 

51.79 

59.63 

3 

41.15 

48.59 

3 

43.57 

51.17 

30 

52.23 

60.07 

2 

41.20 

48.64 

2 

43.62 

51.22 

20 

52.58 

60.52 

1 

41.25 

48.70 

1 

43.67 

51.27 

10 

53.13 

60.97 

0 

41.30 

48.75 

0 

43.71 

51.32 

00 

53.57 

61.40 

0.9369 

41.35 

48.80 

0.9319 

43.76 

51.38 

0.9090 

54.00 

61.84 

8 

41.40 

48.86 

8 

43.81 

51.43 

80 

54.48 

62.31 

7 

41.45 

48.91 

7 

43.86 

51.48 

70 

54.95 

62.79 

6 

41.50 

48.97 

6 

43.90 

51.53 

60 

55.41 

63.24 

5 

41.55 

49.02 

5 

43.95 

51.58 

50 

55.86 

63.69 

4 

41.60 

49.07 

4 

44.00 

51.63 

40 

56.32 

64.14 

3 

41.65 

49.13 

3 

44.05 

51.68 

30 

56.77 

64.58 

2 

41.70 

49.18 

2 

44.09 

51.72 

20 

57.21 

65.01 

1 

41.75 

49.23 

1 

44.14 

51.77 

10 

57.63 

65.41 

0 

41.80 

49.29 

0 

44.18 

51.82 

00 

58.05 

65.81 

0.9359 

41.85 

49.34 

0.9309 

44.23 

51.87 

0.8990 

58.50 

66.25 

8 

41.90 

49.40 

8 

44.27 

51.91 

80 

58.95 

66.69 

7 

41.95 

49.45 

7 

44.32 

51.96 

70 

59.39 

67.11 

6 

42.00 

49.50 

6 

44.36 

52.01 

60 

59.83 

67.53 

5 

42.05 

49.55 

5 

44.41 

52.06 

50 

60.26 

67.93 

4 

42.10 

49.61 

4 

44.46 

52.10 

40 

60.67 

68.33 

3 

42.14 

49.66 

3 

44.50 

52.15 

30 

61.08 

68.72 

2 

42.19 

49.71 

2 

44.55 

52.20 

20 

61.50 

69.11 

1 

42.24 

49.76 

1 

44.59 

52.25 

10 

61.92 

69.50 

0 

42.29 

49.81 

0 

44.64 

52.29 

00 

62.36 

69.92 

APPENDIX. 


527 


Percentage  of  Alcohol  by  Weight  and  by  Volume  from  the  Specific  Gravity 
(at  15.5°  C.),  by  Otto  Hehner.— Continued. 


Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

0.8890 

62.82 

70.35 

40 

77.71 

83.60 

0.8190 

91.36 

94.26 

80 

63.26 

70.77 

30 

78.12 

83.94 

80 

91.71 

94.51 

70 

63.70 

71.17 

20 

78.52 

84.27 

70 

92.07 

94.76 

60 

64.13 

71.58 

10 

78.92 

84.60 

60 

92.44 

95.03 

60 

64.57 

71.98 

00 

79.32 

84.93 

50 

92.81 

95.29 

40 

65.00 

72.38 

40 

93.18 

95.55 

30 

65.42 

72.77 

0.8490 

79.72 

85.26 

30 

93.55 

95.82 

20 

65.83 

73.15 

80 

80.13 

85.59 

20 

93.92 

96.08 

10 

66.26 

73.54 

70 

80.54 

85.94 

10 

94.28 

96.32 

00 

66.70 

73.93 

60 

80.96 

86.28 

00 

94.62 

96.55 

60 

81.36 

86.61 

0.8790 

67.13 

74.33 

40 

81.76 

86.93 

0.8090 

94.97 

96.78 

80 

67.54 

74.70 

30 

82.15 

87.24 

80 

95.32 

97.02 

70 

67.96 

75.08 

20 

82.54 

87.55 

70 

95.68 

97.27 

60 

68.38 

75.45 

10 

82.92 

87.85 

60 

96.03 

97.51 

60 

68.79 

75.83 

00 

83.31 

88.16 

60 

96.37 

97.73 

40 

69.21 

76.20 

40 

96.70 

97.94 

30 

69.63 

76.57 

0.8390 

83.69 

88.46 

30 

97.03 

98.16 

20 

70.04 

76.94 

80 

84.08 

88.76 

20 

97.37 

98.37 

10 

70.44 

77.29 

70 

84.48 

89.08 

10 

97.70 

98.59 

00 

70.84 

77.64 

60 

84.88 

89.39 

00 

98.03 

98.80 

50 

85.27 

89.70 

0.8690 

71.25 

78.00 

40 

85.65 

89.99 

0.7990 

98.34 

98.98 

80 

71.67 

78.36 

30 

86.04 

90.29 

80 

98.66 

99.16 

70 

72.09 

78.73 

20 

86.42 

90.58 

70 

98.97 

99.35 

60 

72.52 

79.12 

10 

86.81 

90.88 

60 

99.29 

99.55 

60 

72.96 

79.50 

00 

87.19 

91.17 

50 

99.61 

99.75 

40 

73.38 

79.86 

40 

99.94 

99.96 

30 
20 

73.79 
74.23 

80.22 
80.60 

0.8290 

80 

87.58 
87.96 

91.46 

91.75 

0.7939 

99.97 

99.98 

10 

74.68 

81.00 

70 

88.36 

92.05 

Absolute 

Alcohol. 

00 

75.14 

81.40 

60 

88.76 

92.36 

0.7938 

100.00 

100.00 

60 

89.16 

92.66 

0.8590 

75.59 

81.80 

40 

89.54 

92.94 

80 

76.04 

82.19 

30 

89.92 

93.23 

70 

76.46 

82.54 

20 

90.29 

93.49 

60 

76.88 

82.90 

10 

90.64 

93.75 

50 

77.29 

83.25 

00 

91.00 

94.00 

528 


APPENDIX. 


V.  Physical  and  Chemical  Constants  of  Fixed  Oils  and  Fats. 

(CHIEFLY  FROM  BENEDIKT-LEWKOWITSCH.) 


SpeC1afitClP.aVity 

Specific 

&&. 

Melting-point. 

Solidifying-point. 
C. 

Linseed  oil     .    . 

0.931-0.935 

0.880 

_16°  to  —20° 

—16° 

Hemp-seed,  oil 

0  925-0  931 

—  27° 

Walnut  oil                 .    . 

0.925-0.926 

0.871 

—27° 

Poppy-seed  oil           .    . 

0  924-0  927 

0  873 

—18° 

Niger-seed  oil     .... 

0.926-0.928 

0.874 

—9° 

Sunflower  oil          .    . 

0.924-0  926 

0  919 

—17° 

Fir-seed  oil             ... 

0.925  0  928 

—27°  to  —30° 

Madia  oil                 .        . 

0.926-0  928 

—11°  to  —15° 

Maize  oil                .    . 

0.921-0  924 

—10°  to  —15° 

Cotton-seed  oil  .... 

0.922-0.930 

0  867 

12° 

0.923-0.924 

0  871 

—5° 

Rape-seed  oil  

0.914-0.917 

0863 

_2°  to  —10° 

Black  mustard  oil     .    . 

0.916-0  920 

—17.5° 

Croton  oil    

0.942-0.955 

—16° 

0.960-0.966 

0.910 

—12°  to  —18° 

Apricot  kernel  oil      .    . 

0.915-0.919 

—14° 

Almond  oil     . 

0  915  0  920 

—10° 

Earth  nut  oil  .    . 

0  916  0  920 

0  867 

—  3°  to  —  7° 

Olive  oil  

0.914-0  917 

0  862 

2° 

Menhaden  oil     .... 

0.927-0.933 

—4° 

0.922-0  927 

0874 

0°  to  —10° 

Seal  oil    

0.924-0.929 

0.873 

3° 

Whale  oil       ... 

0.920-0.930 

0.872 

—2° 

Dolphin  oil     

0.917-0.918 

50  to  —3° 

0.926 

0.871 

—16° 

Neat's-foot  oil    .... 

0.914-0.916 

0.861 

0°  to  1.5° 

Cotton-seed  stearine  .    . 
Palm  oil  

0.919-0.923 
0.921-0.925 

0.867 
0.856 

40° 

27°  to  42° 

31°  to  32.5° 

Cacao  butter       .... 

0.950-0  952 

0  858 

30°  to  33° 

25°  to  26° 

Cocoa-nut  oil  

0.925-0  926 

0  873 

20°  to  26° 

1  6°  to  20° 

Myrtle  wax     

0.995 
0.970-0.980 

0,875 
0.875 

40°  to  44° 
51°  to  54.5° 

39°  to  43° 
46° 

Lard        .    . 

0  931  0  938 

0  861 

41°  to  46° 

29° 

Bone  fat  . 

0  914  0  916 

21°  to  22° 

15°  to  17° 

Tallow     

0.943-0.952 

0.860 

42°  to  46° 

35°  to  37° 

Butter  fat    

0  927-0  936 

0  866 

29  5°  to  33° 

19°  to  20° 

Oleomargarine    .... 

0.924-0.930 

0.859 

Sperm  oil    

0.875-0  884 

0  833 

—25° 

Bottle-nose  oil        ... 

0.879-0.880 

0.827 

Carnauba  wax    .... 
Wool-fat         .... 

0.990-0.999 
0  973 

0.842 
0  901 

84°  to  85° 
39°  to  42° 

80°  to  81° 
30°  to  30  2° 

Beeswax  

0  958  0  969 

0  822 

62°  to  64° 

60  5°  to  62° 

Spermaceti  .   »    . 

0  960 

0  812 

43  5°  to  49° 

43  4°  to  44.2° 

Chinese  wax  

0.970 

0  810 

80  5°  to  81° 

80.5°  to  81° 

APPENDIX. 


529 


V.  Physical  and  Chemical  Constants  of  Fixed  Oils  and  Pats. — 

Continued. 

(CHIEFLY  FROM  BENEDIKT-LEWKOWITSCH.) 


Saponification 
value. 

Maumen6 
test. 

Iodine  value. 

Hehner 
value. 

Reichert 
value. 

Jjinseed  oil 

189-195 

104°-111° 

170-181 

Hemp-seed  oil 

190-193 

95°-96° 

148 

Walnut  oil              ... 

194-197 

96°-101° 

144-147 

Poppy  -seed  oil    .... 
Niger-seed  oil  

193-197 
189-191 

86°-88° 
81°-82° 

134-141 
132.9 

95.38 

193-194 

72°-75° 

120-129 

95 

fir-seed  oil 

191  3 

98°-99° 

118.9-120 

192.8 

95°-99° 

117.5-119.5 

Maize  oil  
Cotton-seed  oil    .... 

188-190.4 
191-196 
187-191 

56°-60.5° 
68°-77° 
64°-68° 

117-122 
104-108 
105-109 

96 
96.17 
95.8 

2.5 
0.85 

Rape-seed  oil           .    .    . 

175-178 

51°-60° 

99-105 

95 

Black  mustard  oil  .    .    . 
Croton  oil    

174-174.6 
210  3-215 

430.440 

106.3 
101.7-104 

"  89  ' 

13.5 

Castor  oil     .   .       ... 

178-183 

46°-47° 

83.4-85.9 

1.4 

Apricot  kernel  oil  .    .    . 

192.2-193.1 

42.5°-46° 

100-101 

Almond  oil 

190  5  195  4 

51°-53° 

96-99 

96  2 

Earthnut  oil        .... 

190-197 

450.490 

95-98 

95.86 

Olive  oil  
Menhaden  oil  
Cod-liver  oil    . 

191-196 
189.3-192 

182-187 

41.5°-45.5° 
123°-128° 
102°-103° 

81.6-84.5 
147.9 
139-152 

95.43 
*95.3 

0.3 

1.2 

Seal  oil         .    . 

190-196 

92° 

125-130 

94.2 

0.22 

Whale  oil    

188-193 

91°-92° 

49 

93.5 

2.04 

T-K  i  i  .       .,  f  Body  oil  . 

197.3 

99.5 

93.07 

5.6 

Dolphin  oil  {J~yoii    ; 
T»        •       -if  Body  oil  . 

290 
216-218.8 

'50° 

32.8 

66.28 

65.92 
23.45 

Porpoise  oil  |Ja/oil    ^ 

253  7 

49.6 

68.41 

65.8 

Neat's-foot  oil 

194  3 

47°-48.5° 

69.3-70.4 

Cotton-seed  stearine  .    . 
Palm  oil 

194.6-195.1 
196  3  202 

48° 

88.7-92.8 
51-52.4 

96.3 
95  6 

05 

Cacao  butter    
Cocoa-nut  oil  ..... 

192.2-193.5 
250-253 



32-37 
8.5-9.3 

94.59 
88.6 

1.6 
3  7 

Myrtle  wax     

205  7-211  7 

10.7 

220-222.4 

4.2-6.6 

195.3-196.6 

27°-32° 

57-63 

96 

Bone  fat              .... 

190  9 

46  3-49  6 

Tallow          

195-198 

36-40 

95  6 

0  25 

Butter  fat     

221.5-227 

26-35 

87.5 

28  78 

55.3 

95-96 

2.6 

Sperm  oil                 . 

132  5  147 

47°  51° 

84 

1  3 

Bottle-nose  oil     .... 
Carnauha  wax     .... 

126-134 
80-84 

41°-47° 

77.4-82 
13  5 

.    .    . 

1.4 

Wool-fat  

98.2-102.4 
91-96 



25-28 
8.3-11 

.    .    . 

.    .    . 

Spermaceti               .    . 

128 

Chinese  wax    .    .    . 

63 

INDEX. 


Abel  tester  for  oils,  36 
Absinthe,  229 
Acetate  of  iron,  481 
Acetates,  analysis  of,  357 
Acetic  acid  production,  353 

ferment,  240 

Acetin  method  of  glycerine  analysis,  86 
Acetone,  354,  355 

in  wood-spirit,  357 
Acetophenone,  405 
Achroodextrine,  170 
Acid  brown  G,  417 

dyes,  412 

violet,  412 

yellow,  419 
Acidity  of  beer,  201 

of  tan-liquors,  336 
Acridine,  403 

yellow,  419 
Adjective  dyeing,  480 
Adulteration  of  beer,  201 
Aerated  bread,  237 
After-fermentation  of  beer,  195 
Agalite,  289 
Agar-agar,  339 
Albertite,  17 

Albuminoids  in  milk,  266 
Alcohol  in  beer,  200 

tables  of  Hehner,  622 
Alcoholic  beverages,  manufacture  of,  226 

fermentation,  184,  187 
Ale,  196 

Aleurometer  of  Boland,  238 
Algin,  339 
Alizarin,  420,  443 

black  S,  422 

blue,  421 
S,  421 

bordeaux  B,  421 

cyanine  R,  421 

dyeing,  487 

green  S,  421 

indigo-blue  S,  421 

manufacture,  410 

maroon,  421 

orange,  421 

red,  421 

yellow,  416 
A,  421 
0,421 

Alkali  blue,  412 
Almond  oil,  49 


Alpaca  fibre,  307 
Alum  tawing,  331 
Alumina  mordants,  481 
Aluminum  acetate,  481 
Amaranth,  417 
Amber,  97 

malt,  191 

Amidoazo  dyes,  416 
/>-Amidobenzene-sulphomc  acid,  402 
Amine  dye-colors,  412 
Ammonia  liquor,  valuation  of,  386 

recovery  of,  from  gas-liquor,  373 
Ammoniacal  cochineal,  454,  458 
Amylodextrine,  170 
Analysis  of  dyes,  427 

of  fats,  scheme  for,  83 
Aniline,  398 

black,  413 

dyeing,  487 

blue,  412 

hydrochloride,  398 

manufacture,  406 

red,  412 

rose,  413 

salt,  398 

still,  407 

sulphate,  398 
Animal  fibres,  bibliography  of,  316 

hide,  structure  of,  820 
Anime,  97 
Anisol  red,  417 
Annatto,  445 
Anthracene,  380,  385,  393 

brown,  421 

oil,  379 

series,  393 

sulphonic  acid,  401 

yellow,  422 
Anthracite  black,  418 
Anthragallol,  421 
Anthrapurpurin,  420 
Anthraquinone,  405,  409 

sulphonic  acid,  402,  409 
"Antichlor"  in  paper-bleaching,  288 
Antimony  mordants,  482 
Application  of  artificial  colors  to  cotton,  485 
Appolt's  coke-oven,  366 
Arachis  oil,  50 
Archil,  443 

substitute,  416 
Ardent  spirits,  manufacture  of,  215 

raw  materials  of,  216 
Argols,  203,  211 
Arrack,  227 

531 


532 


INDEX. 


Artificial  asphalts,  27 

butter,  256,  262 

camphor,  96 

coloring  matters,  bibliography  of,  439 

dye-colors,  statistics  of,  440 

indigo,  420 

rubber,  111 

silk,  313 

Asboth  method  for  starch,  180 
Ash  of  raw  sugars,  composition  of,  160 
Asphalt,  occurrence  of,  16 
Asphalts,  analysis  of,  42 

artificial,  27 

composition  of,  17 
Assouplissage,  313 
Atlas  powder,  77 
Auramine,  413 
Aurantia,  414 
Aureosin,  414 
Aurin,  414 

Autoclave  process  for  fats,  68 
Avignon  berries,  445 
Azines,  413 
Azo  blue,  419 

dye-colors,  416 

mauve,  419 
Azococcin  7B,  417 

2R,  416 
Azolitmin,  448 
Azorubin  S,  417 
Azurine,  415 


Bacterial  fermentation,  184 
Bagasse,  155 
Bahia-wood,  441 
Baking,  chemistry  of,  235 

powders,  234 
Balata,  100 
Balsams,  97 
Bar-wood,  441 
Basic  dyes,  412 
Bast  fibres,  273 
Bastards,  152 
Bastose,  273 
Baume's  scale  for  liquids  heavier  than  water, 

511 

for  liquids  lighter  than  water,  610 
Bavarian  thick-mash  process,  191 
"Bayer's  acid,"  402 
Beating  machine  for  paper-pulp,  289 
Becchi's  test,  83 
Beck's  scale  for  liquids  heavier  than  water 

611 

"Bee-hive"  coke-ovens,  365 
Beer,  analysis  of,  199 

fall,  194 

ferment,  185 

production  in  the  United  States,  249 
Beeswax,  52 
Ben  oil,  60 
Benzal-chloride,  395 
Benzaldehyde,  404 

green,  412 
Benzene,  391 

disulphonic  acid,  401 

hydrocarbons,  391 


Benzene  sulphonic  acid,  401 
Benzidine,  400 

dyes,  418 

Benzine  distillate,  23 
properties  of,  30 
Benzoaurine,  419 
Benzoic  acid,  404,  408 

aldehyde,  404 
Benzo-indigo-blue,  419 
Benzol,  tests  for,  382 
Benzophenone,  404 
Benzopurpurin,  418 
Benzo-trichloride,  395 
Benzyl  chloride,  395 
Biebrich  scarlet,  417 
Bismarck  brown.  417 
Bisulphite  process  for  wood-pulp,  283 
Bituminous  coal,  358 

shales,  27 
Bixin,  445 

Black  dyes,  recognition  of,  on  fibre,  438 
iron  liquor,  481 
seed  cotton,  275 
Blasting  gelatine,  77 
Blauholz,  447 
Bleached  lac,  98 
Bleaching  agents,  478 

dyeing,   and  textile  printing,  bibliog- 
raphy of,  502 
kiers,  475 
of  paper-pulp,  286 
of  wool,  311 
processes,  472 

Bloom  in  petroleum  oils,  30 
Blotting-paper,  292 
Blown  oils,  74 

Blue  dyes,  recognition  of,  on  fibre,  435 
Bock-beer,  197 
Boiled  oil,  73 
"Boiled-off"  liquid,  309,  312 

silk,  312 

Boiley's  blue,  460 
Boiling  of  linseed  oil,  102 
Bois  de  Bresil,  441 

de  Campeche,  447 
Bone-black,  analysis  of,  163 
exhausted,  155 
filters  for  sugar,  137 
revivifying  of,  150 
Bone  fat,  51 

glue,  341,342 
Bordeaux  B,  417 

G,  418 
Borneol,  97 

Bottom  fermentation,  195 
Brandy,  227 
Brasilein,  441 
Brasilin,  441,  456 
Brazil-wood,  441 
Bread,  adulteration  of,  239 
analyses  of,  236 
method  of  analysis  of,  237 
Bread-making,  231 
Brilliant  Congo  G,  418 
crocein,  417 
green,  412 
ponceau  4R,  417 
British  gum,  177 


INDEX. 


533 


Bromine  absorption  of  fats,  81 
a-Brom-naphthalene,  395 
Brown  acetate  of  lime,  353 

coal,  359 

dyes,  recognition  of,  on  fibre,  437 

malt,  191 

Burmese  lacquer,  100 
Burning  naphtha,  375 
Butter,  261 

analysis  of,  267 

coloring  matter  of,  270 

fat,  51,  267 

manufacture  of,  254,  256 

yellow,  416 
Butterine,  256,  262 
Button-lac,  98 
By-product  coke-ovens,  366,  388 


Cacao  butter,  50 
Cachou  de  Laval,  422 
Calcium  acetate,  353 
Caliatur-wood,  441 
Calorisators,  or  juice-warmers,  139 
Camel's-hair  fibre,  307 
Camembert  cheese,  262 
Camphors,  95,  97 
Cam-wood,  441 
Candle  manufacture,  69 
Candle-making  materials,  69 
Cane-sugar,  bibliography  of,  166 
Cannel  coal,  359 
Caoutchouc,  99,  105,  111 

statistics  of,  119 
Capri  blue,  415 
Caramel  coloring,  175 

in  spirits,  231 
Carbazol  yellow,  419 
Carbolic  acid,  377,  384 
Carbonatation  process,  133,  144 
Cardboard,  292 
Carded  wool,  314 
Carmine  naphte,  416 

preparation  of,  454 

red,  444 

Carminic  acid,  444 
Carmoisin,  417 
Carnauba  wax,  51 
Carthamic  acid,  443 
Carthamin,  443 
Casein  of  milk,  252 

preparations,  264 
Cashmere  wool,  307 
Cassonade  sugars,  152 
Castile  soap,  63 
Castor  oil,  48 
Catechin,  449 
Catechu,  449,  482 

extract,  322,  465 
Catechutannic  acid,  323,  449 
Caustic  soda,  479 
Celluloid,  298,  300 
Cellulose  nitrates,  295 

xanthogenate,  313 
Centrifugals,  132 
Cerasine,  417 


Cereals,  composition  of,  169 
Ceresine,  26,  31 
Chamois  leather,  332,  334 
Champagnes,  209 

manufacture  of,  206 
Chaptalization  of  wines,  205 
Charcoal  from  wood,  356 
Char-kilns,  150 
Chartreuse,  229 
Cheddar  cheese,  262 
Cheese,  analysis  of,  270 

making,  259 

varieties  of,  262 
Chemic  blue,  460 
Chemical  wood-pulp,  282 
Chestnut- wood  in  tanning,  322 
China-grass,  279 
Chinese  green,  448 

isinglass,  339 

lacquer,  100 

wax,  52 
Chinoline,  402 

Chloride  of  lime  bleaching,  478 
Chlorophyll,  448 
"Chlor-ozone,"  479 
Chondrin,  338 
Chromatropes,  418 
Chrome  tanning,  331 
"Chroming"  of  wool,  480 
Chromium  mordants,  482 
Chromogens,  411 
Chromophor  groups,  411 
Chrysamine,  419 
Chrysaniline,  420 
Chrysene,  394 
Chrysoidine,  416 
Chrysophenine,  418 
Chrysorhamnin,  445 
Cider  vinegar,  manufacture  of,  243 
Cingalese  lacquer,  100 
Clayed  sugars,  152 
Cleansing  of  fibres,  472 
Clerget's  process  of  inversion,  158 
Cloth  brown,  418 

red  G,  417 

Coal  distillation,  statistics  of,  388 
Coals,  composition  of,  360 
Coal-tar  colors  on  wool,  490 

pitch,  381,  386 

statistics,  389 

still,  369 
Coccerin,  444 
Cochineal,  444 

analysis,  465 

carmine,  444,  458 

red  A,  417 

scarlet  2R,  416 
Cocoa-nut  fibre,  280 

oil,  50 

Cod-liver  oil,  51 
Coefficient  of  expansion  of  petroleum  oils, 

510 
Coerulein,  415 

S,  415 

Coffey  still,  222 
Cognac,  227 
Coir  fibre,  280 
Coke-oven  distillation  of  coal,  365 


534 


INDEX. 


Coking  coals,  359 

Cold  process  of  soap-making,  64 

test  for  oils,  38 

vulcanization  process,  106 
Collodion,  298,  299 
Cologne  glue,  342 
Colophony  resin,  96,  98 
Colorimetric  tests  for  oils,  42 
Coloring  for  paper-pulp,  290 

matter  in  wines,  215 

recognition  of,  in  paper,  295 
Colza  oil,  50 
Combed  wool,  314 
Combination  tanning,  331 
Commercial  indigo,  composition  of,  469 
Comparative  dye  trials,  422 
Comparison  of  Twaddle  scale  with  rational 

Baume  scale,  513 
Composition  of  gas  liquor,  371 
Compression  test  for  paraffine,  41 
Concrete  sugar,  152 
Condensed  milk,  253,  260 
Congo  Corinth  G,  418 

G  and  P,  418 

group  of  dyes,  418 

red,  418 

yellow,  418 
Consumption  of  malt  liquors  in  the  United 

States,  249 
Copal,  97 

varnish,  103 
Coppee  coke-oven,  366 
Copper  mordants,  482 

wall  in  sugar  extraction,  128 
Cordite,  78 
Coriin,  321 
Corn  oil,  49 
Cotton  bleaching,  473 

dyeing,  484 

fibre,  274 

scarlet,  417 

seed  oil,  48 

products  from,  73 

statisties  of,  302 
Cow's  milk,  252 
Crackers,  237 
Cracking  of  petroleum,  19 
Cream  separators,  255 
Cremometer,  use  of,  266 
Creosote,  356 

oil,  378,  384 

Creosoting  of  timber,  379 
Crocein  orange,  416 

scarlet  3B,  417 
Crop-madder,  442 
Crown  leather,  334 
Crude  petroleum,  analysis  of,  33 
Crystallized  grape-sugar,  174 
Cudbear,  443 
Cumidine  red,  417 
Curacoa,  229 
Curcuma,  446 
Curcumin,  446 
Curd  of  milk,  253 
Curing  of  sugar  crystals,  132 
Cut  soaps,  63 
Cutch,  449 

in  tanning,  322 


Cyanine,  419 
Cyanosine,  414 
Cyclamine,  414 
Cylinder  oils,  30 
Cymogene,  29 


Dammar  resin,  98 

Decoction  process  of  mashing,  191,  192 
Defecation  of  sugar-juice,  128 
Degommage,  312 
Degraissage,  310,  313 
Degras,  333,  335 
Degreasing  of  wool,  310 
Delta-purpurin  5B,  419 
Demerara  crystals,  152 
Dephlegmators,  220 

Destructive  distillation,  bibliography  of,  387 
of  coal,  358 
of  wood,  347 
theory  of,  347 
Desuintage,  310 
Dextrine,  analyses  of,  177 

manufacture  of,  175 
Dextropinene,  96 
Diagram  of  coal-tar  distillation,  372 

of  distillation  of  coal,  362 
Diamidoazobenzene  hydrochloride,  416 
Diamine  black,  418 

blue,  418 

brown,  418 

gold,  418 

green,  418 

scarlet,  418 

Diazo-amido-benzene,  403 
Diazo-benzene  chloride  403 
Diazo-benzene-sulphonic  acid,  403 
Diazo-  compounds,  403 
Diazotizing,  410 
Dibrom-anthracene,  396 
Dichlor-anthracene,  396 
Diffusion  cells,  141 

process  in  extracting  sugar,  138 
Dimethylaniline,  399 

orange,  416 
Dimethylbenzene,  392 
Dinitrobenzene,  396 
a-Dinitronaphthalene,  398 
/3-Dinitronaphthalene,  398 
Dinitrosoresorcin,  415 
Dinitrotoluenes,  397 
Dioxine,  415 
Diphenyl,  393 
Diphenylamine,  400 

blue,  412 

orange,  416 

Diphenyl-methane  dyes,  413 
Direct  printing  processes,  492 
Discharges  in  calico-printing,  494,  500 
Diseases  of  wines,  204 
Distillation  of  fermented  mash,  220 

of  petroleum,  19,  21 

of  sawdust,  350 

of  wood,  349 
Distilled  spirit,  rectification  of,  223 

spirits,   production  of,   in  the  United 
States,  250 


INDEX. 


535 


Distiller's  residues,  230 

Distinctions  between  two  naphthols,  401 

between  vegetable  and  animal  fibres, 

315 

Disulphonic  acids  of  /?-naphthol,  402 
Diterpenes,  95 
Divi-divi,  323 

Double-effect  vacuum-pans,  132 
Dough,  preparation  of,  235 
Dry  wines,  208 
Dryers  for  oils,  74 
Drying  oils,  53 
Dyeing  processes,  483 
Dye-wood  extracts,  manufacture  of,  451 

extraction  of,  452 
Dye-woods,  curing  of,  449 
Dynamite,  72,  77 

analysis  of,  87 


Eau  de  vie  de  marc,  227 

Ebonite  or  hard  rubber,  111 

Ecru  silk,  312,  313 

Effervescing  wines,  manufacture  of,  206 

Eidam  cheese,  262 

Elution  process  for  molasses,  147 

Enamelled  leather,  333 

Enfleurage,  94 

Engine-sizing  for  paper,  290 

Engler  viscosimeter,  40 

Eosins,  414 

Erythrodextrine,  170 

Erythrosin,  414 

Erythrozym,  443 

Esparto,  280,  282 

Essential  oils,  adulteration  of,  112 

bibliography  of,  116 

classification  of,  95 

extraction  of,  94 

statistics  of,  117 
Ethyl  eosin,  414 

naphthalene,  393 
Eurhodines,  413 
Evrard  process,  55 
Examination  of  dyed  fabrics,  428 
Extract  determination  in  beer,  199 

wool,  314 
Extraction  of  oil  seeds  by  solvents,  56 


Factitious  brandy,  227 

vinegars,  245 
Faints,  225 
Fast  brown,  417 
N,  416 

red  A,  417 

B,  417 

C,  417 

D,  417 
violet,  418 
yellow,  416 

Fastness  of  dyes  to  light,  422 

to  soaping,  422 

Fat  determination  in  milk,  206 
Fats  and  oils,  analysis  of,  78 


Fats  and  oils,  bibliography  of,  87 

statistics  of,  88 

Fatty  oils,  composition  of,  53 
Fehling's  solution,  preparation  of,  159 

use  of,  159 
Fermentation,  bibliography  of,  246 

nature  of,  184 

of  grape  juice,  203 

of  mash  for  spirits,  218 

of  wort,  195 

Fibre,  recognition  of,  in  papers,  293 
Fibroin,  309 

Fibro-vascular  bundles,  273 
"Fifty  per  cent,  benzol,"  375,  392 
Filled  soaps,  64 
Fire  test  of  oils,  34 
Fischer  viscosimeter,  39 
Fisetin,  445 
Fish-bladders,  339 

gelatine,  341 
Fixed  oils  and  fats,  physical  and  chemical 

constants  of,  528 
Flash-point  of  oils,  34 
Flavaniline,  419 
Flavine,  445,  455 
Flavopurpurin,  421 
Flax,  275 

statistics  of,  302 
Flour,  232 

adulterations  of,  239 

and  bread,  bibliography  of,  248 
Fluoranthene,  394 
Fluorene,  394 
Fluorescein,  409,  414 
Forcite,  77 

Formaldehyde  in  tanning,  332 
Fortified  wines,  manufacture  of,  207 
Fourdrinier  machine  for  paper,  290 
Fractional  separation  of  coal-tar,  368 
Fromage  de  Brie,  262 
Fryer  concretor,  134 
Fuchsine,  412 

S,  412 
Fuel  gas,  28 

Fusel  oil,  determination  of,  231 
Fustic,  444 
Fustin,  445 


G-aban-wood,  442 
Gallamine  blue,  415 
Gallanilic  indigo,  415 
Gallein,  414 
Gallic  acid,  404 
Gallipoli  oil,  73 
Gallisin,  170,  178 
Gallization  of  wines,  206 
Gallocyanine,  415 
Galloflavin,  422 
Gambier  in  tanning,  322 
Gambine,  415 
Gas  purifiers,  364 

retort  distillation  of  coal,  362 
Gasolene,  29 

Gay-Lussac  specific  gravity  scale,  614 
Gelatine  dynamite,  77 
Gelbbeeren,  445 


536 


INDEX. 


Gilsonite,  16 

Gin,  228 

Glucose,  analyses  of,  177 

determination  of,  159 

manufacture  of,  172 

method  for  analysis  of,  180 

vinegar,  244 
Glue,  analysis  of,  343 

and  gelatine  manufacture,  338 

stock,  338 

Gluten  in  bread,  238 
Glutin,  338 
Glycerine  manufacture,  70 

properties  of,  76 

refining  of,  71 

statistics  of,  93 
Golden  syrup,  154 

Graham's  method  for  glucose  analysis,  181 
Grain  mash,  217 
Grape,  composition  of,  202 

sugar  and  glucose  statistics,  182 
manufacture  of,  172 

varieties  of,  201 
Gray  acetate  of  lime,  353 
Green  dyes,  recognition  of,  on  fibre,  435 

seed  cotton,  275 
.  syrup,  154 
Gruyere  cheese,  262 
Guanaco  fibre,  307 
Guarancine,  443,  454 
Gum  arabic,  97 

resins,  97 

Gun-cotton,  296,  299 
Gutta-percha,  99,  107,  111 

statistics  of,  119 

vulcanization  of,  107 


H 


Haematein,  448 
Haematoxylin,  448 
"Half-stuff"  paper-pulp,  286 
Halogen  derivates  of  benzene,  395 
Hand-made  paper,  290 
Hansen's  yeast  cultures,  185 
Hard  biscuit,  237 

fibre,  293 

rubber,  111 

soaps,  62 

Harness  leather,  329,  333 
Heat,  effect  of,  on  wood,  348 
Heavy  oil,  378 
Hehner's  method,  268 
Helianthin,  416 
Heliotrope,  419 
Hemiterpenes,  95 
Hemlock  bark  in  tanning,  322 
Hemp  fibre,  277 
Hemp-seed  oil,  48 
Henequen  fibre,  278 
Hercules  powder,  77 
Hermite  bleaching  process,  288,  476 
Hessian  purple,  418 

violet,  418 

yellow,  418 
Heumann's  tester,  3  7 
Hexanitrate  of  cellulose,  295 


Hide  glue,  339,  342 

Hides,  varieties  of,  321 

High  and  low  heat,  effect  of,  on  coal,  361 

milling  process,  233 
Hochst  new  blue,  412 
Hofmann's  violets,  412 
Hollander  for  paper  stock,  284 
"Hollands,"  228 
Hop  production,  statistics  of,  248 
Hops,  188,  189 

in  manufacture  of  beer,  194 
Horsechestnut-bark  in  tanning,  322 
Hubl's  method,  82,  268 
Huile  tournante,  73 
Hydrogen  peroxide,  479 
bleaching,  478 
Hydrolysis  of  starch,  results  of,  170 


Identification  of  coal-tar  dyes,  424 
Illuminating  gas,  analysis  of,  386 

composition  of,  365 
Imitation  wines,  manufacture  of,  207 
Indamines,  415 
Indian  lacquer,  100 
India-rubber  99,  105,  111 
Indican,  446 
Indiglucin,  446 
Indigo,  446 

analyses  of,  466 

carmine,  455,  459 
synthesis  of,  460 

commercial  varieties  of,  459 

disulphonic  acid,  455 

extract,  456 

monosulphonic  acid,  455 

plant,  treatment  of,  446 

printing,  498 

purple,  460 

salt,  420 

substitute,  413,  461 

vat  dyeing,  484 

white,  447 
Indoines,  413 
Indophenol,  415 

white,  415 
Indulines,  413 
Indurated  fibre,  293 
Infusion  process  of  mashing,  191,  192 
Ingrain  colors,  419 

red  dyeing,  488 
Insect  wax,  52 

Invert  sugar,  determination  of,  159 
Iodine  absorption  of  fats,  82 

compound  with  starch,  169 

number,  269 
Iron  mordants,  481 
Isinglass,  339,  342 

adulteration  of,  343 
Isopurpurin,  420 


Jaggery  sugar,  152 
Jameson  coke-oven,  368 
Japan  wax,  51 


INDEX. 


537 


Japanese  lacquer,  100 
Japans,  109 

Jebb  process  for  starch,  171 
Juice-warmers,  139 
Jute  bleaching,  477 

fibre,  277,  282 

statistics  of,  303 

K 

Kaiserschwarz,  461 
Kaseleim  pulver,  265 
Kauri  resin,  98 
Kephir,  264 
Kermes,  444 
Kerosene,  30 
Kino,  449 

in  tanning,  323 

red,  449 
Kinoin,  449 
Kirschwasser,  227 
Knoppern,  324 
Koettstorfer's  method,  268 
Koumiss,  264 
Krapp,  442 


Lac  dye,  444 

resin,  98 

Laccainic  acid,  444 
Lacquers,  100,  103 
Lactarine,  265 
Lactobutyrometer,  266 
Lactometer,  use  of,  265 
Laevo-pinene,  96 
Lager-beer,  196 
Lamp-black,  29 
Lanolin,  52 
Lard,  51 

cheese,  259,  263 

oil,  61 

Lead  acetate,  355 
Leather,  analysis  of,  338 

and  glue,  bibliography  of,  343 

industry,  statistics  of,  344 
Leed's  scheme  for  soap  analysis,  85 
Leguminous  starches,  168 
"  Leuco"  compounds,  411 
Light  oil  of  tar,  374 
Lignite,  359 

for  clarifying  sugar  juice,  129 
Ligroine,  30 
Lillie  evaporator,  132 
Lima  oil,  refining  of,  24 

wood,  441 

Limburger  cheese,  262 
Lime  and  copperas  vat  for  indigo,  484 

sucrate  process  for  molasses,  147 

use  of,  in  defecating  sugar  juice,  129 
Liming  of  hides,  325 
Lin  en- bleaching,  476 
Linoleum,  105,  110 
Linseed  oil,  49 

caoutchouc,  111 
varnishes,  101,  108 
Liqueurs,  228 
Liquid  glue,  342 


Litho-carbon,  17 

Litmus,  448,  461 

Llama  fibre,  307 

Loading  material  for  paper-pulp,  289 

Logwood,  447 

dyeing,  485 

extracts,  461,  464 
Lokanic  acid,  449 
Lokao,  448 
Lokaonic  acid,  448 
Lokaose,  449 
Long-stapled  wool,  305 
Low  wines,  223 
Lubricating  oils,  30 
Lunge's  bleaching  process,  476 
Lupulin,  188 
Lustre  wools,  306 
Luteolin,  445 
Lyddite,  78 

M 

Maceration  process  for  sugar-beets,  138 
Machine-made  paper,  290 
Maclurin,  445 
Madagascar-wood,  442 
Madder,  442 

bleach,  473 

flowers,  443 
Magdala  red,  413 
Magenta,  412 
Maize  oil,  49 
Malachite  green,  412 
Malt,  analysis  of,  197,  198 

composition  of,  188 

liquor  industry,  187 

substitutes,  194 

vinegar,  manufacture  of,  243 
Maltha,  16 
Malting  and  brewing,  bibliography  of,  246 

process,  189 
Maltodextrine,  170 
Maltose,  manufacture  of,  174 

properties  of,  177 
Manchester  yellow,  414 
Mandarin,  417 

Manganese  bronze  styles,  600 
Manila  hemp,  278 
Manufacture  of  vinegar,  bibliography  of, 

Maraschino,  229 

Marc  of  grapes,  211 

Marseilles  soap,  63 

Martin's  process  for  wheat  starch,  172 

Martius  yellow,  414 

Mash  process,  191 

Masse-cuite,  129,  132 

Mastic,  98 

Mather-Thompson  process,  475 

Mauvein,  413 

Mechanical  malting  apparatus,  190 

wood-pulp,  282 
Melada  sugar,  152 
Meldola's  blue,  415 
Melinite,  78 

Melis,  or  lump-sugar,  145 
Melting-point  of  fats,  method  for,  79 
Menhaden  oil,  52 


538 


INDEX. 


Menthol,  97 
Metanil  yellow,  416 
Methyl  alcohol,  355 

in  wood-spirit,  357 
purification  of,  354 

aniline,  398 

anthracene,  394 

benzene,  392 

eosin,  414 

green,  412 

naphthalene,  393 

quercetin,  445 

violet,  412 
Methylene  blue,  415 

violet,  413 

a-Methyl-quinoline,  403 
Metric  system,  505 
Mica  powder,  77 
Middle  oil,  377 
Milk  analysis,  265 

components  of,  253 

composition   of   different  varieties  of, 
251 

industries,  bibliography  of,  270 
statistics  of,  271 

sugar,  252,  263 
Milling  of  soaps,  66 
Millon's  reagent,  315 
Milly  process  of  saponification,  69 
Mimosa-bark,  323 
Mineral  tanning,  329 
Mixing  syrup,  154 
Mohair,  307 
Molasses,  analyses  of,  161 

from  sugar-beet,  146 

from  sugar-cane,  145 
Monochlor-anthracene,  396 
Mononitronaphthalene,  397 
Mordanting,  480 
Moric  acid,  445 
Morin,  445 
Moritannic  acid,  445 
Morocco  leather,  329,  333 
Morse  and  Burton's  method,  268 
Mould  growth  fermentations,  184 
"Mull-madder,  "442 
Mungo,  314 
Muscovado  sugar,  152 
Must  of  grapes,  202 
Mycoderma  aceti,  240 
Myrobalans  in  tanning,  323 
Myrtle  wax,  51 

N 

Nankin  cotton,  274 
Naphtha  from  petroleum,  29 
Naphthalene,  378,  384,  393 

red,  413,  418 

sulphonic  acids,  401 

tetrachloride,  395 
Naphthion  red,  416 
Naphthol  black,  418 

blue-black,  419 

sulphonic  acids,  401 

yellow,  414 
S,  414 
a-Naphthol,  400,  408 


a-Naphthol  blue,  415 
a-Naphthol  orange,  417 
/3-Naphthol,  400,  408 
/3-Naphthol  orange,  417 
Naphthyl  blue,  413 
/3-Naphthyl-bromide,  396 
/3-Naphthyl-chloride,  395 
Naphthylamine  black,  418 

brown,  416 

sulphonic  acid,  402 
a-Naphthylamine,  399 
/?-Naphthylamine,  399 
Natural  dye-colors  on  wool,  489 

dyestuffs,  bibliography  of,  469 
statistics  of,  469 

gas,  composition  of,  14 
occurrence  of,  13 
uses  of,  18 

varnishes,  100,  108 
Neat's-foot  oil,  51 
Nettle  fibre,  279 
Neufchatel  cheese,  262 
Neutral  oils,  30 

red,  413 

New  Zealand  flax,  280 
Nicaragua-wood,  441 
Nicholson's  blue,  412 
Nigrosine,  413 
Nile  blue,  415 

"  Ninety  per  cent,  benzol,"  375,  391 
Nitraniline,  399 
Nitration  of  cellulose,  297 
Nitroalizarin,  421 
Nitrobenzene,  396 

manufacture,  405 
Nitro-cellulose,  analysis  of,  300 
Nitro-glycerine,  71,  76 

analysis  of,  86 
Nitrometer,  300 
Nitroso  colors,  415 
Nitrotoluene,  897 
Non-coking  coals,  359 

drying  oils,  53 

lustre  wools,  306 
Nopal-plant,  444 
North  Carolina  pine  tar,  354 
Nutgalls,  324 

in  dyeing,  483 


Oak-bark  for  tanning,  321 

red,  322 
Oil-cloth,  105,  110 

manufacture  of,  105 
Oil-seed  cake,  72 

crushing,  55 
Oils  and  fats,  analysis  of,  78 

statistics  of,  88 
Oil-tanned  leather,  332 
Old  fustic,  444 
Oleomargarine,  70,  256,  258,  262 

cheeses,  263 
Oleo-resins,  97 
Olive  oil,  50 
Orange  IV,  416 

G,  416 
Orce'in,  443 


INDEX. 


539 


Orchil  extract,  457 

Orellin,  445 

Orlean,  445 

Orleans    process  of   vinegar  manufacture, 

241 
Orseille,  443 

carmine,  457 

purple,  457 
Orselline,  457 
Ortho-toluidine,  399 
Osmose  process  for  molasses,  146 
Otto  coke-oven,  368 
Oxidation  colors,  497 
Oxidized  oils,  74 
Oxyazine  colors,  415 
Oxyazo  dyes,  416 
Oxyketone  colors,  420 
Ozokerite,  occurrence  of,  16 

treatment  of,  26 


Padded  soaps,  64 
Paeonin,  414 
Pale  brandy,  227 

malt,  191 
Palm  oil,  50 
Paper  and  pulp,  statistics  of,  303 

making,  281 

mulberry  fibre,  283 

pulp  testing,  294 

sizing,  289 

washing  machine,  285 
Papier-mache,  292 
Paraffine,  crude,  occurrence  of,  16 

from  bituminous  shales,  28 

oil,  25,  32 

properties  of,  31,  356 
Paraphenylene  blue,  413 
Para-toluidine,  399 
Parchment,  334 

glue,  342 

paper,  292 

Parmesan  cheese,  262 
Pasteboard,  292 
Paste-dyes,  428 
Pasteur's  process  of  vinegar  manufacture, 

243 
Pasteurizing  of  beer,  196 

of  wine,  204,  205 
Patent  fuel  (briquettes),  381 

glue,  342 

leather,  333 
Peach-wood,  441 
Peanut  oil,  50 
Peat,  359 

Perfumes,  manufacture  of,  100 
Perkin's  violet,  413 
Pernambuco-wood,  441 
Persian  berries,  445 
Persio,  443. 

Petiotization  of  wines,  206 
Petrolatum,  25,  32 
Petroleum,  bibliography  of,  43 

Canadian,  15 

ether,  29 

Ohio,  nature  of,  15 

Pennsylvania,  nature  of,  15 


Petroleum,  Kussian,  15 

statistics,  44 
Phenanthrene,  394 
Phenetol  red,  417 
Phenol,  359,  377,  400 

dye-colors,  414 
Phenol-phthalein.  408 

sulphonic  acid,  401 
Phenols  in  tar,  tests  for,  383 
Phenyl-anthracene,  394 

methyl-ketone,  405 
Phenylene  brown,  416 
Phenylenediamine,  400 
Phlobaphene,  322 
Phosphine,  420 
Phosphotage  of  wines,  205 
Photogene,  31 
Phthaleins,  408 
Phthalic  acid,  404,  408 

anhydride,  408 

Physical  and  chemical  constants  of  fixed 
oils  and  fats,  528 

properties  of  fixed  oils,  52 
Picene,  394 
Picric  acid,  414 
Pigment  brown,  416 

styles  of  tissue-printing,  497 
Pincoffin,  457 
Pineapple  fibre,  280 
Pine-bark  in  tanning,  322 

tar,  354 
Pinoline,  110 
Plastering  of  wines,  205 
Plate  carthamine,  443 

red,  457 

Pneumatic  malting,  190 
Polarization  of  sugars,  157 
Polyterpenes,  95 
Pomades,  101 
Ponceau  B,  417 

2K,  417 

3K,  417 

4GB,  416 

4KB,  417 
Poppy-seed  oil,  49 
Porter,  196 

Potassium  carbonate,  479 
Potato  group  of  starches,  168 

mash,  218 

"Poteen"  whiskey,  228 
Preserved  milk,  254 
Press  for  oil  seeds,  56 
Pressure  flask  for  hydrolysis,  179 
Primary  disazo  colors,  417 
Primrose,  414 
Primuline  colors,  419 
Printer's  ink,  manufacture  of,  104 
Printing-paper,  292 

textile  fabrics,  492 
Proof  spirit,  226 
Propiolic  paste,  420 
Prune  pure,  415 

Purification  of  water  for  dyeing,  483 
Purpurin,  421,  443 
Pyrene,  394 
Pyridine,  402 
Pyrogallol,  400,  404 

manufacture,  407 


540 


INDEX. 


Pyroligneous  acid,  355 
Pyrolignite  of  iron,  355 
Pyronine,  413 
Pyroxyline  for  collodion,  296 

manufacture  of,  297 

varnishes,  299 


Quebracho-wood  in  tanning,  323 
Quercitannic  acid,  321,  445 
Quercitin,  445 
Quercitrin,  445 
Quercitron,  445 
Quick-vinegar  process,  242 
Quinaldine,  403 
Quinoline,  402,  410 

blue,  419 

red,  419 

yellow,  419 


Kaffinade,  153 
Bags  for  paper-making,  281 
Kamie  fibre,  279 
Kape  oil,  50 
Ratafia,  229 

Re.w  sugars,  analyses  of,  153 
analysis  of,  160 
refining  of,  135 

Recognition  of  dyes  on  the  fabric,  430 
Recovered  soda  from  paper-making,  293 
Rectified  spirit,  226 
Rectifying  distilled  spirit,  223 
Red  corallin,  414 

dyes,  recognition  of,  on  fibre,  430 

liquor,  481 

oil,  64 

sanders,  441 
Reeling  of  silk,  311 
Refining  of  vegetable  oils,  57 
Reichert-Meissl  figure,  269 
Reichert's  method,  268 
Rendement  or  refining  value,  153,  161 
Rendering  of  tallow,  55 
Resin  acids,  97 

separation  of,  83 
Resins,  nature  of,  97 

statistics  of,  118 

tests  for,  114 

Resists  in  calico-printing,  494,  600 
Resorcin,  400 

blue,  415 

brown,  417 

manufacture,  407 

phthalein,  409 
Retene,  394 
Retting  of  flax,  276 
Revivifying  bone-black,  150 
Rhamnetin,  445 
Rhigolene,  29 
Rhodamine,  414 
Rice  group  of  starches,  168 
Rin9age,  310 
Rocelline,  417 
Rolls  for  sugar-mills,  126 


Roquefort  cheese,  262 
Rose  Bengale,  414 
Rosin,  96 

grease,  110 

oil,  110 

in  mineral  oils,  115 

soaps,  64 

spirit,  110 
Rosolic  acids,  414 
Rothholz,  441 
Roxamine,  417 
Rubber  substitute,  111 

vulcanization  of,  106 
Ruberythric  acid,  443 
Ruffigallol,  421 
Rum,  228 
Russia  leather,  334 
Russian  glue,  342 


S 


Saccharomyces,  185 
Safllower,  443 

carmine,  443,  457 

extract,  457 

red,  457 
Saffrosine,  414 
Safranine,  413 
Sago  group  of  starches,  168 
Sandal-wood,  441 
Santalin,  441 
Santa-Martha-wood,  441 
Sapan-wood,  441 
Saponification  equivalent,  268 

of  fats,  58 

value  of  fats,  80 
Saxony  blue,  460 
Saybolt  tester  for  oils,  35 
"  Schaffer's  acid, "  402 
Scheelization  of  wines,  206 
Scheibler-Seyferth  elution  process,  147 
Schenk-beer,  196 
Schiedam  schnapps,  228 
Schlempe,  155,  230 
Scrap  rubber,  working  of,  107 
Sea-island  cotton,  274 
Sealing-wax,  140 
Secondary  disazo  dyes,  417 
Seed-hairs,  273 
Seed-lac,  98 

Self-raising  powders,  234 
Sericin,  309 
Sesame  oil,  50 
Sesquiterpenes,  95 
Shark  oil,  62 
Shellac,  98 
Shoddy,  314 
Short-stapled  wool,  306 
Silent  spirit,  222,  226 
Silk  bleaching,  478 

cocoons,  309 

conditioning,  311 

dyeing,  491 

fibre,  307,  314 

glue,  309 

scouring,  312 

statistics  of,  318 

worm,  development  of,  308 


INDEX. 


541 


Simon-Carves 's  coke-oven,  366 

Sisal  hemp,  278 

Size  glue,  342 

Sizing  materials,  recognition  of,  in  paper, 

295 

Skimmed  milk,   256 
Sludge  acid,  24 
Smokeless  powder,  78 
Soap  analysis,  scheme  for,  85 

coppers,  62 

frames,  65 

making,  60 
Soaps,  classification  of,  74 

composition  of,  75 

in  bleaching  operations,  479 
Sod  oil,  333,  335 
Soda  ash,  479 

crystals,  479 

process  for  wood-pulp,  282 
Sodium  chloride  in  dye-colors,  427 

peroxide,  479 

sulphate  in  dye-colors,  427 
Solar  oil,  32 
Soldaini's  solution,  160 
Sole-leather,  324,  333 
Solid  green,  412 
Soluble  blue,  412 

indigo,  455 

starch,  170 
Solvent  naphtha,  375 
Sorghum  cane,  analysis  of  juice  of,  125 

plant,  122 
Soudan  brown,  416 

G,  416 

Souple  silk,  312,  313 
Specific  gravity  tables,  510 
Sperm  oil,  52 
Spermaceti,  52 
Spindle  oils,  30 
Spirit  production  of  the  world,  250 

soluble  blue,  412 

varnishes,  104,  109 

vinegar,  244 
Spirits  and  distilled  liquors,  bibliography  of, 

247 
Starch  and  products,  bibliography  of,  182 

composition  of,  169,  176 

extraction  of,  from  corn,  170 
of,  from  potatoes,  172 
of,  from  wheat,  172 

method  for  analysis  of,  178 

statistics  of,  182 
Starches,  classification  of,  168 
Steam  styles  of  tissue-printing,  495 
Stearic  acid  manufacture,  66 
Steffen's  substitution  process,  147 
Stick-lac,  98,  444 
Stilbene,  393 
Stockholm  tar,  354 
Stoddard  tester,  38 
Stout,  196 

"Stoving"  of  woollen  yarns,  477 
Straw  for  paper-making,  282 
Strength  of  tanning  infusions,  determina- 
tion of,  335 
Stripping  of  silk,  312 
Strontium  process  for  molasses,  148 
Styles  of  tissue-printing,  495 


Substantive  cotton  dyes,  418 

dyeing,  480 

Sucrates,  analysis  of,  164 
Sucrose,  determination  of,  156,  158 
Sugar  beet,  121 

analysis  of  juice  of,  124 
composition  of,  123 

beets,  analysis  of,  162 

cane,  analysis  of  juice  of,  124 
composition  of,  121 

canes,  analysis  of,  162 

coloring,  manufacture  of,  175 

maple,  122 

of  lead,  355 

production  of,  from  sugar-cane,  125 
statistics  of,  166,  167 

yielding  materials,  121 
Sugars,  analysis  of,  160 
Sulphanil  yellow,  418 
Sulphanilic  acid,  402 
Sulphate  of  ammonia  statistics,  390 

of  magnesia  in  dye-colors,  424 
Sulphindigotic  acid,  455 
Sulpho-acetate  of  alumina,  481 

ricinoleic  acid,  73 
Sulphonating,  410 
Sumach  in  tanning,  323 
Sunflower  oil,  49 
Sunn  hemp,  278 
Surface  fermentation,  195 
Sweet  wines,  208 
Sylvestrene,  96 


Table    of    artificial    dye-colors    replacing 
natural  dyes,  501 

of  reactions  of  natural  dyestuffs,  468 

of    specific    gravity    figures,     degree 

Baume  and  degree  Brix,  515 
Tables  for  determination  of  temperature,  506 
Tabular  view  of  beet-sugar  working,  143 

of  production  of  sugar  from  cane, 

127 

Tagliabue  tester  for  oils,  85 
Tallow,  51 

extraction  of,  55 

oil,  51 
Tannin  as  mordant,  482 

containing  materials,  321 

determination  of,  335 

in  brandy  231 

in  wines,  214 
Tanning  extracts,  reactions  of,  337 

liquors,  327 

of  sole-leather,  diagram  of,  328 
Tar-stills  in  petroleum  refining,  22 
Tartar  emetic  as  mordant,  482 
Tartrazin,  419 
Tawed  leather,  334 
Tawing  processes,  329 
Terebene,  96 
Terpenes,  95 
Terpin  hydrate,  96 
Terpineol,  96 
Terra-firma-wood,  441 
Tetrabrom-fluorescein,  414 
Theory  of  tanning,  320 


542 


INDEX. 


Thermometer  scales,  comparison  of,  507 

Thiazines,  415 

Thick-mash  process,  191 

Thin-mash  process,  191 

"Thirty  per  cent,  benzol,"  392 

Thymol,  97 

Tin  mordants,  480 

spirits,  481 
Tissue-papers,  292 
Toddy,  227 
Toilet  soaps,  66 
Toluene,  392 

sulphonic  acid,  401 
Toluidine,  399 
Toluylen  red,  413 
Tournesol,  448 
Train  oil,  52 
Transparent  soaps,  76 
Treacle,  154 
Trinitro-cellulose,  295 

phenol,  414 

toluene,  397 

Triphenyl-methane  dyes,  412 
Triple-effect  vacuum-pan,  131 
Tropseolin  0O,  416 

OOO,  No.  1,  417 

000,  No.  2,  417 
Tub-sizing  for  paper,  289 
Turkey-red  process,  487 
Turmeric,  446 
Turpentine  oil,  96 

analysis  of,  113 
varnishes,  104,  109 
Tussur  silk,  309 

Twaddle's    scale  for  liquids   heavier  than 
water,  512 


U 


Unfermen table  carbohydrates,  178 

Unhairing  of  hides,  324 

Upland  cotton,  274 

Upper  leathers,  329,  333 

Usquebaugh,  229 

Utilization  of  fat,  scheme  for,  61 


Vacuum-pan  in  sugar  refining,  131 
Valonia,  323 

Valuation  of  tar  samples,  381 
Varnishes,  analysis  of,  116 

manufacture  of,  101 

varieties  of,  101 
Vaseline,  25,  32 

Vegetable  fibres,  bibliography  of,  301 
classification  of,  274 

glue,  339 

oils  and  fats,  48 

textile  fibres,  273 
Vellum,  334 
Vesuvine,  416 
Vicuna  fibre,  307 
Vigorite,  77 
Vin  de  raisin  sec,  207 
Vinasse,  165,  230 
Vinegar,  analysis  of,  245 


Vinegar,  manufacture  of,  240 

Violamine,  414 

Violet  dyes,  recognition  of,  on  fibre,  436 

Viscose,  313 

Viscosity  test,  39 

Volatile  oils,  94 

"Vomiting''  boiler  for  paper  stock,  284 

Vulcan  powder,  77 

Vulcanite,  107 

Vulcanization  of  rubber,  106 


W 

Walnut  oil,  49 

Water  for  dyeing,  483 

Wau,  445 

"Weighting"  of  silk,  491 

Weingartner's  dye-testing  tables,  424 

Weiss-beer,  197  * 

Weld,  445 

Wetzel  pan,  134 

Whale  oil,  52 

Wheat  group  of  starches,  168 

Whey,  265 

alcohol,  265 

butter,  265 

champagne,  265 

of  milk,  252 

vinegar,  265 
Whiskey,  228 
White  brandy,  227 
Wild  silks,  309 

Wiley's  method  for  glucose  analysis,  181 
Willesden  ware,  293 
Willow-bark  in  tanning,  322 
Wilson-G  wynne  process  for  fats,  59 
Wine,  consumption  of,  in  the  United  States, 
249 

ferment,  185 

production  of  the  world,  250 

vinegar,  244 
Wines,  analyses  of,  209,  210 

analysis  of,  212 

bibliography  of,  247 
Woad,  447 
Wood,  composition  of,  347 

fibre,  282 

naphtha,  351 

pulp,  recognition  of,  in  paper,  294 

spirit,  355 

purification  of,  353 

tar,  creosote  tests  for,  358 

production  and  treatment,  diagram 

of,  352 
treatment  of,  354 

vinegar,  purification  of,  351 
Wool,  305,  314 

black,  418 

bleaching,  477 

dyeing,  489 

fat,  306 

grease,  62 

perspiration,  306 

scarlet  R,  416 

scouring,  310 

statistics  of,  317 

yolk,  310 


INDEX. 


543 


Worsted  fabrics,  314 
"Wort,  preparation  of,  191 
of,  for  spirits,  217 
Wrapping-papers,  292 
Writing-papers,  292 


Xanthophyll,  448 
Xanthopurpurin,  443 
Xanthorhamnin,  445 
Xylene,  392 
Xylidine,  399 
red,  417 


Yaryan  evaporator,  132 

Yeast,  use  of,  in  bread,  233,  234 

Yeast-plant,  184 

Yellow  and  orange  dyes  on  the  fibres,  433 

corallin,  414 

Yield  from  distillation  of  wood,  350 
Young  fustic,  445 


Zapon  varnish,  299 

Zinc  chloride  treatment  of  paper,  293 

powder  vat  for  indigo,  485 
Zucker-couleur,  175 


THE   END. 


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